Merge commit '4b57416552ec2fa95216e2b044559f215723bf70' into melonDSi

88 files changed, 2428 insertions, 350 deletions

diff --git a/.github/workflows/build-ubuntu.yml b/.github/workflows/build-ubuntu.yml
new file mode 100644
index 0000000..fed0f3e
--- /dev/null
+++ b/.github/workflows/build-ubuntu.yml
@@ -0,0 +1,41 @@
+name: CMake Build (Ubuntu x86-64)
+
+on: [push, pull_request]
+
+env:
+  BUILD_TYPE: Release
+  CMAKE_VERSION: 3.15.2
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Install dependencies
+      shell: bash
+      working-directory: ${{runner.workspace}}
+      run: | # Fetch a new version of CMake, because the default is too old.
+        wget -nv https://github.com/Kitware/CMake/releases/download/v$CMAKE_VERSION/cmake-$CMAKE_VERSION-Linux-x86_64.tar.gz \
+        && tar -zxf cmake-$CMAKE_VERSION-Linux-x86_64.tar.gz \
+        && sudo rm -f /etc/apt/sources.list.d/dotnetdev.list /etc/apt/sources.list.d/microsoft-prod.list \
+        && sudo apt-get update \
+        && sudo apt-get install gtk+-3.0 libcurl4-gnutls-dev libpcap0.8-dev libsdl2-dev
+    - name: Create build environment
+      run: mkdir ${{runner.workspace}}/build
+    - name: Configure
+      shell: bash
+      working-directory: ${{runner.workspace}}/build
+      run: ${{runner.workspace}}/cmake-$CMAKE_VERSION-Linux-x86_64/bin/cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE
+    - name: Make
+      shell: bash
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        make -j$(nproc --all) \
+        && mkdir dist \
+        && cp {melonDS,romlist.bin} dist
+    - uses: actions/upload-artifact@v1
+      with:
+        name: melonDS
+        path: ${{runner.workspace}}/build/dist
diff --git a/.github/workflows/build-windows.yml b/.github/workflows/build-windows.yml
new file mode 100644
index 0000000..c7d05d0
--- /dev/null
+++ b/.github/workflows/build-windows.yml
@@ -0,0 +1,39 @@
+name: CMake Build (Windows x86-64)
+
+on: [push, pull_request]
+
+env:
+  BUILD_TYPE: Release
+
+jobs:
+  build:
+
+    runs-on: windows-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Install MSYS2
+      working-directory: ${{runner.workspace}}
+      run: | # Fetch MSYS2 build from XQEmu. Official distribution causes a CI failure due to permission errors.
+        Invoke-WebRequest -Uri "https://github.com/xqemu/ci-environment-msys2/releases/latest/download/msys64.7z" -OutFile "msys64.7z"
+        7z x -y msys64.7z "-oC:\tools\"
+        C:\tools\msys64\usr\bin\bash.exe -lc "pacman -Syuq --noconfirm"
+    - name: Install dependencies
+      run: C:\tools\msys64\usr\bin\bash.exe -lc "pacman -Sq --noconfirm git make mingw-w64-x86_64-{cmake,mesa,SDL2,toolchain}"
+    - name: Create build environment
+      run: |
+        New-Item -ItemType directory -Path ${{runner.workspace}}\melonDS\build
+        Copy-Item -Path ${{runner.workspace}}\melonDS -Destination C:\tools\msys64\home\runneradmin -Recurse
+    - name: Configure
+      run: |
+        C:\tools\msys64\usr\bin\bash.exe -lc "export PATH=`"/mingw64/bin:`$PATH`" \
+        && cd melonDS/build && cmake .. -G 'MSYS Makefiles' -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}"
+    - name: Make
+      run: |
+        C:\tools\msys64\usr\bin\bash.exe -lc "export PATH=`"/mingw64/bin:`$PATH`" \
+        && cd melonDS/build && make -j$(nproc --all) \
+        && ../msys-dist.sh"
+    - uses: actions/upload-artifact@v1
+      with:
+        name: melonDS
+        path: C:\tools\msys64\home\runneradmin\melonDS\build\dist
diff --git a/flatpak/net.kuribo64.melonds.yml b/flatpak/net.kuribo64.melonDS.yml
index dcc97b5..e336990 100644
--- a/flatpak/net.kuribo64.melonds.yml
+++ b/flatpak/net.kuribo64.melonDS.yml
@@ -1,5 +1,5 @@
 ---
-app-id: net.kuribo64.melonds
+app-id: net.kuribo64.melonDS
 runtime: org.freedesktop.Platform
 runtime-version: '18.08'
 sdk: org.freedesktop.Sdk
@@ -22,10 +22,8 @@ modules:
     buildsystem: cmake-ninja
     sources:
       - type: git
-        url: https://github.com/StapleButter/melonDS.git
-        commit: d4d4965b2fffc69958685a25a9d9fc0c78b54567
-      - type: file
-        path: net.kuribo64.melonds.desktop
+        url: https://github.com/Arisotura/melonDS.git
+        branch: master
     post-install:
-      - "desktop-file-install --dir=/app/share/applications net.kuribo64.melonds.desktop"
-      - "install -D icon/melon_256x256.png /app/share/icons/hicolor/256x256/apps/net.kuribo64.melonds.png"
+      - "desktop-file-install --dir=/app/share/applications net.kuribo64.melonDS.desktop"
+      - "install -D icon/melon_256x256.png /app/share/icons/hicolor/256x256/apps/net.kuribo64.melonDS.png"
diff --git a/flatpak/net.kuribo64.melonds.desktop b/flatpak/net.kuribo64.melonds.desktop
deleted file mode 100644
index e91f10d..0000000
--- a/flatpak/net.kuribo64.melonds.desktop
+++ /dev/null
@@ -1,8 +0,0 @@
-[Desktop Entry]
-Name=melonDS
-Comment=Nintendo DS emulator
-Exec=melonDS
-Type=Application
-Categories=Game;
-Terminal=false
-Icon=net.kuribo64.melonds
diff --git a/melon.rc b/melon.rc
index e2d8dc2..c6ee672 100644
--- a/melon.rc
+++ b/melon.rc
@@ -18,7 +18,7 @@ FILETYPE VFT_APP
 			VALUE "FileVersion", "0.8.3"
 			VALUE "FileDescription", "DS emulator, sorta. also 1st quality melon."
 			VALUE "InternalName", "SDnolem"
-			VALUE "LegalCopyright", "2016-2019 Arisotura & co."
+			VALUE "LegalCopyright", "2016-2020 Arisotura & co."
 			VALUE "LegalTrademarks", ""
 			VALUE "OriginalFilename", "zafkflzdasd.exe"
 			VALUE "ProductName", "melonDS"
diff --git a/melonDS.cbp b/melonDS.cbp
index 1f51dc9..eb77681 100644
--- a/melonDS.cbp
+++ b/melonDS.cbp
@@ -100,6 +100,10 @@
 		<Unit filename="melon.rc">
 			<Option compilerVar="WINDRES" />
 		</Unit>
+		<Unit filename="src/ARCodeList.cpp" />
+		<Unit filename="src/ARCodeList.h" />
+		<Unit filename="src/AREngine.cpp" />
+		<Unit filename="src/AREngine.h" />
 		<Unit filename="src/ARM.cpp" />
 		<Unit filename="src/ARM.h" />
 		<Unit filename="src/ARMInterpreter.cpp" />
@@ -137,6 +141,8 @@
 		<Unit filename="src/DSi_SPI_TSC.cpp" />
 		<Unit filename="src/DSi_SPI_TSC.h" />
 		<Unit filename="src/FIFO.h" />
+		<Unit filename="src/GBACart.cpp" />
+		<Unit filename="src/GBACart.h" />
 		<Unit filename="src/GPU.cpp" />
 		<Unit filename="src/GPU.h" />
 		<Unit filename="src/GPU2D.cpp" />
diff --git a/net.kuribo64.melonDS.desktop b/net.kuribo64.melonDS.desktop
new file mode 100644
index 0000000..c0dafe2
--- /dev/null
+++ b/net.kuribo64.melonDS.desktop
@@ -0,0 +1,11 @@
+[Desktop Entry]
+Name=melonDS
+GenericName=Nintendo DS Emulator
+Comment=A fast and accurate Nintendo DS emulator.
+Exec=melonDS
+Type=Application
+Categories=Game;Emulator;
+Terminal=false
+Icon=net.kuribo64.melonDS
+MimeType=application/x-nintendo-ds-rom;
+Keywords=emulator;Nintendo;DS;NDS;Nintendo DS;
diff --git a/src/ARCodeList.cpp b/src/ARCodeList.cpp
new file mode 100644
index 0000000..380481f
--- /dev/null
+++ b/src/ARCodeList.cpp
@@ -0,0 +1,38 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#include <stdio.h>
+#include "ARCodeList.h"
+
+/*
+    Action Replay code list format
+
+    header:
+    00 - magic MLAR
+    04 - version major
+    06 - version minor
+    08 - length
+    0C - number of codes
+
+    code header:
+    00 - magic MLCD
+    04 - name length
+    08 - code length
+    0C - enable flag
+    10 - code data (UTF8 name then actual code)
+*/
diff --git a/src/ARCodeList.h b/src/ARCodeList.h
new file mode 100644
index 0000000..b46510c
--- /dev/null
+++ b/src/ARCodeList.h
@@ -0,0 +1,33 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef ARCODELIST_H
+#define ARCODELIST_H
+
+#include "types.h"
+
+#define ARCL_MAJOR 1
+#define ARCL_MINOR 1
+
+class ARCodeList
+{
+public:
+    //
+};
+
+#endif // ARCODELIST_H
diff --git a/src/AREngine.cpp b/src/AREngine.cpp
new file mode 100644
index 0000000..2b6df65
--- /dev/null
+++ b/src/AREngine.cpp
@@ -0,0 +1,490 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include "NDS.h"
+#include "AREngine.h"
+
+
+namespace AREngine
+{
+
+typedef struct
+{
+    u32 Code[2 * 64]; // TODO: more sensible size for this? allocate on demand?
+    bool Enabled;
+
+} CheatEntry;
+
+// TODO: more sensible size for this? allocate on demand?
+CheatEntry CheatCodes[64];
+u32 NumCheatCodes;
+
+
+void ParseTextCode(char* text, int tlen, u32* code, int clen) // or whatever this should be named?
+{
+    u32 cur_word = 0;
+    u32 ndigits = 0;
+    u32 nin = 0;
+    u32 nout = 0;
+
+    char c;
+    while ((c = *text++) != '\0')
+    {
+        u32 val;
+        if (c >= '0' && c <= '9')
+            val = c - '0';
+        else if (c >= 'a' && c <= 'f')
+            val = c - 'a' + 0xA;
+        else if (c >= 'A' && c <= 'F')
+            val = c - 'A' + 0xA;
+        else
+            continue;
+
+        cur_word <<= 4;
+        cur_word |= val;
+
+        ndigits++;
+        if (ndigits >= 8)
+        {
+            if (nout >= clen)
+            {
+                printf("AR: code too long!\n");
+                return;
+            }
+
+            *code++ = cur_word;
+            nout++;
+
+            ndigits = 0;
+            cur_word = 0;
+        }
+
+        nin++;
+        if (nin >= tlen) break;
+    }
+
+    if (nout & 1)
+    {
+        printf("AR: code was missing one word\n");
+        if (nout >= clen)
+        {
+            printf("AR: code too long!\n");
+            return;
+        }
+        *code++ = 0;
+    }
+}
+
+
+bool Init()
+{
+    return true;
+}
+
+void DeInit()
+{
+    //
+}
+
+void Reset()
+{
+    memset(CheatCodes, 0, sizeof(CheatCodes));
+    NumCheatCodes = 0;
+
+    // TODO: acquire codes from a sensible source!
+    CheatEntry* entry = &CheatCodes[0];
+    u32* ptr = &entry->Code[0];
+
+    /*char* test = R"(9209D09A 00000000
+6209B468 00000000
+B209B468 00000000
+10000672 000003FF
+D2000000 00000000
+9209D09A 00000000
+94000130 FCBF0000
+6209B468 00000000
+B209B468 00000000
+200006B3 00000001
+200006B4 00000001
+D2000000 00000000
+9209D09A 00000000
+94000130 FC7F0000
+6209B468 00000000
+B209B468 00000000
+10000672 00000000
+D2000000 00000000)";
+    ParseTextCode(test, entry->Code, 2*64);
+    printf("PARSED CODE:\n");
+    for (int i = 0; i < 2*64; i+=2)
+    {
+        printf("%08X %08X\n", entry->Code[i], entry->Code[i+1]);
+    }
+    entry->Enabled = true;
+    NumCheatCodes++;*/
+}
+
+
+#define case16(x) \
+    case ((x)+0x00): case ((x)+0x01): case ((x)+0x02): case ((x)+0x03): \
+    case ((x)+0x04): case ((x)+0x05): case ((x)+0x06): case ((x)+0x07): \
+    case ((x)+0x08): case ((x)+0x09): case ((x)+0x0A): case ((x)+0x0B): \
+    case ((x)+0x0C): case ((x)+0x0D): case ((x)+0x0E): case ((x)+0x0F)
+
+void RunCheat(CheatEntry* entry)
+{
+    u32* code = &entry->Code[0];
+
+    u32 offset = 0;
+    u32 datareg = 0;
+    u32 cond = 1;
+    u32 condstack = 0;
+
+    u32* loopstart = code;
+    u32 loopcount = 0;
+    u32 loopcond = 1;
+    u32 loopcondstack = 0;
+
+    // TODO: does anything reset this??
+    u32 c5count = 0;
+
+    for (;;)
+    {
+        u32 a = *code++;
+        u32 b = *code++;
+        if ((a|b) == 0) break;
+
+        u8 op = a >> 24;
+
+        if ((op < 0xD0 && op != 0xC5) || op > 0xD2)
+        {
+            if (!cond)
+            {
+                if ((op & 0xF0) == 0xE0)
+                {
+                    for (u32 i = 0; i < b; i += 8)
+                        *code += 2;
+                }
+
+                continue;
+            }
+        }
+
+        switch (op)
+        {
+        case16(0x00): // 32-bit write
+            NDS::ARM7Write32((a & 0x0FFFFFFF) + offset, b);
+            break;
+
+        case16(0x10): // 16-bit write
+            NDS::ARM7Write16((a & 0x0FFFFFFF) + offset, b & 0xFFFF);
+            break;
+
+        case16(0x20): // 8-bit write
+            NDS::ARM7Write8((a & 0x0FFFFFFF) + offset, b & 0xFF);
+            break;
+
+        case16(0x30): // IF b > u32[a]
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u32 chk = NDS::ARM7Read32(a & 0x0FFFFFFF);
+
+                cond = (b > chk) ? 1:0;
+            }
+            break;
+
+        case16(0x40): // IF b < u32[a]
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u32 chk = NDS::ARM7Read32(a & 0x0FFFFFFF);
+
+                cond = (b < chk) ? 1:0;
+            }
+            break;
+
+        case16(0x50): // IF b == u32[a]
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u32 chk = NDS::ARM7Read32(a & 0x0FFFFFFF);
+
+                cond = (b == chk) ? 1:0;
+            }
+            break;
+
+        case16(0x60): // IF b != u32[a]
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u32 chk = NDS::ARM7Read32(a & 0x0FFFFFFF);
+
+                cond = (b != chk) ? 1:0;
+            }
+            break;
+
+        case16(0x70): // IF b.l > ((~b.h) & u16[a])
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u16 val = NDS::ARM7Read16(a & 0x0FFFFFFF);
+                u16 chk = ~(b >> 16);
+                chk &= val;
+
+                cond = ((b & 0xFFFF) > chk) ? 1:0;
+            }
+            break;
+
+        case16(0x80): // IF b.l < ((~b.h) & u16[a])
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u16 val = NDS::ARM7Read16(a & 0x0FFFFFFF);
+                u16 chk = ~(b >> 16);
+                chk &= val;
+
+                cond = ((b & 0xFFFF) < chk) ? 1:0;
+            }
+            break;
+
+        case16(0x90): // IF b.l == ((~b.h) & u16[a])
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u16 val = NDS::ARM7Read16(a & 0x0FFFFFFF);
+                u16 chk = ~(b >> 16);
+                chk &= val;
+
+                cond = ((b & 0xFFFF) == chk) ? 1:0;
+            }
+            break;
+
+        case16(0xA0): // IF b.l != ((~b.h) & u16[a])
+            {
+                condstack <<= 1;
+                condstack |= cond;
+
+                u16 val = NDS::ARM7Read16(a & 0x0FFFFFFF);
+                u16 chk = ~(b >> 16);
+                chk &= val;
+
+                cond = ((b & 0xFFFF) != chk) ? 1:0;
+            }
+            break;
+
+        case16(0xB0): // offset = u32[a + offset]
+            offset = NDS::ARM7Read32((a & 0x0FFFFFFF) + offset);
+            break;
+
+        case 0xC0: // FOR 0..b
+            loopstart = code; // points to the first opcode after the FOR
+            loopcount = b;
+            loopcond = cond;           // checkme
+            loopcondstack = condstack; // (GBAtek is not very clear there)
+            break;
+
+        case 0xC4: // offset = pointer to C4000000 opcode
+            // theoretically used for safe storage, by accessing [offset+4]
+            // in practice could be used for a self-modifying AR code
+            // could be implemented with some hackery, but, does anything even
+            // use it??
+            printf("AR: !! THE FUCKING C4000000 OPCODE. TELL ARISOTURA.\n");
+            return;
+
+        case 0xC5: // count++ / IF (count & b.l) == b.h
+            {
+                // with weird condition checking, apparently
+                // oh well
+
+                c5count++;
+                if (!cond) break;
+
+                condstack <<= 1;
+                condstack |= cond;
+
+                u16 mask = b & 0xFFFF;
+                u16 chk = b >> 16;
+
+                cond = ((c5count & mask) == chk) ? 1:0;
+            }
+            break;
+
+        case 0xC6: // u32[b] = offset
+            NDS::ARM7Write32(b, offset);
+            break;
+
+        case 0xD0: // ENDIF
+            cond = condstack & 0x1;
+            condstack >>= 1;
+            break;
+
+        case 0xD1: // NEXT
+            if (loopcount > 0)
+            {
+                loopcount--;
+                code = loopstart;
+            }
+            else
+            {
+                cond = loopcond;
+                condstack = loopcondstack;
+            }
+            break;
+
+        case 0xD2: // NEXT+FLUSH
+            if (loopcount > 0)
+            {
+                loopcount--;
+                code = loopstart;
+            }
+            else
+            {
+                offset = 0;
+                datareg = 0;
+                condstack = 0;
+                cond = 1;
+            }
+            break;
+
+        case 0xD3: // offset = b
+            offset = b;
+            break;
+
+        case 0xD4: // datareg += b
+            datareg += b;
+            break;
+
+        case 0xD5: // datareg = b
+            datareg = b;
+            break;
+
+        case 0xD6: // u32[b+offset] = datareg / offset += 4
+            NDS::ARM7Write32(b + offset, datareg);
+            offset += 4;
+            break;
+
+        case 0xD7: // u16[b+offset] = datareg / offset += 2
+            NDS::ARM7Write16(b + offset, datareg & 0xFFFF);
+            offset += 2;
+            break;
+
+        case 0xD8: // u8[b+offset] = datareg / offset += 1
+            NDS::ARM7Write8(b + offset, datareg & 0xFF);
+            offset += 1;
+            break;
+
+        case 0xD9: // datareg = u32[b+offset]
+            datareg = NDS::ARM7Read32(b + offset);
+            break;
+
+        case 0xDA: // datareg = u16[b+offset]
+            datareg = NDS::ARM7Read16(b + offset);
+            break;
+
+        case 0xDB: // datareg = u8[b+offset]
+            datareg = NDS::ARM7Read8(b + offset);
+            break;
+
+        case 0xDC: // offset += b
+            offset += b;
+            break;
+
+        case16(0xE0): // copy b param bytes to address a+offset
+            {
+                // TODO: check for bad alignment of dstaddr
+
+                u32 dstaddr = (a & 0x0FFFFFFF) + offset;
+                u32 bytesleft = b;
+                while (bytesleft >= 8)
+                {
+                    NDS::ARM7Write32(dstaddr, *code++); dstaddr += 4;
+                    NDS::ARM7Write32(dstaddr, *code++); dstaddr += 4;
+                    bytesleft -= 8;
+                }
+                if (bytesleft > 0)
+                {
+                    u8* leftover = (u8*)code;
+                    *code += 2;
+                    if (bytesleft >= 4)
+                    {
+                        NDS::ARM7Write32(dstaddr, *(u32*)leftover); dstaddr += 4;
+                        leftover += 4;
+                        bytesleft -= 4;
+                    }
+                    while (bytesleft > 0)
+                    {
+                        NDS::ARM7Write8(dstaddr, *leftover++); dstaddr++;
+                        bytesleft--;
+                    }
+                }
+            }
+            break;
+
+        case16(0xF0): // copy b bytes from address offset to address a
+            {
+                // TODO: check for bad alignment of srcaddr/dstaddr
+
+                u32 srcaddr = offset;
+                u32 dstaddr = (a & 0x0FFFFFFF);
+                u32 bytesleft = b;
+                while (bytesleft >= 4)
+                {
+                    NDS::ARM7Write32(dstaddr, NDS::ARM7Read32(srcaddr));
+                    srcaddr += 4;
+                    dstaddr += 4;
+                    bytesleft -= 4;
+                }
+                while (bytesleft > 0)
+                {
+                    NDS::ARM7Write8(dstaddr, NDS::ARM7Read8(srcaddr));
+                    srcaddr++;
+                    dstaddr++;
+                    bytesleft--;
+                }
+            }
+            break;
+
+        default:
+            printf("!! bad AR opcode %08X %08X\n", a, b);
+            return;
+        }
+    }
+}
+
+void RunCheats()
+{
+    // TODO: make it disableable in general
+
+    for (u32 i = 0; i < NumCheatCodes; i++)
+    {
+        CheatEntry* entry = &CheatCodes[i];
+        if (entry->Enabled)
+            RunCheat(entry);
+    }
+}
+
+}
diff --git a/src/AREngine.h b/src/AREngine.h
new file mode 100644
index 0000000..a78405f
--- /dev/null
+++ b/src/AREngine.h
@@ -0,0 +1,33 @@
+/*
+    Copyright 2016-2020 Arisotura
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef ARENGINE_H
+#define ARENGINE_H
+
+namespace AREngine
+{
+
+bool Init();
+void DeInit();
+void Reset();
+
+void RunCheats();
+
+}
+
+#endif // ARENGINE_H
diff --git a/src/ARM.cpp b/src/ARM.cpp
index b7fe3c7..2d8c807 100644
--- a/src/ARM.cpp
+++ b/src/ARM.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -20,6 +20,7 @@
 #include "NDS.h"
 #include "ARM.h"
 #include "ARMInterpreter.h"
+#include "AREngine.h"
 
 
 // instruction timing notes
@@ -227,6 +228,8 @@ void ARMv5::JumpTo(u32 addr, bool restorecpsr)
         PrefetchAbort();
         return;
     }*/
+
+    NDS::MonitorARM9Jump(addr);
 }
 
 void ARMv4::JumpTo(u32 addr, bool restorecpsr)
@@ -405,6 +408,14 @@ void ARM::TriggerIRQ()
     R_IRQ[2] = oldcpsr;
     R[14] = R[15] + (oldcpsr & 0x20 ? 2 : 0);
     JumpTo(ExceptionBase + 0x18);
+
+    // ARDS cheat support
+    // normally, those work by hijacking the ARM7 VBlank handler
+    if (Num == 1)
+    {
+        if ((NDS::IF[1] & NDS::IE[1]) & (1<<NDS::IRQ_VBlank))
+            AREngine::RunCheats();
+    }
 }
 
 void ARMv5::PrefetchAbort()
diff --git a/src/ARM.h b/src/ARM.h
index a8a7bb3..95c41d4 100644
--- a/src/ARM.h
+++ b/src/ARM.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter.cpp b/src/ARMInterpreter.cpp
index d3f66d8..347fa1e 100644
--- a/src/ARMInterpreter.cpp
+++ b/src/ARMInterpreter.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter.h b/src/ARMInterpreter.h
index 1802bcc..7244238 100644
--- a/src/ARMInterpreter.h
+++ b/src/ARMInterpreter.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter_ALU.cpp b/src/ARMInterpreter_ALU.cpp
index d60d8f8..545667a 100644
--- a/src/ARMInterpreter_ALU.cpp
+++ b/src/ARMInterpreter_ALU.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter_ALU.h b/src/ARMInterpreter_ALU.h
index 0f7fe9b..7f889de 100644
--- a/src/ARMInterpreter_ALU.h
+++ b/src/ARMInterpreter_ALU.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter_Branch.cpp b/src/ARMInterpreter_Branch.cpp
index 6d1cf17..91cf5bb 100644
--- a/src/ARMInterpreter_Branch.cpp
+++ b/src/ARMInterpreter_Branch.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter_Branch.h b/src/ARMInterpreter_Branch.h
index 43347e3..757092f 100644
--- a/src/ARMInterpreter_Branch.h
+++ b/src/ARMInterpreter_Branch.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter_LoadStore.cpp b/src/ARMInterpreter_LoadStore.cpp
index 1d1fc6d..5b05385 100644
--- a/src/ARMInterpreter_LoadStore.cpp
+++ b/src/ARMInterpreter_LoadStore.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARMInterpreter_LoadStore.h b/src/ARMInterpreter_LoadStore.h
index ab69b15..09768a6 100644
--- a/src/ARMInterpreter_LoadStore.h
+++ b/src/ARMInterpreter_LoadStore.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/ARM_InstrTable.h b/src/ARM_InstrTable.h
index 2e4a707..86d7d5a 100644
--- a/src/ARM_InstrTable.h
+++ b/src/ARM_InstrTable.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a4b1c6e..a8093e5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1,6 +1,8 @@
 project(core)
 
 add_library(core STATIC
+	ARCodeList.cpp
+	AREngine.cpp
 	ARM.cpp
 	ARMInterpreter.cpp
 	ARMInterpreter_ALU.cpp
@@ -18,6 +20,7 @@ add_library(core STATIC
 	DSi_NWifi.cpp
 	DSi_SD.cpp
 	DSi_SPI_TSC.cpp
+	GBACart.cpp
 	GPU.cpp
 	GPU2D.cpp
 	GPU3D.cpp
diff --git a/src/CP15.cpp b/src/CP15.cpp
index d412db6..b61cc45 100644
--- a/src/CP15.cpp
+++ b/src/CP15.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/CRC32.cpp b/src/CRC32.cpp
index 5cb47e2..97af721 100644
--- a/src/CRC32.cpp
+++ b/src/CRC32.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/CRC32.h b/src/CRC32.h
index 449457a..a74fa8d 100644
--- a/src/CRC32.h
+++ b/src/CRC32.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/Config.cpp b/src/Config.cpp
index 58aef58..f558ef6 100644
--- a/src/Config.cpp
+++ b/src/Config.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/Config.h b/src/Config.h
index 363df70..84fd57b 100644
--- a/src/Config.h
+++ b/src/Config.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/DMA.cpp b/src/DMA.cpp
index 0826d7a..8e294fc 100644
--- a/src/DMA.cpp
+++ b/src/DMA.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/DMA.h b/src/DMA.h
index 3146ef1..2e7678c 100644
--- a/src/DMA.h
+++ b/src/DMA.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/FIFO.h b/src/FIFO.h
index 213db7a..fe0b2aa 100644
--- a/src/FIFO.h
+++ b/src/FIFO.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GBACart.cpp b/src/GBACart.cpp
new file mode 100644
index 0000000..4d44d3a
--- /dev/null
+++ b/src/GBACart.cpp
@@ -0,0 +1,773 @@
+/*

+    Copyright 2019 Arisotura, Raphaël Zumer

+

+    This file is part of melonDS.

+

+    melonDS is free software: you can redistribute it and/or modify it under

+    the terms of the GNU General Public License as published by the Free

+    Software Foundation, either version 3 of the License, or (at your option)

+    any later version.

+

+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY

+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License along

+    with melonDS. If not, see http://www.gnu.org/licenses/.

+*/

+

+#include <stdio.h>

+#include <string.h>

+#include "GBACart.h"

+#include "CRC32.h"

+#include "Platform.h"

+

+

+namespace GBACart_SRAM

+{

+

+enum SaveType {

+    S_NULL,

+    S_EEPROM4K,

+    S_EEPROM64K,

+    S_SRAM256K,

+    S_FLASH512K,

+    S_FLASH1M

+};

+

+// from DeSmuME

+struct FlashProperties

+{

+    u8 state;

+    u8 cmd;

+    u8 device;

+    u8 manufacturer;

+    u8 bank;

+};

+

+u8* SRAM;

+FILE* SRAMFile;

+u32 SRAMLength;

+SaveType SRAMType;

+FlashProperties SRAMFlashState;

+

+char SRAMPath[1024];

+

+void (*WriteFunc)(u32 addr, u8 val);

+

+

+void Write_Null(u32 addr, u8 val);

+void Write_EEPROM(u32 addr, u8 val);

+void Write_SRAM(u32 addr, u8 val);

+void Write_Flash(u32 addr, u8 val);

+

+

+bool Init()

+{

+    SRAM = NULL;

+    SRAMFile = NULL;

+    return true;

+}

+

+void DeInit()

+{

+    if (SRAMFile) fclose(SRAMFile);

+    if (SRAM) delete[] SRAM;

+}

+

+void Reset()

+{

+    // do nothing, we don't want to clear GBA SRAM on reset

+}

+

+void Eject()

+{

+    if (SRAMFile) fclose(SRAMFile);

+    if (SRAM) delete[] SRAM;

+    SRAM = NULL;

+    SRAMFile = NULL;

+    SRAMLength = 0;

+    SRAMType = S_NULL;

+    SRAMFlashState = {};

+}

+

+void DoSavestate(Savestate* file)

+{

+    file->Section("GBCS"); // Game Boy [Advance] Cart Save

+

+    // logic mostly copied from NDSCart_SRAM

+

+    u32 oldlen = SRAMLength;

+

+    file->Var32(&SRAMLength);

+

+    if (SRAMLength != oldlen)

+    {

+        // reallocate save memory

+        if (oldlen) delete[] SRAM;

+        if (SRAMLength) SRAM = new u8[SRAMLength];

+    }

+    if (SRAMLength)

+    {

+        // fill save memory if data is present

+        file->VarArray(SRAM, SRAMLength);

+    }

+    else

+    {

+        // no save data, clear the current state

+        SRAMType = SaveType::S_NULL;

+        if (SRAMFile) fclose(SRAMFile);

+        SRAM = NULL;

+        SRAMFile = NULL;

+        return;

+    }

+

+    // persist some extra state info

+    file->Var8(&SRAMFlashState.bank);

+    file->Var8(&SRAMFlashState.cmd);

+    file->Var8(&SRAMFlashState.device);

+    file->Var8(&SRAMFlashState.manufacturer);

+    file->Var8(&SRAMFlashState.state);

+

+    file->Var8((u8*)&SRAMType);

+}

+

+void LoadSave(const char* path)

+{

+    if (SRAM) delete[] SRAM;

+

+    strncpy(SRAMPath, path, 1023);

+    SRAMPath[1023] = '\0';

+    SRAMLength = 0;

+

+    FILE* f = Platform::OpenFile(SRAMPath, "r+b");

+    if (f)

+    {

+        fseek(f, 0, SEEK_END);

+        SRAMLength = (u32)ftell(f);

+        SRAM = new u8[SRAMLength];

+

+        fseek(f, 0, SEEK_SET);

+        fread(SRAM, SRAMLength, 1, f);

+

+        SRAMFile = f;

+    }

+

+    switch (SRAMLength)

+    {

+    case 512:

+        SRAMType = S_EEPROM4K;

+        WriteFunc = Write_EEPROM;

+        break;

+    case 8192:

+        SRAMType = S_EEPROM64K;

+        WriteFunc = Write_EEPROM;

+        break;

+    case 32768:

+        SRAMType = S_SRAM256K;

+        WriteFunc = Write_SRAM;

+        break;

+    case 65536:

+        SRAMType = S_FLASH512K;

+        WriteFunc = Write_Flash;

+        break;

+    case 128*1024:

+        SRAMType = S_FLASH1M;

+        WriteFunc = Write_Flash;

+        break;

+    default:

+        printf("!! BAD SAVE LENGTH %d\n", SRAMLength);

+    case 0:

+        SRAMType = S_NULL;

+        WriteFunc = Write_Null;

+        break;

+    }

+

+    if (SRAMType == S_FLASH512K)

+    {

+        // Panasonic 64K chip

+        SRAMFlashState.device = 0x1B;

+        SRAMFlashState.manufacturer = 0x32;

+    }

+    else if (SRAMType == S_FLASH1M)

+    {

+        // Sanyo 128K chip

+        SRAMFlashState.device = 0x13;

+        SRAMFlashState.manufacturer = 0x62;

+    }

+}

+

+void RelocateSave(const char* path, bool write)

+{

+    if (!write)

+    {

+        LoadSave(path); // lazy

+        return;

+    }

+

+    strncpy(SRAMPath, path, 1023);

+    SRAMPath[1023] = '\0';

+

+    FILE *f = Platform::OpenFile(path, "r+b");

+    if (!f)

+    {

+        printf("GBACart_SRAM::RelocateSave: failed to create new file. fuck\n");

+        return;

+    }

+

+    SRAMFile = f;

+    fwrite(SRAM, SRAMLength, 1, SRAMFile);

+}

+

+// mostly ported from DeSmuME

+u8 Read_Flash(u32 addr)

+{

+    if (SRAMFlashState.cmd == 0) // no cmd

+    {

+        return *(u8*)&SRAM[addr + 0x10000 * SRAMFlashState.bank];

+    }

+

+    switch (SRAMFlashState.cmd)

+    {

+        case 0x90: // chip ID

+            if (addr == 0x0000) return SRAMFlashState.manufacturer;

+            if (addr == 0x0001) return SRAMFlashState.device;

+            break;

+        case 0xF0: // terminate command (TODO: break if non-Macronix chip and not at the end of an ID call?)

+            SRAMFlashState.state = 0;

+            SRAMFlashState.cmd = 0;

+            break;

+        case 0xA0: // write command

+            break; // ignore here, handled in Write_Flash()

+        case 0xB0: // bank switching (128K only)

+            break; // ignore here, handled in Write_Flash()

+        default:

+            printf("GBACart_SRAM::Read_Flash: unknown command 0x%02X @ 0x%04X\n", SRAMFlashState.cmd, addr);

+            break;

+    }

+

+    return 0xFF;

+}

+

+void Write_Null(u32 addr, u8 val) {}

+

+void Write_EEPROM(u32 addr, u8 val)

+{

+    // TODO: could be used in homebrew?

+}

+

+// mostly ported from DeSmuME

+void Write_Flash(u32 addr, u8 val)

+{

+    switch (SRAMFlashState.state)

+    {

+        case 0x00:

+            if (addr == 0x5555)

+            {

+                if (val == 0xF0)

+                {

+                    // reset

+                    SRAMFlashState.state = 0;

+                    SRAMFlashState.cmd = 0;

+                    return;

+                }

+                else if (val == 0xAA)

+                {

+                    SRAMFlashState.state = 1;

+                    return;

+                }

+            }

+            if (addr == 0x0000)

+            {

+                if (SRAMFlashState.cmd == 0xB0)

+                {

+                    // bank switching

+                    SRAMFlashState.bank = val;

+                    SRAMFlashState.cmd = 0;

+                    return;

+                }

+            }

+            break;

+        case 0x01:

+            if (addr == 0x2AAA && val == 0x55)

+            {

+                SRAMFlashState.state = 2;

+                return;

+            }

+            SRAMFlashState.state = 0;

+            break;

+        case 0x02:

+            if (addr == 0x5555)

+            {

+                // send command

+                switch (val)

+                {

+                    case 0x80: // erase

+                        SRAMFlashState.state = 0x80;

+                        break;

+                    case 0x90: // chip ID

+                        SRAMFlashState.state = 0x90;

+                        break;

+                    case 0xA0: // write

+                        SRAMFlashState.state = 0;

+                        break;

+                    default:

+                        SRAMFlashState.state = 0;

+                        break;

+                }

+

+                SRAMFlashState.cmd = val;

+                return;

+            }

+            SRAMFlashState.state = 0;

+            break;

+        // erase

+        case 0x80:

+            if (addr == 0x5555 && val == 0xAA)

+            {

+                SRAMFlashState.state = 0x81;

+                return;

+            }

+            SRAMFlashState.state = 0;

+            break;

+        case 0x81:

+            if (addr == 0x2AAA && val == 0x55)

+            {

+                SRAMFlashState.state = 0x82;

+                return;

+            }

+            SRAMFlashState.state = 0;

+            break;

+        case 0x82:

+            if (val == 0x30)

+            {

+                u32 start_addr = addr + 0x10000 * SRAMFlashState.bank;

+                memset((u8*)&SRAM[start_addr], 0xFF, 0x1000);

+

+                if (SRAMFile)

+                {

+                    fseek(SRAMFile, start_addr, SEEK_SET);

+                    fwrite((u8*)&SRAM[start_addr], 1, 0x1000, SRAMFile);

+                }

+            }

+            SRAMFlashState.state = 0;

+            SRAMFlashState.cmd = 0;

+            return;

+        // chip ID

+        case 0x90:

+            if (addr == 0x5555 && val == 0xAA)

+            {

+                SRAMFlashState.state = 0x91;

+                return;

+            }

+            SRAMFlashState.state = 0;

+            break;

+        case 0x91:

+            if (addr == 0x2AAA && val == 0x55)

+            {

+                SRAMFlashState.state = 0x92;

+                return;

+            }

+            SRAMFlashState.state = 0;

+            break;

+        case 0x92:

+            SRAMFlashState.state = 0;

+            SRAMFlashState.cmd = 0;

+            return;

+        default:

+            break;

+    }

+

+    if (SRAMFlashState.cmd == 0xA0) // write

+    {

+        Write_SRAM(addr + 0x10000 * SRAMFlashState.bank, val);

+        SRAMFlashState.state = 0;

+        SRAMFlashState.cmd = 0;

+        return;

+    }

+

+    printf("GBACart_SRAM::Write_Flash: unknown write 0x%02X @ 0x%04X (state: 0x%02X)\n",

+        val, addr, SRAMFlashState.state);

+}

+

+void Write_SRAM(u32 addr, u8 val)

+{

+    u8 prev = *(u8*)&SRAM[addr];

+

+    if (prev != val)

+    {

+        *(u8*)&SRAM[addr] = val;

+

+        if (SRAMFile)

+        {

+            fseek(SRAMFile, addr, SEEK_SET);

+            fwrite((u8*)&SRAM[addr], 1, 1, SRAMFile);

+        }

+    }

+}

+

+u8 Read8(u32 addr)

+{

+    if (SRAMType == S_NULL)

+    {

+        return 0xFF;

+    }

+

+    if (SRAMType == S_FLASH512K || SRAMType == S_FLASH1M)

+    {

+        return Read_Flash(addr);

+    }

+

+    return *(u8*)&SRAM[addr];

+}

+

+u16 Read16(u32 addr)

+{

+    if (SRAMType == S_NULL)

+    {

+        return 0xFFFF;

+    }

+

+    if (SRAMType == S_FLASH512K || SRAMType == S_FLASH1M)

+    {

+        u16 val = Read_Flash(addr + 0) |

+            (Read_Flash(addr + 1) << 8);

+        return val;

+    }

+

+    return *(u16*)&SRAM[addr];

+}

+

+u32 Read32(u32 addr)

+{

+    if (SRAMType == S_NULL)

+    {

+        return 0xFFFFFFFF;

+    }

+

+    if (SRAMType == S_FLASH512K || SRAMType == S_FLASH1M)

+    {

+        u32 val = Read_Flash(addr + 0) |

+            (Read_Flash(addr + 1) << 8) |

+            (Read_Flash(addr + 2) << 16) |

+            (Read_Flash(addr + 3) << 24);

+        return val;

+    }

+

+    return *(u32*)&SRAM[addr];

+}

+

+void Write8(u32 addr, u8 val)

+{

+    u8 prev = *(u8*)&SRAM[addr];

+

+    WriteFunc(addr, val);

+}

+

+void Write16(u32 addr, u16 val)

+{

+    u16 prev = *(u16*)&SRAM[addr];

+

+    WriteFunc(addr + 0, val & 0xFF);

+    WriteFunc(addr + 1, val >> 8 & 0xFF);

+}

+

+void Write32(u32 addr, u32 val)

+{

+    u32 prev = *(u32*)&SRAM[addr];

+

+    WriteFunc(addr + 0, val & 0xFF);

+    WriteFunc(addr + 1, val >> 8 & 0xFF);

+    WriteFunc(addr + 2, val >> 16 & 0xFF);

+    WriteFunc(addr + 3, val >> 24 & 0xFF);

+}

+

+}

+

+

+namespace GBACart

+{

+

+const char SOLAR_SENSOR_GAMECODES[10][5] =

+{

+    "U3IJ", // Bokura no Taiyou - Taiyou Action RPG (Japan)

+    "U3IE", // Boktai - The Sun Is in Your Hand (USA)

+    "U3IP", // Boktai - The Sun Is in Your Hand (Europe)

+    "U32J", // Zoku Bokura no Taiyou - Taiyou Shounen Django (Japan)

+    "U32E", // Boktai 2 - Solar Boy Django (USA)

+    "U32P", // Boktai 2 - Solar Boy Django (Europe)

+    "U33J", // Shin Bokura no Taiyou - Gyakushuu no Sabata (Japan)

+    "A3IJ"  // Boktai - The Sun Is in Your Hand (USA) (Sample)

+};

+

+

+bool CartInserted;

+bool HasSolarSensor;

+u8* CartROM;

+u32 CartROMSize;

+u32 CartCRC;

+u32 CartID;

+GPIO CartGPIO; // overridden GPIO parameters

+

+

+bool Init()

+{

+    if (!GBACart_SRAM::Init()) return false;

+

+    CartROM = NULL;

+

+    return true;

+}

+

+void DeInit()

+{

+    if (CartROM) delete[] CartROM;

+

+    GBACart_SRAM::DeInit();

+}

+

+void Reset()

+{

+    // Do not reset cartridge ROM.

+    // Prefer keeping the inserted cartridge on reset.

+    // This allows resetting a DS game without losing GBA state,

+    // and resetting to firmware without the slot being emptied.

+    // The Stop function will clear the cartridge state via Eject().

+

+    GBACart_SRAM::Reset();

+    GBACart_SolarSensor::Reset();

+}

+

+void Eject()

+{

+    if (CartROM) delete[] CartROM;

+

+    CartInserted = false;

+    HasSolarSensor = false;

+    CartROM = NULL;

+    CartROMSize = 0;

+    CartCRC = NULL;

+    CartID = NULL;

+    CartGPIO = {};

+

+    GBACart_SRAM::Eject();

+    Reset();

+}

+

+void DoSavestate(Savestate* file)

+{

+    file->Section("GBAC"); // Game Boy Advance Cartridge

+

+    // logic mostly copied from NDSCart

+

+    // first we need to reload the cart itself,

+    // since unlike with DS, it's not loaded in advance

+

+    file->Var32(&CartROMSize);

+    if (!CartROMSize) // no GBA cartridge state? nothing to do here

+    {

+        // do eject the cartridge if something is inserted

+        Eject();

+        return;

+    }

+

+    u32 oldCRC = CartCRC;

+    file->Var32(&CartCRC);

+

+    if (CartCRC != oldCRC)

+    {

+        // delete and reallocate ROM so that it is zero-padded to its full length

+        if (CartROM) delete[] CartROM;

+        CartROM = new u8[CartROMSize];

+

+        // clear the SRAM file handle; writes will not be committed

+        if (GBACart_SRAM::SRAMFile)

+        {

+            fclose(GBACart_SRAM::SRAMFile);

+            GBACart_SRAM::SRAMFile = NULL;

+        }

+    }

+

+    // only save/load the cartridge header

+    //

+    // GBA connectivity on DS mainly involves identifying the title currently

+    // inserted, reading save data, and issuing commands intercepted here

+    // (e.g. solar sensor signals). we don't know of any case where GBA ROM is

+    // read directly from DS software. therefore, it is more practical, both

+    // from the development and user experience perspectives, to avoid dealing

+    // with file dependencies, and store a small portion of ROM data that should

+    // satisfy the needs of all known software that reads from the GBA slot.

+    //

+    // note: in case of a state load, only the cartridge header is restored, but

+    // the rest of the ROM data is only cleared (zero-initialized) if the CRC

+    // differs. Therefore, loading the GBA cartridge associated with the save state

+    // in advance will maintain access to the full ROM contents.

+    file->VarArray(CartROM, 192);

+

+    CartInserted = true; // known, because CartROMSize > 0

+    file->Var32(&CartCRC);

+    file->Var32(&CartID);

+

+    file->Var8((u8*)&HasSolarSensor);

+

+    file->Var16(&CartGPIO.control);

+    file->Var16(&CartGPIO.data);

+    file->Var16(&CartGPIO.direction);

+

+    // now do the rest

+

+    GBACart_SRAM::DoSavestate(file);

+    if (HasSolarSensor) GBACart_SolarSensor::DoSavestate(file);

+}

+

+bool LoadROM(const char* path, const char* sram)

+{

+    FILE* f = Platform::OpenFile(path, "rb");

+    if (!f)

+    {

+        return false;

+    }

+

+    if (CartInserted)

+    {

+        Reset();

+    }

+

+    fseek(f, 0, SEEK_END);

+    u32 len = (u32)ftell(f);

+

+    CartROMSize = 0x200;

+    while (CartROMSize < len)

+        CartROMSize <<= 1;

+

+    char gamecode[5] = { '\0' };

+    fseek(f, 0xAC, SEEK_SET);

+    fread(&gamecode, 1, 4, f);

+    printf("Game code: %s\n", gamecode);

+

+    for (int i = 0; i < sizeof(SOLAR_SENSOR_GAMECODES)/sizeof(SOLAR_SENSOR_GAMECODES[0]); i++)

+    {

+        if (strcmp(gamecode, SOLAR_SENSOR_GAMECODES[i]) == 0) HasSolarSensor = true;

+    }

+

+    if (HasSolarSensor)

+    {

+        printf("GBA solar sensor support detected!\n");

+    }

+

+    CartROM = new u8[CartROMSize];

+    memset(CartROM, 0, CartROMSize);

+    fseek(f, 0, SEEK_SET);

+    fread(CartROM, 1, len, f);

+

+    fclose(f);

+

+    CartCRC = CRC32(CartROM, CartROMSize);

+    printf("ROM CRC32: %08X\n", CartCRC);

+

+    CartInserted = true;

+

+    // save

+    printf("Save file: %s\n", sram);

+    GBACart_SRAM::LoadSave(sram);

+

+    return true;

+}

+

+void RelocateSave(const char* path, bool write)

+{

+    // derp herp

+    GBACart_SRAM::RelocateSave(path, write);

+}

+

+// referenced from mGBA

+void WriteGPIO(u32 addr, u16 val)

+{

+    switch (addr)

+    {

+        case 0xC4:

+            CartGPIO.data &= ~CartGPIO.direction;

+            CartGPIO.data |= val & CartGPIO.direction;

+            if (HasSolarSensor) GBACart_SolarSensor::Process(&CartGPIO);

+            break;

+        case 0xC6:

+            CartGPIO.direction = val;

+            break;

+        case 0xC8:

+            CartGPIO.control = val;

+            break;

+        default:

+            printf("Unknown GBA GPIO write 0x%02X @ 0x%04X\n", val, addr);

+    }

+

+    // write the GPIO values in the ROM (if writable)

+    if (CartGPIO.control & 1)

+    {

+        *(u16*)&CartROM[0xC4] = CartGPIO.data;

+        *(u16*)&CartROM[0xC6] = CartGPIO.direction;

+        *(u16*)&CartROM[0xC8] = CartGPIO.control;

+    }

+    else

+    {

+        // GBATEK: "in write-only mode, reads return 00h (or [possibly] other data (...))"

+        // ambiguous, but mGBA sets ROM to 00h when switching to write-only, so do the same

+        *(u16*)&CartROM[0xC4] = 0;

+        *(u16*)&CartROM[0xC6] = 0;

+        *(u16*)&CartROM[0xC8] = 0;

+    }

+}

+

+}

+

+

+namespace GBACart_SolarSensor

+{

+

+bool LightEdge;

+u8 LightCounter;

+u8 LightSample;

+u8 LightLevel; // 0-10 range

+

+// levels from mGBA

+const int GBA_LUX_LEVELS[11] = { 0, 5, 11, 18, 27, 42, 62, 84, 109, 139, 183 };

+#define LIGHT_VALUE (0xFF - (0x16 + GBA_LUX_LEVELS[LightLevel]))

+

+

+void Reset()

+{

+    LightEdge = false;

+    LightCounter = 0;

+    LightSample = 0xFF;

+    LightLevel = 0;

+}

+

+void DoSavestate(Savestate* file)

+{

+    file->Var8((u8*)&LightEdge);

+    file->Var8(&LightCounter);

+    file->Var8(&LightSample);

+    file->Var8(&LightLevel);

+}

+

+void Process(GBACart::GPIO* gpio)

+{

+    if (gpio->data & 4) return; // Boktai chip select

+    if (gpio->data & 2) // Reset

+    {

+        u8 prev = LightSample;

+        LightCounter = 0;

+        LightSample = LIGHT_VALUE;

+        printf("Solar sensor reset (sample: 0x%02X -> 0x%02X)\n", prev, LightSample);

+    }

+    if (gpio->data & 1 && LightEdge) LightCounter++;

+

+    LightEdge = !(gpio->data & 1);

+

+    bool sendBit = LightCounter >= LightSample;

+    if (gpio->control & 1)

+    {

+        gpio->data = (gpio->data & gpio->direction) | ((sendBit << 3) & ~gpio->direction & 0xF);

+    }

+}

+

+}

diff --git a/src/GBACart.h b/src/GBACart.h
new file mode 100644
index 0000000..96a05b8
--- /dev/null
+++ b/src/GBACart.h
@@ -0,0 +1,87 @@
+/*

+    Copyright 2019 Arisotura, Raphaël Zumer

+

+    This file is part of melonDS.

+

+    melonDS is free software: you can redistribute it and/or modify it under

+    the terms of the GNU General Public License as published by the Free

+    Software Foundation, either version 3 of the License, or (at your option)

+    any later version.

+

+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY

+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License along

+    with melonDS. If not, see http://www.gnu.org/licenses/.

+*/

+

+#ifndef GBACART_H

+#define GBACART_H

+

+#include "types.h"

+#include "Savestate.h"

+

+

+namespace GBACart_SRAM

+{

+

+extern u8* SRAM;

+extern u32 SRAMLength;

+

+void Reset();

+void DoSavestate(Savestate* file);

+

+u8 Read8(u32 addr);

+u16 Read16(u32 addr);

+u32 Read32(u32 addr);

+

+void Write8(u32 addr, u8 val);

+void Write16(u32 addr, u16 val);

+void Write32(u32 addr, u32 val);

+

+}

+

+

+namespace GBACart

+{

+

+struct GPIO

+{

+    u16 data;

+    u16 direction;

+    u16 control;

+};

+

+extern bool CartInserted;

+extern bool HasSolarSensor;

+extern u8* CartROM;

+extern u32 CartROMSize;

+extern u32 CartCRC;

+

+bool Init();

+void DeInit();

+void Reset();

+void Eject();

+

+void DoSavestate(Savestate* file);

+bool LoadROM(const char* path, const char* sram);

+void RelocateSave(const char* path, bool write);

+

+void WriteGPIO(u32 addr, u16 val);

+

+}

+

+

+namespace GBACart_SolarSensor

+{

+

+extern u8 LightLevel;

+

+void Reset();

+void DoSavestate(Savestate* file);

+void Process(GBACart::GPIO* gpio);

+

+}

+

+#endif // GBACART_H

diff --git a/src/GPU.cpp b/src/GPU.cpp
index 13f2727..01fde91 100644
--- a/src/GPU.cpp
+++ b/src/GPU.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU.h b/src/GPU.h
index 7e7a9d1..661a7d9 100644
--- a/src/GPU.h
+++ b/src/GPU.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU2D.cpp b/src/GPU2D.cpp
index 30a6d45..1c6cf0c 100644
--- a/src/GPU2D.cpp
+++ b/src/GPU2D.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU2D.h b/src/GPU2D.h
index 6675ce7..c4bd2f9 100644
--- a/src/GPU2D.h
+++ b/src/GPU2D.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU3D.cpp b/src/GPU3D.cpp
index 1c3fbee..4f146ae 100644
--- a/src/GPU3D.cpp
+++ b/src/GPU3D.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -181,6 +181,8 @@ u8 RenderFogDensityTable[34];
 
 u32 RenderClearAttr1, RenderClearAttr2;
 
+u32 ZeroDotWLimit;
+
 u32 GXStat;
 
 u32 ExecParams[32];
@@ -332,6 +334,8 @@ void Reset()
     DispCnt = 0;
     AlphaRef = 0;
 
+    ZeroDotWLimit = 0; // CHECKME
+
     GXStat = 0;
 
     memset(ExecParams, 0, 32*4);
@@ -409,6 +413,8 @@ void DoSavestate(Savestate* file)
     file->Var32(&DispCnt);
     file->Var8(&AlphaRef);
 
+    file->Var32(&ZeroDotWLimit);
+
     file->Var32(&GXStat);
 
     file->VarArray(ExecParams, 32*4);
@@ -569,27 +575,12 @@ void DoSavestate(Savestate* file)
 
     // probably not worth storing the vblank-latched Renderxxxxxx variables
 
-    if (file->IsAtleastVersion(2, 1))
-    {
-        // command stall queue, only in version 2.1 and up
-        CmdStallQueue->DoSavestate(file);
-        file->Var32((u32*)&VertexPipeline);
-        file->Var32((u32*)&NormalPipeline);
-        file->Var32((u32*)&PolygonPipeline);
-        file->Var32((u32*)&VertexSlotCounter);
-        file->Var32(&VertexSlotsFree);
-    }
-    else
-    {
-        // for version 2.0, just clear it. not having it doesn't matter
-        // if this comes from older melonDS revisions.
-        CmdStallQueue->Clear();
-        VertexPipeline = 0;
-        NormalPipeline = 0;
-        PolygonPipeline = 0;
-        VertexSlotCounter = 0;
-        VertexSlotsFree = 1;
-    }
+    CmdStallQueue->DoSavestate(file);
+    file->Var32((u32*)&VertexPipeline);
+    file->Var32((u32*)&NormalPipeline);
+    file->Var32((u32*)&PolygonPipeline);
+    file->Var32((u32*)&VertexSlotCounter);
+    file->Var32(&VertexSlotsFree);
 
     if (!file->Saving)
     {
@@ -888,7 +879,7 @@ void StallPolygonPipeline(s32 delay, s32 nonstalldelay)
 
 
 template<int comp, s32 plane, bool attribs>
-void ClipSegment(Vertex* outbuf, Vertex* vout, Vertex* vin)
+void ClipSegment(Vertex* outbuf, Vertex* vin, Vertex* vout)
 {
     s64 factor_num = vin->Position[3] - (plane*vin->Position[comp]);
     s32 factor_den = factor_num - (vout->Position[3] - (plane*vout->Position[comp]));
@@ -1170,6 +1161,104 @@ void SubmitPolygon()
         return;
     }
 
+    // reject the polygon if it's not going to fit in polygon/vertex RAM
+
+    if (NumPolygons >= 2048 || NumVertices+nverts > 6144)
+    {
+        LastStripPolygon = NULL;
+        DispCnt |= (1<<13);
+        return;
+    }
+
+    // compute screen coordinates
+
+    for (int i = clipstart; i < nverts; i++)
+    {
+        Vertex* vtx = &clippedvertices[i];
+
+        // W is truncated to 24 bits at this point
+        // if this W is zero, the polygon isn't rendered
+        vtx->Position[3] &= 0x00FFFFFF;
+
+        // viewport transform
+        // note: the DS performs these divisions using a 32-bit divider
+        // thus, if W is greater than 0xFFFF, some precision is sacrificed
+        // to make the numbers fit into the divider
+        u32 posX, posY;
+        u32 w = vtx->Position[3];
+        if (w == 0)
+        {
+            posX = 0;
+            posY = 0;
+        }
+        else
+        {
+            posX = vtx->Position[0] + w;
+            posY = -vtx->Position[1] + w;
+            u32 den = w;
+
+            if (w > 0xFFFF)
+            {
+                posX >>= 1;
+                posY >>= 1;
+                den  >>= 1;
+            }
+
+            den <<= 1;
+            posX = ((posX * Viewport[4]) / den) + Viewport[0];
+            posY = ((posY * Viewport[5]) / den) + Viewport[3];
+        }
+
+        vtx->FinalPosition[0] = posX & 0x1FF;
+        vtx->FinalPosition[1] = posY & 0xFF;
+
+        // hi-res positions
+        // to consider: only do this when using the GL renderer? apply the aforementioned quirk to this?
+        if (w != 0)
+        {
+            posX = ((((s64)(vtx->Position[0] + w) * Viewport[4]) << 4) / (((s64)w) << 1)) + (Viewport[0] << 4);
+            posY = ((((s64)(-vtx->Position[1] + w) * Viewport[5]) << 4) / (((s64)w) << 1)) + (Viewport[3] << 4);
+
+            vtx->HiresPosition[0] = posX & 0x1FFF;
+            vtx->HiresPosition[1] = posY & 0xFFF;
+        }
+    }
+
+    // zero-dot W check:
+    // * if the polygon's vertices all have the same screen coordinates, it is considered to be zero-dot
+    // * if all the vertices have a W greater than the threshold defined in register 0x04000610,
+    //   the polygon is rejected, unless bit13 in the polygon attributes is set
+
+    if (!(CurPolygonAttr & (1<<13)))
+    {
+        bool zerodot = true;
+        bool allbehind = true;
+
+        for (int i = 0; i < nverts; i++)
+        {
+            Vertex* vtx = &clippedvertices[i];
+
+            if (vtx->FinalPosition[0] != clippedvertices[0].FinalPosition[0] ||
+                vtx->FinalPosition[1] != clippedvertices[0].FinalPosition[1])
+            {
+                zerodot = false;
+                break;
+            }
+
+            if (vtx->Position[3] <= ZeroDotWLimit)
+            {
+                allbehind = false;
+                break;
+            }
+        }
+
+        if (zerodot && allbehind)
+        {
+            LastStripPolygon = NULL;
+            return;
+        }
+    }
+
     // build the actual polygon
 
     if (nverts == 4)
@@ -1187,13 +1276,6 @@ void SubmitPolygon()
         else                   VertexSlotsFree = 0b1110;
     }
 
-    if (NumPolygons >= 2048 || NumVertices+nverts > 6144)
-    {
-        LastStripPolygon = NULL;
-        DispCnt |= (1<<13);
-        return;
-    }
-
     Polygon* poly = &CurPolygonRAM[NumPolygons++];
     poly->NumVertices = 0;
 
@@ -1248,37 +1330,6 @@ void SubmitPolygon()
         NumVertices++;
         poly->NumVertices++;
 
-        // W is truncated to 24 bits at this point
-        // if this W is zero, the polygon isn't rendered
-        vtx->Position[3] &= 0x00FFFFFF;
-
-        // viewport transform
-        s32 posX, posY;
-        s32 w = vtx->Position[3];
-        if (w == 0)
-        {
-            posX = 0;
-            posY = 0;
-        }
-        else
-        {
-            posX = (((s64)(vtx->Position[0] + w) * Viewport[4]) / (((s64)w) << 1)) + Viewport[0];
-            posY = (((s64)(-vtx->Position[1] + w) * Viewport[5]) / (((s64)w) << 1)) + Viewport[3];
-        }
-
-        vtx->FinalPosition[0] = posX & 0x1FF;
-        vtx->FinalPosition[1] = posY & 0xFF;
-
-        // hi-res positions
-        if (w != 0)
-        {
-            posX = ((((s64)(vtx->Position[0] + w) * Viewport[4]) << 4) / (((s64)w) << 1)) + (Viewport[0] << 4);
-            posY = ((((s64)(-vtx->Position[1] + w) * Viewport[5]) << 4) / (((s64)w) << 1)) + (Viewport[3] << 4);
-
-            vtx->HiresPosition[0] = posX & 0x1FFF;
-            vtx->HiresPosition[1] = posY & 0xFFF;
-        }
-
         vtx->FinalColor[0] = vtx->Color[0] >> 12;
         if (vtx->FinalColor[0]) vtx->FinalColor[0] = ((vtx->FinalColor[0] << 4) + 0xF);
         vtx->FinalColor[1] = vtx->Color[1] >> 12;
@@ -2716,12 +2767,24 @@ void Write8(u32 addr, u8 val)
         return;
     }
 
+    if (addr >= 0x04000330 && addr < 0x04000340)
+    {
+        ((u8*)EdgeTable)[addr - 0x04000330] = val;
+        return;
+    }
+
     if (addr >= 0x04000360 && addr < 0x04000380)
     {
         FogDensityTable[addr - 0x04000360] = val & 0x7F;
         return;
     }
 
+    if (addr >= 0x04000380 && addr < 0x040003C0)
+    {
+        ((u8*)ToonTable)[addr - 0x04000380] = val;
+        return;
+    }
+
     printf("unknown GPU3D write8 %08X %02X\n", addr, val);
 }
 
@@ -2782,6 +2845,11 @@ void Write16(u32 addr, u16 val)
         GXStat |= (val << 16);
         CheckFIFOIRQ();
         return;
+
+    case 0x04000610:
+        val &= 0x7FFF;
+        ZeroDotWLimit = (val * 0x200) + 0x1FF;
+        return;
     }
 
     if (addr >= 0x04000330 && addr < 0x04000340)
@@ -2853,6 +2921,11 @@ void Write32(u32 addr, u32 val)
         GXStat |= val;
         CheckFIFOIRQ();
         return;
+
+    case 0x04000610:
+        val &= 0x7FFF;
+        ZeroDotWLimit = (val * 0x200) + 0x1FF;
+        return;
     }
 
     if (addr >= 0x04000400 && addr < 0x04000440)
diff --git a/src/GPU3D.h b/src/GPU3D.h
index fd52488..1fd3383 100644
--- a/src/GPU3D.h
+++ b/src/GPU3D.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU3D_OpenGL.cpp b/src/GPU3D_OpenGL.cpp
index 6abb1ab..b1bcaa1 100644
--- a/src/GPU3D_OpenGL.cpp
+++ b/src/GPU3D_OpenGL.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU3D_OpenGL_shaders.h b/src/GPU3D_OpenGL_shaders.h
index 2545ee0..5722ca5 100644
--- a/src/GPU3D_OpenGL_shaders.h
+++ b/src/GPU3D_OpenGL_shaders.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/GPU3D_Soft.cpp b/src/GPU3D_Soft.cpp
index 193d198..8397898 100644
--- a/src/GPU3D_Soft.cpp
+++ b/src/GPU3D_Soft.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/NDS.cpp b/src/NDS.cpp
index 18e2ae1..e04df01 100644
--- a/src/NDS.cpp
+++ b/src/NDS.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -22,6 +22,7 @@
 #include "NDS.h"
 #include "ARM.h"
 #include "NDSCart.h"
+#include "GBACart.h"
 #include "DMA.h"
 #include "FIFO.h"
 #include "GPU.h"
@@ -29,6 +30,7 @@
 #include "SPI.h"
 #include "RTC.h"
 #include "Wifi.h"
+#include "AREngine.h"
 #include "Platform.h"
 
 #include "DSi.h"
@@ -103,6 +105,7 @@ u8 ARM7WRAM[0x10000];
 
 u16 ExMemCnt[2];
 
+// TODO: these belong in NDSCart!
 u8 ROMSeed0[2*8];
 u8 ROMSeed1[2*8];
 
@@ -148,6 +151,8 @@ u16 RCnt;
 
 bool Running;
 
+bool RunningGame;
+
 
 void DivDone(u32 param);
 void SqrtDone(u32 param);
@@ -174,6 +179,7 @@ bool Init()
     IPCFIFO7 = new FIFO<u32>(16);
 
     if (!NDSCart::Init()) return false;
+    if (!GBACart::Init()) return false;
     if (!GPU::Init()) return false;
     if (!SPU::Init()) return false;
     if (!SPI::Init()) return false;
@@ -182,6 +188,8 @@ bool Init()
 
     if (!DSi::Init()) return false;
 
+    if (!AREngine::Init()) return false;
+
     return true;
 }
 
@@ -197,6 +205,7 @@ void DeInit()
     delete IPCFIFO7;
 
     NDSCart::DeInit();
+    GBACart::DeInit();
     GPU::DeInit();
     SPU::DeInit();
     SPI::DeInit();
@@ -204,6 +213,8 @@ void DeInit()
     Wifi::DeInit();
 
     DSi::DeInit();
+
+    AREngine::DeInit();
 }
 
 
@@ -320,7 +331,24 @@ void SetupDirectBoot()
 
     MapSharedWRAM(3);
 
-    for (u32 i = 0; i < bootparams[3]; i+=4)
+    u32 arm9start = 0;
+
+    // load the ARM9 secure area
+    if (bootparams[0] >= 0x4000 && bootparams[0] < 0x8000)
+    {
+        u8 securearea[0x800];
+        NDSCart::DecryptSecureArea(securearea);
+
+        for (u32 i = 0; i < 0x800; i+=4)
+        {
+            ARM9Write32(bootparams[2]+i, *(u32*)&securearea[i]);
+            arm9start += 4;
+        }
+    }
+
+    // CHECKME: firmware seems to load this in 0x200 byte chunks
+
+    for (u32 i = arm9start; i < bootparams[3]; i+=4)
     {
         u32 tmp = *(u32*)&NDSCart::CartROM[bootparams[0]+i];
         ARM9Write32(bootparams[2]+i, tmp);
@@ -398,6 +426,7 @@ void Reset()
     FILE* f;
     u32 i;
 
+    RunningGame = false;
     LastSysClockCycles = 0;
 
     memset(ARM9BIOS, 0, 0x1000);
@@ -523,6 +552,7 @@ void Reset()
     RCnt = 0;
 
     NDSCart::Reset();
+    GBACart::Reset();
     GPU::Reset();
     SPU::Reset();
     SPI::Reset();
@@ -531,6 +561,8 @@ void Reset()
 
     DSi::Reset();
     KeyInput &= ~(1 << (16+6)); // TODO
+
+    AREngine::Reset();
 }
 
 void Stop()
@@ -700,21 +732,16 @@ bool DoSavestate(Savestate* file)
     file->Var16(&KeyCnt);
     file->Var16(&RCnt);
 
+    file->Var8(&WRAMCnt);
 
-    for (int i = 0; i < 8; i++)
-        DMAs[i]->DoSavestate(file);
-
-    file->Var8(&WRAMCnt); // FIXME!!!!!
+    file->Var32((u32*)&RunningGame);
 
     if (!file->Saving)
     {
         // 'dept of redundancy dept'
         // but we do need to update the mappings
         MapSharedWRAM(WRAMCnt);
-    }
 
-    if (!file->Saving)
-    {
         InitTimings();
         SetGBASlotTimings();
 
@@ -723,10 +750,14 @@ bool DoSavestate(Savestate* file)
         SetWifiWaitCnt(tmp); // force timing table update
     }
 
+    for (int i = 0; i < 8; i++)
+        DMAs[i]->DoSavestate(file);
+
     ARM9->DoSavestate(file);
     ARM7->DoSavestate(file);
 
     NDSCart::DoSavestate(file);
+    GBACart::DoSavestate(file);
     GPU::DoSavestate(file);
     SPU::DoSavestate(file);
     SPI::DoSavestate(file);
@@ -755,6 +786,19 @@ bool LoadROM(const char* path, const char* sram, bool direct)
     }
 }
 
+bool LoadGBAROM(const char* path, const char* sram)
+{
+    if (GBACart::LoadROM(path, sram))
+    {
+        return true;
+    }
+    else
+    {
+        printf("Failed to load ROM %s\n", path);
+        return false;
+    }
+}
+
 void LoadBIOS()
 {
     Reset();
@@ -1308,6 +1352,22 @@ void NocashPrint(u32 ncpu, u32 addr)
 
 
 
+void MonitorARM9Jump(u32 addr)
+{
+    // checkme: can the entrypoint addr be THUMB?
+
+    if ((!RunningGame) && NDSCart::CartROM)
+    {
+        if (addr == *(u32*)&NDSCart::CartROM[0x24])
+        {
+            printf("Game is now booting\n");
+            RunningGame = true;
+        }
+    }
+}
+
+
+
 void HandleTimerOverflow(u32 tid)
 {
     Timer* timer = &Timers[tid];
@@ -1725,16 +1785,20 @@ u8 ARM9Read8(u32 addr)
 
     case 0x08000000:
     case 0x09000000:
-        if (ExMemCnt[0] & (1<<7)) return 0xFF; // TODO: proper open bus
-        //return *(u8*)&NDSCart::CartROM[addr & (NDSCart::CartROMSize-1)];
-        //printf("GBA read8 %08X\n", addr);
-        // TODO!!!
-        return 0xFF;
+        if (ExMemCnt[0] & (1<<7)) return 0x00; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return *(u8*)&GBACart::CartROM[addr & (GBACart::CartROMSize-1)];
+        }
+        return 0xFF; // TODO: proper open bus
 
     case 0x0A000000:
-        if (ExMemCnt[0] & (1<<7)) return 0xFF; // TODO: proper open bus
-        // TODO!!!
-        return 0xFF;
+        if (ExMemCnt[0] & (1<<7)) return 0x00; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return GBACart_SRAM::Read8(addr & (GBACart_SRAM::SRAMLength-1));
+        }
+        return 0xFF; // TODO: proper open bus
     }
 
     printf("unknown arm9 read8 %08X\n", addr);
@@ -1786,16 +1850,20 @@ u16 ARM9Read16(u32 addr)
 
     case 0x08000000:
     case 0x09000000:
-        if (ExMemCnt[0] & (1<<7)) return 0xFFFF; // TODO: proper open bus
-        //return *(u8*)&NDSCart::CartROM[addr & (NDSCart::CartROMSize-1)];
-        //printf("GBA read8 %08X\n", addr);
-        // TODO!!!
-        return 0xFFFF;
+        if (ExMemCnt[0] & (1<<7)) return 0x0000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return *(u16*)&GBACart::CartROM[addr & (GBACart::CartROMSize-1)];
+        }
+        return 0xFFFF; // TODO: proper open bus
 
     case 0x0A000000:
-        if (ExMemCnt[0] & (1<<7)) return 0xFFFF; // TODO: proper open bus
-        // TODO!!!
-        return 0xFFFF;
+        if (ExMemCnt[0] & (1<<7)) return 0x0000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return GBACart_SRAM::Read16(addr & (GBACart_SRAM::SRAMLength-1));
+        }
+        return 0xFFFF; // TODO: proper open bus
     }
 
     //printf("unknown arm9 read16 %08X %08X\n", addr, ARM9->R[15]);
@@ -1847,16 +1915,20 @@ u32 ARM9Read32(u32 addr)
 
     case 0x08000000:
     case 0x09000000:
-        if (ExMemCnt[0] & (1<<7)) return 0xFFFFFFFF; // TODO: proper open bus
-        //return *(u8*)&NDSCart::CartROM[addr & (NDSCart::CartROMSize-1)];
-        //printf("GBA read8 %08X\n", addr);
-        // TODO!!!
-        return 0xFFFFFFFF;
+        if (ExMemCnt[0] & (1<<7)) return 0x00000000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return *(u32*)&GBACart::CartROM[addr & (GBACart::CartROMSize-1)];
+        }
+        return 0xFFFFFFFF; // TODO: proper open bus
 
     case 0x0A000000:
-        if (ExMemCnt[0] & (1<<7)) return 0xFFFFFFFF; // TODO: proper open bus
-        // TODO!!!
-        return 0xFFFFFFFF;
+        if (ExMemCnt[0] & (1<<7)) return 0x00000000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return GBACart_SRAM::Read32(addr & (GBACart_SRAM::SRAMLength-1));
+        }
+        return 0xFFFFFFFF; // TODO: proper open bus
     }
 
     printf("unknown arm9 read32 %08X | %08X %08X\n", addr, ARM9->R[15], ARM9->R[12]);
@@ -1887,6 +1959,27 @@ void ARM9Write8(u32 addr, u8 val)
     case 0x07000000:
         // checkme
         return;
+
+    case 0x08000000:
+    case 0x09000000:
+        if (ExMemCnt[0] & (1<<7)) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            if ((addr & 0x00FFFFFF) >= 0xC4 && (addr & 0x00FFFFFF) <= 0xC9)
+            {
+                GBACart::WriteGPIO(addr & (GBACart::CartROMSize-1), val);
+                return;
+            }
+        }
+        break;
+
+    case 0x0A000000:
+        if (ExMemCnt[0] & (1<<7)) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            GBACart_SRAM::Write8(addr & (GBACart_SRAM::SRAMLength-1), val);
+        }
+        return;
     }
 
     printf("unknown arm9 write8 %08X %02X\n", addr, val);
@@ -1930,6 +2023,29 @@ void ARM9Write16(u32 addr, u16 val)
         if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return;
         *(u16*)&GPU::OAM[addr & 0x7FF] = val;
         return;
+
+    case 0x08000000:
+    case 0x09000000:
+        if (ExMemCnt[0] & (1<<7)) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            // Note: the lower bound is adjusted such that a write starting
+            // there will hit the first byte of the GPIO region.
+            if ((addr & 0x00FFFFFF) >= 0xC3 && (addr & 0x00FFFFFF) <= 0xC9)
+            {
+                GBACart::WriteGPIO(addr & (GBACart::CartROMSize-1), val);
+                return;
+            }
+        }
+        break;
+
+    case 0x0A000000:
+        if (ExMemCnt[0] & (1<<7)) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            GBACart_SRAM::Write16(addr & (GBACart_SRAM::SRAMLength-1), val);
+        }
+        return;
     }
 
     //printf("unknown arm9 write16 %08X %04X\n", addr, val);
@@ -1973,6 +2089,30 @@ void ARM9Write32(u32 addr, u32 val)
         if (!(PowerControl9 & ((addr & 0x400) ? (1<<9) : (1<<1)))) return;
         *(u32*)&GPU::OAM[addr & 0x7FF] = val;
         return;
+
+    case 0x08000000:
+    case 0x09000000:
+        if (ExMemCnt[0] & (1<<7)) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            // Note: the lower bound is adjusted such that a write starting
+            // there will hit the first byte of the GPIO region.
+            if ((addr & 0x00FFFFFF) >= 0xC1 && (addr & 0x00FFFFFF) <= 0xC9)
+            {
+                GBACart::WriteGPIO(addr & (GBACart::CartROMSize-1), val & 0xFF);
+                GBACart::WriteGPIO((addr + 2) & (GBACart::CartROMSize-1), (val >> 16) & 0xFF);
+                return;
+            }
+        }
+        break;
+
+    case 0x0A000000:
+        if (ExMemCnt[0] & (1<<7)) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            GBACart_SRAM::Write32(addr & (GBACart_SRAM::SRAMLength-1), val);
+        }
+        return;
     }
 
     printf("unknown arm9 write32 %08X %08X | %08X\n", addr, val, ARM9->R[15]);
@@ -2051,16 +2191,20 @@ u8 ARM7Read8(u32 addr)
 
     case 0x08000000:
     case 0x09000000:
-        if (!(ExMemCnt[0] & (1<<7))) return 0xFF; // TODO: proper open bus
-        //return *(u8*)&NDSCart::CartROM[addr & (NDSCart::CartROMSize-1)];
-        //printf("GBA read8 %08X\n", addr);
-        // TODO!!!
-        return 0xFF;
+        if (!(ExMemCnt[0] & (1<<7))) return 0x00; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return *(u8*)&GBACart::CartROM[addr & (GBACart::CartROMSize-1)];
+        }
+        return 0xFF; // TODO: proper open bus
 
     case 0x0A000000:
-        if (!(ExMemCnt[0] & (1<<7))) return 0xFF; // TODO: proper open bus
-        // TODO!!!
-        return 0xFF;
+        if (!(ExMemCnt[0] & (1<<7))) return 0x00; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return GBACart_SRAM::Read8(addr & (GBACart_SRAM::SRAMLength-1));
+        }
+        return 0xFF; // TODO: proper open bus
     }
 
     printf("unknown arm7 read8 %08X %08X %08X/%08X\n", addr, ARM7->R[15], ARM7->R[0], ARM7->R[1]);
@@ -2114,16 +2258,20 @@ u16 ARM7Read16(u32 addr)
 
     case 0x08000000:
     case 0x09000000:
-        if (!(ExMemCnt[0] & (1<<7))) return 0xFFFF; // TODO: proper open bus
-        //return *(u8*)&NDSCart::CartROM[addr & (NDSCart::CartROMSize-1)];
-        //printf("GBA read8 %08X\n", addr);
-        // TODO!!!
-        return 0xFFFF;
+        if (!(ExMemCnt[0] & (1<<7))) return 0x0000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return *(u16*)&GBACart::CartROM[addr & (GBACart::CartROMSize-1)];
+        }
+        return 0xFFFF; // TODO: proper open bus
 
     case 0x0A000000:
-        if (!(ExMemCnt[0] & (1<<7))) return 0xFFFF; // TODO: proper open bus
-        // TODO!!!
-        return 0xFFFF;
+        if (!(ExMemCnt[0] & (1<<7))) return 0x0000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return GBACart_SRAM::Read16(addr & (GBACart_SRAM::SRAMLength-1));
+        }
+        return 0xFFFF; // TODO: proper open bus
     }
 
     printf("unknown arm7 read16 %08X %08X\n", addr, ARM7->R[15]);
@@ -2177,16 +2325,20 @@ u32 ARM7Read32(u32 addr)
 
     case 0x08000000:
     case 0x09000000:
-        if (!(ExMemCnt[0] & (1<<7))) return 0xFFFFFFFF; // TODO: proper open bus
-        //return *(u8*)&NDSCart::CartROM[addr & (NDSCart::CartROMSize-1)];
-        //printf("GBA read8 %08X\n", addr);
-        // TODO!!!
-        return 0xFFFFFFFF;
+        if (!(ExMemCnt[0] & (1<<7))) return 0x00000000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return *(u32*)&GBACart::CartROM[addr & (GBACart::CartROMSize-1)];
+        }
+        return 0xFFFFFFFF; // TODO: proper open bus
 
     case 0x0A000000:
-        if (!(ExMemCnt[0] & (1<<7))) return 0xFFFFFFFF; // TODO: proper open bus
-        // TODO!!!
-        return 0xFFFFFFFF;
+        if (!(ExMemCnt[0] & (1<<7))) return 0x00000000; // deselected CPU is 00h-filled
+        if (GBACart::CartInserted)
+        {
+            return GBACart_SRAM::Read32(addr & (GBACart_SRAM::SRAMLength-1));
+        }
+        return 0xFFFFFFFF; // TODO: proper open bus
     }
 
     printf("unknown arm7 read32 %08X | %08X\n", addr, ARM7->R[15]);
@@ -2226,6 +2378,27 @@ void ARM7Write8(u32 addr, u8 val)
     case 0x06800000:
         GPU::WriteVRAM_ARM7<u8>(addr, val);
         return;
+
+    case 0x08000000:
+    case 0x09000000:
+        if (!(ExMemCnt[0] & (1<<7))) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            if ((addr & 0x00FFFFFF) >= 0xC4 && (addr & 0x00FFFFFF) <= 0xC9)
+            {
+                GBACart::WriteGPIO(addr & (GBACart::CartROMSize-1), val);
+                return;
+            }
+        }
+        break;
+
+    case 0x0A000000:
+        if (!(ExMemCnt[0] & (1<<7))) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            GBACart_SRAM::Write8(addr & (GBACart_SRAM::SRAMLength-1), val);
+        }
+        return;
     }
 
     printf("unknown arm7 write8 %08X %02X @ %08X\n", addr, val, ARM7->R[15]);
@@ -2272,6 +2445,29 @@ void ARM7Write16(u32 addr, u16 val)
     case 0x06800000:
         GPU::WriteVRAM_ARM7<u16>(addr, val);
         return;
+
+    case 0x08000000:
+    case 0x09000000:
+        if (!(ExMemCnt[0] & (1<<7))) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            // Note: the lower bound is adjusted such that a write starting
+            // there will hit the first byte of the GPIO region.
+            if ((addr & 0x00FFFFFF) >= 0xC3 && (addr & 0x00FFFFFF) <= 0xC9)
+            {
+                GBACart::WriteGPIO(addr & (GBACart::CartROMSize-1), val);
+                return;
+            }
+        }
+        break;
+
+    case 0x0A000000:
+        if (!(ExMemCnt[0] & (1<<7))) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            GBACart_SRAM::Write16(addr & (GBACart_SRAM::SRAMLength-1), val);
+        }
+        return;
     }
 
     //printf("unknown arm7 write16 %08X %04X @ %08X\n", addr, val, ARM7->R[15]);
@@ -2319,6 +2515,30 @@ void ARM7Write32(u32 addr, u32 val)
     case 0x06800000:
         GPU::WriteVRAM_ARM7<u32>(addr, val);
         return;
+
+    case 0x08000000:
+    case 0x09000000:
+        if (!(ExMemCnt[0] & (1<<7))) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            // Note: the lower bound is adjusted such that a write starting
+            // there will hit the first byte of the GPIO region.
+            if ((addr & 0x00FFFFFF) >= 0xC1 && (addr & 0x00FFFFFF) <= 0xC9)
+            {
+                GBACart::WriteGPIO(addr & (GBACart::CartROMSize-1), val & 0xFF);
+                GBACart::WriteGPIO((addr + 2) & (GBACart::CartROMSize-1), (val >> 16) & 0xFF);
+                return;
+            }
+        }
+        break;
+
+    case 0x0A000000:
+        if (!(ExMemCnt[0] & (1<<7))) return; // deselected CPU, skip the write
+        if (GBACart::CartInserted)
+        {
+            GBACart_SRAM::Write32(addr & (GBACart_SRAM::SRAMLength-1), val);
+        }
+        return;
     }
 
     //printf("unknown arm7 write32 %08X %08X @ %08X\n", addr, val, ARM7->R[15]);
diff --git a/src/NDS.h b/src/NDS.h
index 1b572ea..73c0cb7 100644
--- a/src/NDS.h
+++ b/src/NDS.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -175,6 +175,7 @@ void SetARM9RegionTimings(u32 addrstart, u32 addrend, int buswidth, int nonseq,
 void SetARM7RegionTimings(u32 addrstart, u32 addrend, int buswidth, int nonseq, int seq);
 
 bool LoadROM(const char* path, const char* sram, bool direct);
+bool LoadGBAROM(const char* path, const char* sram);
 void LoadBIOS();
 void SetupDirectBoot();
 void RelocateSave(const char* path, bool write);
@@ -214,6 +215,8 @@ u32 GetPC(u32 cpu);
 u64 GetSysClockCycles(int num);
 void NocashPrint(u32 cpu, u32 addr);
 
+void MonitorARM9Jump(u32 addr);
+
 bool DMAsInMode(u32 cpu, u32 mode);
 bool DMAsRunning(u32 cpu);
 void CheckDMAs(u32 cpu, u32 mode);
diff --git a/src/NDSCart.cpp b/src/NDSCart.cpp
index b0e9837..6a25bcb 100644
--- a/src/NDSCart.cpp
+++ b/src/NDSCart.cpp
@@ -50,7 +50,6 @@ void Write_Null(u8 val, bool islast);
 void Write_EEPROMTiny(u8 val, bool islast);
 void Write_EEPROM(u8 val, bool islast);
 void Write_Flash(u8 val, bool islast);
-void Write_Discover(u8 val, bool islast);
 
 
 bool Init()
@@ -401,7 +400,7 @@ void Write(u8 val, u32 hold)
     switch (CurCmd)
     {
     case 0x00:
-        // Pokémon carts have an IR transceiver thing, and send this
+        // Pokémon carts have an IR transceiver thing, and send this
         // to bypass it and access SRAM.
         // TODO: design better
         CurCmd = val;
@@ -818,7 +817,7 @@ bool ReadROMParams(u32 gamecode, u32* params)
     // [gamecode] [ROM size] [save type] [reserved]
     // list must be sorted by gamecode
 
-    FILE* f = Platform::OpenLocalFile("romlist.bin", "rb");
+    FILE* f = Platform::OpenDataFile("romlist.bin");
     if (!f) return false;
 
     fseek(f, 0, SEEK_END);
@@ -869,6 +868,35 @@ bool ReadROMParams(u32 gamecode, u32* params)
 }
 
 
+void DecryptSecureArea(u8* out)
+{
+    u32 gamecode = *(u32*)&CartROM[0x0C];
+    u32 arm9base = *(u32*)&CartROM[0x20];
+
+    memcpy(out, &CartROM[arm9base], 0x800);
+
+    Key1_InitKeycode(gamecode, 2, 2);
+    Key1_Decrypt((u32*)&out[0]);
+
+    Key1_InitKeycode(gamecode, 3, 2);
+    for (u32 i = 0; i < 0x800; i += 8)
+        Key1_Decrypt((u32*)&out[i]);
+
+    if (!strncmp((const char*)out, "encryObj", 8))
+    {
+        printf("Secure area decryption OK\n");
+        *(u32*)&out[0] = 0xE7FFDEFF;
+        *(u32*)&out[4] = 0xE7FFDEFF;
+    }
+    else
+    {
+        printf("Secure area decryption failed\n");
+        for (u32 i = 0; i < 0x800; i += 4)
+            *(u32*)&out[i] = 0xE7FFDEFF;
+    }
+}
+
+
 bool LoadROM(const char* path, const char* sram, bool direct)
 {
     // TODO: streaming mode? for really big ROMs or systems with limited RAM
@@ -945,28 +973,8 @@ bool LoadROM(const char* path, const char* sram, bool direct)
 
     printf("Cart ID: %08X\n", CartID);
 
-    if (*(u32*)&CartROM[0x20] < 0x4000)
-    {
-        //ApplyDLDIPatch();
-    }
-
-    if (direct)
-    {
-        // TODO: in the case of an already-encrypted secure area, direct boot
-        // needs it decrypted
-        NDS::SetupDirectBoot();
-        CmdEncMode = 2;
-    }
-
-    CartInserted = true;
-
-    // TODO: support more fancy cart types (homebrew?, flashcarts, etc)
-    if (CartID & 0x08000000)
-        ROMCommandHandler = ROMCommand_RetailNAND;
-    else
-        ROMCommandHandler = ROMCommand_Retail;
-
     u32 arm9base = *(u32*)&CartROM[0x20];
+
     if (arm9base < 0x8000)
     {
         if (arm9base >= 0x4000)
@@ -987,22 +995,30 @@ bool LoadROM(const char* path, const char* sram, bool direct)
             }
         }
         else
+        {
             CartIsHomebrew = true;
+            //ApplyDLDIPatch();
+        }
     }
 
-    // re-encrypt modcrypt areas if needed
-    // TODO: somehow detect whether those are already encrypted
-    if (true)
+    if (direct)
     {
-        u32 mod1 = *(u32*)&CartROM[0x220];
-        u32 mod2 = *(u32*)&CartROM[0x228];
+        // TODO: in the case of an already-encrypted secure area, direct boot
+        // needs it decrypted
+        NDS::SetupDirectBoot();
+        CmdEncMode = 2;
+    }
 
-        printf("Re-encrypting modcrypt areas: %08X, %08X\n", mod1, mod2);
+    CartInserted = true;
 
-        if (mod1) ApplyModcrypt(mod1, *(u32*)&CartROM[0x224], &CartROM[0x300]);
-        if (mod2) ApplyModcrypt(mod2, *(u32*)&CartROM[0x22C], &CartROM[0x314]);
-    }
+    // TODO: support more fancy cart types (homebrew?, flashcarts, etc)
+    if (CartID & 0x08000000)
+        ROMCommandHandler = ROMCommand_RetailNAND;
+    else
+        ROMCommandHandler = ROMCommand_Retail;
 
+    // encryption
+    Key1_InitKeycode(gamecode, 2, 2);
 
     // save
     printf("Save file: %s\n", sram);
diff --git a/src/NDSCart.h b/src/NDSCart.h
index 05516d7..adc821f 100644
--- a/src/NDSCart.h
+++ b/src/NDSCart.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -44,6 +44,7 @@ void Reset();
 
 void DoSavestate(Savestate* file);
 
+void DecryptSecureArea(u8* out);
 bool LoadROM(const char* path, const char* sram, bool direct);
 void RelocateSave(const char* path, bool write);
 
diff --git a/src/OpenGLSupport.cpp b/src/OpenGLSupport.cpp
index 59424b4..f91af9b 100644
--- a/src/OpenGLSupport.cpp
+++ b/src/OpenGLSupport.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/OpenGLSupport.h b/src/OpenGLSupport.h
index a08bcdf..5f92580 100644
--- a/src/OpenGLSupport.h
+++ b/src/OpenGLSupport.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/Platform.h b/src/Platform.h
index ca6971e..b6effdc 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -32,15 +32,21 @@ void StopEmu();
 //     can be optionally restricted to only opening a file that already exists.
 // * OpenLocalFile():
 //     opens files local to the emulator (melonDS.ini, BIOS, firmware, ...)
-//     checks, by order of priority:
+//     For Windows builds, or portable UNIX builds it checks, by order of priority:
 //     * current working directory
 //     * emulator directory (essentially where the melonDS executable is) if supported
 //     * any platform-specific application data directories
 //     in create mode, if the file doesn't exist, it will be created in the emulator
 //     directory if supported, or in the current directory otherwise
+//     For regular UNIX builds, the user's configuration directory is always used.
+// * OpenDataFile():
+//     Opens a file that was installed alongside melonDS on UNIX systems in /usr/share, etc.
+//     Looks in the user's data directory first, then the system's.
+//     If on Windows or a portable UNIX build, this simply calls OpenLocalFile().
 
 FILE* OpenFile(const char* path, const char* mode, bool mustexist=false);
 FILE* OpenLocalFile(const char* path, const char* mode);
+FILE* OpenDataFile(const char* path);
 
 inline bool FileExists(const char* name)
 {
diff --git a/src/RTC.cpp b/src/RTC.cpp
index 83e5bdb..0d80b2c 100644
--- a/src/RTC.cpp
+++ b/src/RTC.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/RTC.h b/src/RTC.h
index 7f904a6..05cd80f 100644
--- a/src/RTC.h
+++ b/src/RTC.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/SPI.cpp b/src/SPI.cpp
index 81b0c04..ca334cb 100644
--- a/src/SPI.cpp
+++ b/src/SPI.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/SPI.h b/src/SPI.h
index 73fd57e..21734c4 100644
--- a/src/SPI.h
+++ b/src/SPI.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/SPU.cpp b/src/SPU.cpp
index 8e295c3..158221f 100644
--- a/src/SPU.cpp
+++ b/src/SPU.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/SPU.h b/src/SPU.h
index 53a8e0a..74a4471 100644
--- a/src/SPU.h
+++ b/src/SPU.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/Savestate.cpp b/src/Savestate.cpp
index fff2ec7..0337ff2 100644
--- a/src/Savestate.cpp
+++ b/src/Savestate.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -28,11 +28,7 @@
     04 - version major
     06 - version minor
     08 - length
-    0C - game serial
-    10 - ARM9 binary checksum
-    14 - ARM7 binary checksum
-    18 - reserved
-    1C - reserved
+    0C - reserved (should be game serial later!)
 
     section header:
     00 - section magic
diff --git a/src/Savestate.h b/src/Savestate.h
index ef86f3c..a5447b3 100644
--- a/src/Savestate.h
+++ b/src/Savestate.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -22,8 +22,8 @@
 #include <stdio.h>
 #include "types.h"
 
-#define SAVESTATE_MAJOR 4
-#define SAVESTATE_MINOR 1
+#define SAVESTATE_MAJOR 6
+#define SAVESTATE_MINOR 0
 
 class Savestate
 {
diff --git a/src/Wifi.cpp b/src/Wifi.cpp
index dbe836f..ab82724 100644
--- a/src/Wifi.cpp
+++ b/src/Wifi.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/Wifi.h b/src/Wifi.h
index c97264b..dd3eeb3 100644
--- a/src/Wifi.h
+++ b/src/Wifi.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/WifiAP.cpp b/src/WifiAP.cpp
index 4d4ee19..3a5de37 100644
--- a/src/WifiAP.cpp
+++ b/src/WifiAP.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/WifiAP.h b/src/WifiAP.h
index e62c0fb..97946a5 100644
--- a/src/WifiAP.h
+++ b/src/WifiAP.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/CMakeLists.txt b/src/libui_sdl/CMakeLists.txt
index 64206bf..a3a7f8a 100644
--- a/src/libui_sdl/CMakeLists.txt
+++ b/src/libui_sdl/CMakeLists.txt
@@ -22,23 +22,24 @@ option(BUILD_SHARED_LIBS "Whether to build libui as a shared library or a static
 set(BUILD_SHARED_LIBS OFF)
 add_subdirectory(libui)
 
-find_package(SDL2 REQUIRED)
-include_directories(${SDL2_INCLUDE_DIR})
-#string(STRIP ${SDL2_LIBRARIES} SDL2_LIBRARIES)
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(SDL2 REQUIRED sdl2)
 
 add_executable(melonDS ${SOURCES_LIBUI})
-target_link_libraries(melonDS
-	core ${SDL2_LIBRARIES} libui)
+target_include_directories(melonDS PRIVATE ${SDL2_INCLUDE_DIRS})
+target_link_libraries(melonDS core libui ${SDL2_LIBRARIES})
 
 if (UNIX)
+	option(UNIX_PORTABLE "Make a portable build that looks for its configuration in the current directory" OFF)
+	if (UNIX_PORTABLE)
+		add_definitions(-DUNIX_PORTABLE)
+	endif()
+
 	find_package(PkgConfig REQUIRED)
 	pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
-	pkg_check_modules(SDL2 REQUIRED sdl2)
 
-	target_include_directories(melonDS
-		PRIVATE ${GTK3_INCLUDE_DIRS} ${SDL2_INCLUDE_DIRS}
-	)
-	target_link_libraries(melonDS ${GTK3_LIBRARIES} ${SDL2_LIBRARIES})
+	target_include_directories(melonDS PRIVATE ${GTK3_INCLUDE_DIRS})
+	target_link_libraries(melonDS ${GTK3_LIBRARIES})
 
 	ADD_DEFINITIONS(${GTK3_CFLAGS_OTHER})
 
@@ -58,7 +59,15 @@ if (UNIX)
 elseif (WIN32)
 	target_sources(melonDS PUBLIC "${CMAKE_SOURCE_DIR}/melon.rc")
 	target_include_directories(melonDS PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/..")
-	target_link_libraries(melonDS comctl32 d2d1 dwrite uxtheme ws2_32 iphlpapi)
+	target_link_libraries(melonDS comctl32 d2d1 dwrite uxtheme ws2_32 iphlpapi gdi32)
 endif ()
 
+install(FILES ../../net.kuribo64.melonDS.desktop DESTINATION ${CMAKE_INSTALL_PREFIX}/share/applications)
+install(FILES ../../icon/melon_16x16.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons/hicolor/16x16/apps RENAME net.kuribo64.melonDS.png)
+install(FILES ../../icon/melon_32x32.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons/hicolor/32x32/apps RENAME net.kuribo64.melonDS.png)
+install(FILES ../../icon/melon_48x48.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons/hicolor/48x48/apps RENAME net.kuribo64.melonDS.png)
+install(FILES ../../icon/melon_64x64.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons/hicolor/64x64/apps RENAME net.kuribo64.melonDS.png)
+install(FILES ../../icon/melon_128x128.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons/hicolor/128x128/apps RENAME net.kuribo64.melonDS.png)
+install(FILES ../../icon/melon_256x256.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons/hicolor/256x256/apps RENAME net.kuribo64.melonDS.png)
+install(FILES ../../romlist.bin DESTINATION ${CMAKE_INSTALL_PREFIX}/share/melonDS)
 install(TARGETS melonDS RUNTIME DESTINATION ${CMAKE_INSTALL_PREFIX}/bin)
diff --git a/src/libui_sdl/DlgAudioSettings.cpp b/src/libui_sdl/DlgAudioSettings.cpp
index d649321..43836ae 100644
--- a/src/libui_sdl/DlgAudioSettings.cpp
+++ b/src/libui_sdl/DlgAudioSettings.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgAudioSettings.h b/src/libui_sdl/DlgAudioSettings.h
index f058c25..7a5afcc 100644
--- a/src/libui_sdl/DlgAudioSettings.h
+++ b/src/libui_sdl/DlgAudioSettings.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgEmuSettings.cpp b/src/libui_sdl/DlgEmuSettings.cpp
index 768560d..c50f216 100644
--- a/src/libui_sdl/DlgEmuSettings.cpp
+++ b/src/libui_sdl/DlgEmuSettings.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgEmuSettings.h b/src/libui_sdl/DlgEmuSettings.h
index baff7ce..d937448 100644
--- a/src/libui_sdl/DlgEmuSettings.h
+++ b/src/libui_sdl/DlgEmuSettings.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgInputConfig.cpp b/src/libui_sdl/DlgInputConfig.cpp
index a80e2ec..f4245b4 100644
--- a/src/libui_sdl/DlgInputConfig.cpp
+++ b/src/libui_sdl/DlgInputConfig.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -71,7 +71,9 @@ char hotkeylabels[HK_MAX][32] =
     "Pause/resume:",
     "Reset:",
     "Fast forward:",
-    "Fast forward (toggle):"
+    "Fast forward (toggle):",
+    "Decrease sunlight (Boktai):",
+    "Increase sunlight (Boktai):"
 };
 
 int openedmask;
@@ -514,7 +516,7 @@ void Open(int type)
         memcpy(dlg->keymap, Config::HKKeyMapping, sizeof(int)*HK_MAX);
         memcpy(dlg->joymap, Config::HKJoyMapping, sizeof(int)*HK_MAX);
 
-        dlg->win = uiNewWindow("Hotkey config - melonDS", 600, 100, 0, 0, 0);
+        dlg->win = uiNewWindow("Hotkey config - melonDS", 700, 100, 0, 0, 0);
     }
 
     uiControl(dlg->win)->UserData = dlg;
diff --git a/src/libui_sdl/DlgInputConfig.h b/src/libui_sdl/DlgInputConfig.h
index 94c7325..89ac034 100644
--- a/src/libui_sdl/DlgInputConfig.h
+++ b/src/libui_sdl/DlgInputConfig.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgVideoSettings.cpp b/src/libui_sdl/DlgVideoSettings.cpp
index ff88ba8..1062be1 100644
--- a/src/libui_sdl/DlgVideoSettings.cpp
+++ b/src/libui_sdl/DlgVideoSettings.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgVideoSettings.h b/src/libui_sdl/DlgVideoSettings.h
index 25a938f..17072e0 100644
--- a/src/libui_sdl/DlgVideoSettings.h
+++ b/src/libui_sdl/DlgVideoSettings.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgWifiSettings.cpp b/src/libui_sdl/DlgWifiSettings.cpp
index 09080a0..d1ce8bd 100644
--- a/src/libui_sdl/DlgWifiSettings.cpp
+++ b/src/libui_sdl/DlgWifiSettings.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/DlgWifiSettings.h b/src/libui_sdl/DlgWifiSettings.h
index 466ce10..a12cbfd 100644
--- a/src/libui_sdl/DlgWifiSettings.h
+++ b/src/libui_sdl/DlgWifiSettings.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/LAN_PCap.cpp b/src/libui_sdl/LAN_PCap.cpp
index c228f5e..ce278bc 100644
--- a/src/libui_sdl/LAN_PCap.cpp
+++ b/src/libui_sdl/LAN_PCap.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -133,7 +133,7 @@ bool Init(bool open_adapter)
             return false;
         }
     }
-    
+
     PCapAdapter = NULL;
     PacketLen = 0;
     RXNum = 0;
@@ -172,7 +172,7 @@ bool Init(bool open_adapter)
 #else
         strncpy(adata->DeviceName, dev->name, 127);
         adata->DeviceName[127] = '\0';
-        
+
         strncpy(adata->FriendlyName, adata->DeviceName, 127);
         adata->FriendlyName[127] = '\0';
 #endif // __WIN32__
@@ -250,7 +250,7 @@ bool Init(bool open_adapter)
         printf("getifaddrs() shat itself :(\n");
         return false;
     }
-    
+
     for (int i = 0; i < NumAdapters; i++)
     {
         adata = &Adapters[i];
@@ -262,8 +262,14 @@ bool Init(bool open_adapter)
                 curaddr = curaddr->ifa_next;
                 continue;
             }
-            if (!curaddr->ifa_addr) continue;
-            
+
+            if (!curaddr->ifa_addr)
+            {
+                printf("Device (%s) does not have an address :/\n", curaddr->ifa_name);
+                curaddr = curaddr->ifa_next;
+                continue;
+            }
+
             u16 af = curaddr->ifa_addr->sa_family;
             if (af == AF_INET)
             {
@@ -273,23 +279,23 @@ bool Init(bool open_adapter)
             else if (af == AF_PACKET)
             {
                 struct sockaddr_ll* sa = (sockaddr_ll*)curaddr->ifa_addr;
-                if (sa->sll_halen != 6) 
+                if (sa->sll_halen != 6)
                     printf("weird MAC length %d for %s\n", sa->sll_halen, curaddr->ifa_name);
                 else
                     memcpy(adata->MAC, sa->sll_addr, 6);
             }
-            
+
             curaddr = curaddr->ifa_next;
         }
     }
-    
+
     freeifaddrs(addrs);
 
 #endif // __WIN32__
 
     if (!open_adapter) return true;
     if (PCapAdapter) pcap_close(PCapAdapter);
-    
+
     // open pcap device
     PCapAdapterData = &Adapters[0];
     for (int i = 0; i < NumAdapters; i++)
diff --git a/src/libui_sdl/LAN_PCap.h b/src/libui_sdl/LAN_PCap.h
index 6ca43e8..250b8e9 100644
--- a/src/libui_sdl/LAN_PCap.h
+++ b/src/libui_sdl/LAN_PCap.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/LAN_Socket.cpp b/src/libui_sdl/LAN_Socket.cpp
index a9f2cd7..c6fbd4b 100644
--- a/src/libui_sdl/LAN_Socket.cpp
+++ b/src/libui_sdl/LAN_Socket.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/LAN_Socket.h b/src/libui_sdl/LAN_Socket.h
index a0abe45..8453a5f 100644
--- a/src/libui_sdl/LAN_Socket.h
+++ b/src/libui_sdl/LAN_Socket.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/MelonCap.cpp b/src/libui_sdl/MelonCap.cpp
index fde440a..2658b66 100644
--- a/src/libui_sdl/MelonCap.cpp
+++ b/src/libui_sdl/MelonCap.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -336,8 +336,8 @@ void Update()
             colA &= mask;
             colB &= mask;
 
-            if (colA == colB) WinBitmapData[(y*768) + x + 512] = 0xFF00FF00;
-            else              WinBitmapData[(y*768) + x + 512] = 0xFFFF0000;
+            if (colA == colB) WinBitmapData[(y*768) + x + 512] = 0xFF000000;//0xFF00FF00;
+            else              WinBitmapData[(y*768) + x + 512] = 0xFFFFFFFF;//0xFFFF0000;
         }
     }
 
diff --git a/src/libui_sdl/MelonCap.h b/src/libui_sdl/MelonCap.h
index 1185dea..33a391b 100644
--- a/src/libui_sdl/MelonCap.h
+++ b/src/libui_sdl/MelonCap.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/OSD.cpp b/src/libui_sdl/OSD.cpp
index bd44e99..a01e39b 100644
--- a/src/libui_sdl/OSD.cpp
+++ b/src/libui_sdl/OSD.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/OSD.h b/src/libui_sdl/OSD.h
index afe403f..12294ea 100644
--- a/src/libui_sdl/OSD.h
+++ b/src/libui_sdl/OSD.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/Platform.cpp b/src/libui_sdl/Platform.cpp
index 94b3791..54fa568 100644
--- a/src/libui_sdl/Platform.cpp
+++ b/src/libui_sdl/Platform.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -135,6 +135,66 @@ FILE* OpenFile(const char* path, const char* mode, bool mustexist)
     return ret;
 }
 
+#if !defined(UNIX_PORTABLE) && !defined(__WIN32__)
+
+FILE* OpenLocalFile(const char* path, const char* mode)
+{
+    std::string fullpath;
+    if (path[0] == '/')
+    {
+        // If it's an absolute path, just open that.
+        fullpath = std::string(path);
+    }
+    else
+    {
+        // Check user configuration directory
+        std::string confpath = std::string(g_get_user_config_dir()) + "/melonDS/";
+        g_mkdir_with_parents(confpath.c_str(), 0755);
+        fullpath = confpath + path;
+    }
+
+    return OpenFile(fullpath.c_str(), mode, mode[0] != 'w');
+}
+
+FILE* OpenDataFile(const char* path)
+{
+    const char* melondir = "melonDS";
+    const char* const* sys_dirs = g_get_system_data_dirs();
+    const char* user_dir = g_get_user_data_dir();
+
+    // First check the user's data directory
+    char* fullpath = g_build_path("/", user_dir, melondir, path, NULL);
+    if (access(fullpath, R_OK) == 0)
+    {
+        FILE* f = fopen(fullpath, "r");
+        g_free(fullpath);
+        return f;
+    }
+    free(fullpath);
+
+    // Then check the system data directories
+    for (size_t i = 0; sys_dirs[i] != NULL; i++)
+    {
+        const char* dir = sys_dirs[i];
+        char* fullpath = g_build_path("/", dir, melondir, path, NULL);
+
+        if (access(fullpath, R_OK) == 0)
+        {
+            FILE* f = fopen(fullpath, "r");
+            g_free(fullpath);
+            return f;
+        }
+        free(fullpath);
+    }
+
+	FILE* f = fopen(path, "rb");
+	if (f) return f;
+
+    return NULL;
+}
+
+#else
+
 FILE* OpenLocalFile(const char* path, const char* mode)
 {
     bool relpath = false;
@@ -178,7 +238,7 @@ FILE* OpenLocalFile(const char* path, const char* mode)
         emudirpath[pathlen] = '\0';
     }
 
-    // Locations are application directory, and AppData/melonDS on Windows or XDG_CONFIG_HOME/melonds on Linux
+    // Locations are application directory, and AppData/melonDS on Windows or XDG_CONFIG_HOME/melonDS on Linux
 
     FILE* f;
 
@@ -240,7 +300,7 @@ FILE* OpenLocalFile(const char* path, const char* mode)
     {
         // Now check XDG_CONFIG_HOME
         // TODO: check for memory leak there
-        std::string fullpath = std::string(g_get_user_config_dir()) + "/melonds/" + path;
+        std::string fullpath = std::string(g_get_user_config_dir()) + "/melonDS/" + path;
         f = OpenFile(fullpath.c_str(), mode, true);
         if (f) { delete[] emudirpath; return f; }
     }
@@ -257,6 +317,13 @@ FILE* OpenLocalFile(const char* path, const char* mode)
     return NULL;
 }
 
+FILE* OpenDataFile(const char* path)
+{
+	return OpenLocalFile(path, "rb");
+}
+
+#endif
+
 
 void* Thread_Create(void (*func)())
 {
diff --git a/src/libui_sdl/PlatformConfig.cpp b/src/libui_sdl/PlatformConfig.cpp
index c8ec19f..f78b195 100644
--- a/src/libui_sdl/PlatformConfig.cpp
+++ b/src/libui_sdl/PlatformConfig.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -93,25 +93,29 @@ ConfigEntry PlatformConfigFile[] =
     {"Joy_X",      0, &JoyMapping[10], -1, NULL, 0},
     {"Joy_Y",      0, &JoyMapping[11], -1, NULL, 0},
 
-    {"HKKey_Lid",               0, &HKKeyMapping[HK_Lid],               0x0D, NULL, 0},
-    {"HKKey_Mic",               0, &HKKeyMapping[HK_Mic],               0x35, NULL, 0},
-    {"HKKey_Pause",             0, &HKKeyMapping[HK_Pause],               -1, NULL, 0},
-    {"HKKey_Reset",             0, &HKKeyMapping[HK_Reset],               -1, NULL, 0},
-    {"HKKey_FastForward",       0, &HKKeyMapping[HK_FastForward],       0x0F, NULL, 0},
-    {"HKKey_FastForwardToggle", 0, &HKKeyMapping[HK_FastForwardToggle],   -1, NULL, 0},
-
-    {"HKJoy_Lid",               0, &HKJoyMapping[HK_Lid],               -1, NULL, 0},
-    {"HKJoy_Mic",               0, &HKJoyMapping[HK_Mic],               -1, NULL, 0},
-    {"HKJoy_Pause",             0, &HKJoyMapping[HK_Pause],             -1, NULL, 0},
-    {"HKJoy_Reset",             0, &HKJoyMapping[HK_Reset],             -1, NULL, 0},
-    {"HKJoy_FastForward",       0, &HKJoyMapping[HK_FastForward],       -1, NULL, 0},
-    {"HKJoy_FastForwardToggle", 0, &HKJoyMapping[HK_FastForwardToggle], -1, NULL, 0},
+    {"HKKey_Lid",                 0, &HKKeyMapping[HK_Lid],                 0x0D, NULL, 0},
+    {"HKKey_Mic",                 0, &HKKeyMapping[HK_Mic],                 0x35, NULL, 0},
+    {"HKKey_Pause",               0, &HKKeyMapping[HK_Pause],                 -1, NULL, 0},
+    {"HKKey_Reset",               0, &HKKeyMapping[HK_Reset],                 -1, NULL, 0},
+    {"HKKey_FastForward",         0, &HKKeyMapping[HK_FastForward],         0x0F, NULL, 0},
+    {"HKKey_FastForwardToggle",   0, &HKKeyMapping[HK_FastForwardToggle],     -1, NULL, 0},
+    {"HKKey_SolarSensorDecrease", 0, &HKKeyMapping[HK_SolarSensorDecrease], 0x4B, NULL, 0},
+    {"HKKey_SolarSensorIncrease", 0, &HKKeyMapping[HK_SolarSensorIncrease], 0x4D, NULL, 0},
+
+    {"HKJoy_Lid",                 0, &HKJoyMapping[HK_Lid],                 -1, NULL, 0},
+    {"HKJoy_Mic",                 0, &HKJoyMapping[HK_Mic],                 -1, NULL, 0},
+    {"HKJoy_Pause",               0, &HKJoyMapping[HK_Pause],               -1, NULL, 0},
+    {"HKJoy_Reset",               0, &HKJoyMapping[HK_Reset],               -1, NULL, 0},
+    {"HKJoy_FastForward",         0, &HKJoyMapping[HK_FastForward],         -1, NULL, 0},
+    {"HKJoy_FastForwardToggle",   0, &HKJoyMapping[HK_FastForwardToggle],   -1, NULL, 0},
+    {"HKJoy_SolarSensorDecrease", 0, &HKJoyMapping[HK_SolarSensorDecrease], -1, NULL, 0},
+    {"HKJoy_SolarSensorIncrease", 0, &HKJoyMapping[HK_SolarSensorIncrease], -1, NULL, 0},
 
     {"JoystickID", 0, &JoystickID, 0, NULL, 0},
 
     {"WindowWidth",  0, &WindowWidth,  256, NULL, 0},
     {"WindowHeight", 0, &WindowHeight, 384, NULL, 0},
-    {"WindowMax", 0, &WindowMaximized, 0, NULL, 0},
+    {"WindowMax",    0, &WindowMaximized, 0, NULL, 0},
 
     {"ScreenRotation", 0, &ScreenRotation, 0, NULL, 0},
     {"ScreenGap",      0, &ScreenGap,      0, NULL, 0},
diff --git a/src/libui_sdl/PlatformConfig.h b/src/libui_sdl/PlatformConfig.h
index 842e72a..9e02862 100644
--- a/src/libui_sdl/PlatformConfig.h
+++ b/src/libui_sdl/PlatformConfig.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -29,6 +29,8 @@ enum
     HK_Reset,
     HK_FastForward,
     HK_FastForwardToggle,
+    HK_SolarSensorDecrease,
+    HK_SolarSensorIncrease,
     HK_MAX
 };
 
diff --git a/src/libui_sdl/font.h b/src/libui_sdl/font.h
index 8647b7a..f2e4f87 100644
--- a/src/libui_sdl/font.h
+++ b/src/libui_sdl/font.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/libui_sdl/main.cpp b/src/libui_sdl/main.cpp
index 13fb52a..53396e7 100644
--- a/src/libui_sdl/main.cpp
+++ b/src/libui_sdl/main.cpp
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
@@ -21,6 +21,10 @@
 #include <stdio.h>
 #include <string.h>
 
+#ifndef __WIN32__
+#include <glib.h>
+#endif
+
 #include <SDL2/SDL.h>
 #include "libui/ui.h"
 
@@ -38,6 +42,7 @@
 #include "DlgWifiSettings.h"
 
 #include "../NDS.h"
+#include "../GBACart.h"
 #include "../GPU.h"
 #include "../SPU.h"
 #include "../Wifi.h"
@@ -105,9 +110,9 @@ int EmuRunning;
 volatile int EmuStatus;
 
 bool RunningSomething;
-char ROMPath[1024];
-char SRAMPath[1024];
-char PrevSRAMPath[1024]; // for savestate 'undo load'
+char ROMPath[2][1024];
+char SRAMPath[2][1024];
+char PrevSRAMPath[2][1024]; // for savestate 'undo load'
 
 bool SavestateLoaded;
 
@@ -184,7 +189,7 @@ void SetupScreenRects(int width, int height);
 void TogglePause(void* blarg);
 void Reset(void* blarg);
 
-void SetupSRAMPath();
+void SetupSRAMPath(int slot);
 
 void SaveState(int slot);
 void LoadState(int slot);
@@ -954,6 +959,24 @@ int EmuThreadFunc(void* burp)
         if (HotkeyPressed(HK_Pause)) uiQueueMain(TogglePause, NULL);
         if (HotkeyPressed(HK_Reset)) uiQueueMain(Reset, NULL);
 
+        if (GBACart::CartInserted && GBACart::HasSolarSensor)
+        {
+            if (HotkeyPressed(HK_SolarSensorDecrease))
+            {
+                if (GBACart_SolarSensor::LightLevel > 0) GBACart_SolarSensor::LightLevel--;
+                char msg[64];
+                sprintf(msg, "Solar sensor level set to %d", GBACart_SolarSensor::LightLevel);
+                OSD::AddMessage(0, msg);
+            }
+            if (HotkeyPressed(HK_SolarSensorIncrease))
+            {
+                if (GBACart_SolarSensor::LightLevel < 10) GBACart_SolarSensor::LightLevel++;
+                char msg[64];
+                sprintf(msg, "Solar sensor level set to %d", GBACart_SolarSensor::LightLevel);
+                OSD::AddMessage(0, msg);
+            }
+        }
+
         if (EmuRunning == 1)
         {
             EmuStatus = 1;
@@ -1661,12 +1684,18 @@ void Reset(void* blarg)
     SavestateLoaded = false;
     uiMenuItemDisable(MenuItem_UndoStateLoad);
 
-    if (ROMPath[0] == '\0')
+    if (ROMPath[0][0] == '\0')
         NDS::LoadBIOS();
     else
     {
-        SetupSRAMPath();
-        NDS::LoadROM(ROMPath, SRAMPath, Config::DirectBoot);
+        SetupSRAMPath(0);
+        NDS::LoadROM(ROMPath[0], SRAMPath[0], Config::DirectBoot);
+    }
+
+    if (ROMPath[1][0] != '\0')
+    {
+        SetupSRAMPath(1);
+        NDS::LoadGBAROM(ROMPath[1], SRAMPath[1]);
     }
 
     Run();
@@ -1681,6 +1710,10 @@ void Stop(bool internal)
         while (EmuStatus != 2);
     RunningSomething = false;
 
+    // eject any inserted GBA cartridge
+    GBACart::Eject();
+    ROMPath[1][0] = '\0';
+
     uiWindowSetTitle(MainWindow, "melonDS " MELONDS_VERSION);
 
     for (int i = 0; i < 9; i++) uiMenuItemDisable(MenuItem_SaveStateSlot[i]);
@@ -1701,41 +1734,53 @@ void Stop(bool internal)
     OSD::AddMessage(0xFFC040, "Shutdown");
 }
 
-void SetupSRAMPath()
+void SetupSRAMPath(int slot)
 {
-    strncpy(SRAMPath, ROMPath, 1023);
-    SRAMPath[1023] = '\0';
-    strncpy(SRAMPath + strlen(ROMPath) - 3, "sav", 3);
+    strncpy(SRAMPath[slot], ROMPath[slot], 1023);
+    SRAMPath[slot][1023] = '\0';
+    strncpy(SRAMPath[slot] + strlen(ROMPath[slot]) - 3, "sav", 3);
 }
 
-void TryLoadROM(char* file, int prevstatus)
+void TryLoadROM(char* file, int slot, int prevstatus)
 {
     char oldpath[1024];
     char oldsram[1024];
-    strncpy(oldpath, ROMPath, 1024);
-    strncpy(oldsram, SRAMPath, 1024);
+    strncpy(oldpath, ROMPath[slot], 1024);
+    strncpy(oldsram, SRAMPath[slot], 1024);
 
-    strncpy(ROMPath, file, 1023);
-    ROMPath[1023] = '\0';
+    strncpy(ROMPath[slot], file, 1023);
+    ROMPath[slot][1023] = '\0';
 
-    SetupSRAMPath();
+    SetupSRAMPath(0);
+    SetupSRAMPath(1);
 
-    if (NDS::LoadROM(ROMPath, SRAMPath, Config::DirectBoot))
+    if (slot == 0 && NDS::LoadROM(ROMPath[slot], SRAMPath[slot], Config::DirectBoot))
     {
         SavestateLoaded = false;
         uiMenuItemDisable(MenuItem_UndoStateLoad);
 
-        strncpy(PrevSRAMPath, SRAMPath, 1024); // safety
+        // Reload the inserted GBA cartridge (if any)
+        if (ROMPath[1][0] != '\0') NDS::LoadGBAROM(ROMPath[1], SRAMPath[1]);
+
+        strncpy(PrevSRAMPath[slot], SRAMPath[slot], 1024); // safety
         Run();
     }
+    else if (slot == 1 && NDS::LoadGBAROM(ROMPath[slot], SRAMPath[slot]))
+    {
+        SavestateLoaded = false;
+        uiMenuItemDisable(MenuItem_UndoStateLoad);
+
+        strncpy(PrevSRAMPath[slot], SRAMPath[slot], 1024); // safety
+        if (RunningSomething) Run(); // do not start just from a GBA cart
+    }
     else
     {
         uiMsgBoxError(MainWindow,
                       "Failed to load the ROM",
                       "Make sure the file can be accessed and isn't opened in another application.");
 
-        strncpy(ROMPath, oldpath, 1024);
-        strncpy(SRAMPath, oldsram, 1024);
+        strncpy(ROMPath[slot], oldpath, 1024);
+        strncpy(SRAMPath[slot], oldsram, 1024);
         EmuRunning = prevstatus;
     }
 }
@@ -1748,22 +1793,22 @@ void GetSavestateName(int slot, char* filename, int len)
 {
     int pos;
 
-    if (ROMPath[0] == '\0') // running firmware, no ROM
+    if (ROMPath[0][0] == '\0') // running firmware, no ROM
     {
         strcpy(filename, "firmware");
         pos = 8;
     }
     else
     {
-        int l = strlen(ROMPath);
+        int l = strlen(ROMPath[0]);
         pos = l;
-        while (ROMPath[pos] != '.' && pos > 0) pos--;
+        while (ROMPath[0][pos] != '.' && pos > 0) pos--;
         if (pos == 0) pos = l;
 
         // avoid buffer overflow. shoddy
         if (pos > len-5) pos = len-5;
 
-        strncpy(&filename[0], ROMPath, pos);
+        strncpy(&filename[0], ROMPath[0], pos);
     }
     strcpy(&filename[pos], ".ml");
     filename[pos+3] = '0'+slot;
@@ -1807,6 +1852,8 @@ void LoadState(int slot)
         return;
     }
 
+    u32 oldGBACartCRC = GBACart::CartCRC;
+
     // backup
     Savestate* backup = new Savestate("timewarp.mln", true);
     NDS::DoSavestate(backup);
@@ -1831,21 +1878,36 @@ void LoadState(int slot)
 
     if (!failed)
     {
-        if (Config::SavestateRelocSRAM && ROMPath[0]!='\0')
+        if (Config::SavestateRelocSRAM && ROMPath[0][0]!='\0')
         {
-            strncpy(PrevSRAMPath, SRAMPath, 1024);
+            strncpy(PrevSRAMPath[0], SRAMPath[0], 1024);
+
+            strncpy(SRAMPath[0], filename, 1019);
+            int len = strlen(SRAMPath[0]);
+            strcpy(&SRAMPath[0][len], ".sav");
+            SRAMPath[0][len+4] = '\0';
+
+            NDS::RelocateSave(SRAMPath[0], false);
+        }
 
-            strncpy(SRAMPath, filename, 1019);
-            int len = strlen(SRAMPath);
-            strcpy(&SRAMPath[len], ".sav");
-            SRAMPath[len+4] = '\0';
+        bool loadedPartialGBAROM = false;
 
-            NDS::RelocateSave(SRAMPath, false);
+        // in case we have a GBA cart inserted, and the GBA ROM changes
+        // due to having loaded a save state, we do not want to reload
+        // the previous cartridge on reset, or commit writes to any
+        // loaded save file. therefore, their paths are "nulled".
+        if (GBACart::CartInserted && GBACart::CartCRC != oldGBACartCRC)
+        {
+            ROMPath[1][0] = '\0';
+            SRAMPath[1][0] = '\0';
+            loadedPartialGBAROM = true;
         }
 
         char msg[64];
-        if (slot > 0) sprintf(msg, "State loaded from slot %d", slot);
-        else          sprintf(msg, "State loaded from file");
+        if (slot > 0) sprintf(msg, "State loaded from slot %d%s",
+                        slot, loadedPartialGBAROM ? " (GBA ROM header only)" : "");
+        else          sprintf(msg, "State loaded from file%s",
+                        loadedPartialGBAROM ? " (GBA ROM header only)" : "");
         OSD::AddMessage(0, msg);
 
         SavestateLoaded = true;
@@ -1896,14 +1958,14 @@ void SaveState(int slot)
         if (slot > 0)
             uiMenuItemEnable(MenuItem_LoadStateSlot[slot-1]);
 
-        if (Config::SavestateRelocSRAM && ROMPath[0]!='\0')
+        if (Config::SavestateRelocSRAM && ROMPath[0][0]!='\0')
         {
-            strncpy(SRAMPath, filename, 1019);
-            int len = strlen(SRAMPath);
-            strcpy(&SRAMPath[len], ".sav");
-            SRAMPath[len+4] = '\0';
+            strncpy(SRAMPath[0], filename, 1019);
+            int len = strlen(SRAMPath[0]);
+            strcpy(&SRAMPath[0][len], ".sav");
+            SRAMPath[0][len+4] = '\0';
 
-            NDS::RelocateSave(SRAMPath, true);
+            NDS::RelocateSave(SRAMPath[0], true);
         }
     }
 
@@ -1930,10 +1992,10 @@ void UndoStateLoad()
     NDS::DoSavestate(backup);
     delete backup;
 
-    if (ROMPath[0]!='\0')
+    if (ROMPath[0][0]!='\0')
     {
-        strncpy(SRAMPath, PrevSRAMPath, 1024);
-        NDS::RelocateSave(SRAMPath, false);
+        strncpy(SRAMPath[0], PrevSRAMPath[0], 1024);
+        NDS::RelocateSave(SRAMPath[0], false);
     }
 
     OSD::AddMessage(0, "State load undone");
@@ -1977,7 +2039,11 @@ void OnDropFile(uiWindow* window, char* file, void* blarg)
             while (EmuStatus != 2);
         }
 
-        TryLoadROM(file, prevstatus);
+        TryLoadROM(file, 0, prevstatus);
+    }
+    else if (!strcasecmp(ext, "gba"))
+    {
+        TryLoadROM(file, 1, prevstatus);
     }
 }
 
@@ -2008,7 +2074,7 @@ void OnOpenFile(uiMenuItem* item, uiWindow* window, void* blarg)
     EmuRunning = 2;
     while (EmuStatus != 2);
 
-    char* file = uiOpenFile(window, "DS ROM (*.nds)|*.nds;*.srl|Any file|*.*", Config::LastROMFolder);
+    char* file = uiOpenFile(window, "DS ROM (*.nds)|*.nds;*.srl|GBA ROM (*.gba)|*.gba|Any file|*.*", Config::LastROMFolder);
     if (!file)
     {
         EmuRunning = prevstatus;
@@ -2019,8 +2085,17 @@ void OnOpenFile(uiMenuItem* item, uiWindow* window, void* blarg)
     while (file[pos] != '/' && file[pos] != '\\' && pos > 0) pos--;
     strncpy(Config::LastROMFolder, file, pos);
     Config::LastROMFolder[pos] = '\0';
+    char* ext = &file[strlen(file)-3];
+
+    if (!strcasecmp(ext, "gba"))
+    {
+        TryLoadROM(file, 1, prevstatus);
+    }
+    else
+    {
+        TryLoadROM(file, 0, prevstatus);
+    }
 
-    TryLoadROM(file, prevstatus);
     uiFreeText(file);
 }
 
@@ -2045,8 +2120,14 @@ void OnRun(uiMenuItem* item, uiWindow* window, void* blarg)
 {
     if (!RunningSomething)
     {
-        ROMPath[0] = '\0';
+        ROMPath[0][0] = '\0';
         NDS::LoadBIOS();
+
+        if (ROMPath[1][0] != '\0')
+        {
+            SetupSRAMPath(1);
+            NDS::LoadGBAROM(ROMPath[1], SRAMPath[1]);
+        }
     }
 
     Run();
@@ -2602,6 +2683,7 @@ int main(int argc, char** argv)
     printf("melonDS " MELONDS_VERSION "\n");
     printf(MELONDS_URL "\n");
 
+#if defined(__WIN32__) || defined(UNIX_PORTABLE)
     if (argc > 0 && strlen(argv[0]) > 0)
     {
         int len = strlen(argv[0]);
@@ -2628,6 +2710,13 @@ int main(int argc, char** argv)
         EmuDirectory = new char[2];
         strcpy(EmuDirectory, ".");
     }
+#else
+	const char* confdir = g_get_user_config_dir();
+	const char* confname = "/melonDS";
+	EmuDirectory = new char[strlen(confdir) + strlen(confname) + 1];
+	strcat(EmuDirectory, confdir);
+	strcat(EmuDirectory, confname);
+#endif
 
     // http://stackoverflow.com/questions/14543333/joystick-wont-work-using-sdl
     SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");
@@ -2663,15 +2752,23 @@ int main(int argc, char** argv)
         !Platform::LocalFileExists("bios9.bin") ||
         !Platform::LocalFileExists("firmware.bin"))
     {
-        uiMsgBoxError(
-            NULL,
-            "BIOS/Firmware not found",
+#if defined(__WIN32__) || defined(UNIX_PORTABLE)
+		const char* locationName = "the directory you run melonDS from";
+#else
+		char* locationName = EmuDirectory;
+#endif
+		char msgboxtext[512];
+		sprintf(msgboxtext,
             "One or more of the following required files don't exist or couldn't be accessed:\n\n"
             "bios7.bin -- ARM7 BIOS\n"
             "bios9.bin -- ARM9 BIOS\n"
             "firmware.bin -- firmware image\n\n"
-            "Dump the files from your DS and place them in the directory you run melonDS from.\n"
-            "Make sure that the files can be accessed.");
+            "Dump the files from your DS and place them in %s.\n"
+            "Make sure that the files can be accessed.",
+			locationName
+		);
+
+        uiMsgBoxError(NULL, "BIOS/Firmware not found", msgboxtext);
 
         uiUninit();
         SDL_Quit();
@@ -2717,7 +2814,18 @@ int main(int argc, char** argv)
         }
     }
     {
-        FILE* f = Platform::OpenLocalFile("romlist.bin", "rb");
+        const char* romlist_missing = "Save memory type detection will not work correctly.\n\n"
+            "You should use the latest version of romlist.bin (provided in melonDS release packages).";
+#if !defined(UNIX_PORTABLE) && !defined(__WIN32__)
+        std::string missingstr = std::string(romlist_missing) +
+            "\n\nThe ROM list should be placed in " + g_get_user_data_dir() + "/melonds/, otherwise "
+            "melonDS will search for it in the current working directory.";
+        const char* romlist_missing_text = missingstr.c_str();
+#else
+        const char* romlist_missing_text = romlist_missing;
+#endif
+
+        FILE* f = Platform::OpenDataFile("romlist.bin");
         if (f)
         {
             u32 data;
@@ -2726,18 +2834,12 @@ int main(int argc, char** argv)
 
             if ((data >> 24) == 0) // old CRC-based list
             {
-                uiMsgBoxError(NULL,
-                              "Your version of romlist.bin is outdated.",
-                              "Save memory type detection will not work correctly.\n\n"
-                              "You should use the latest version of romlist.bin (provided in melonDS release packages).");
+                uiMsgBoxError(NULL, "Your version of romlist.bin is outdated.", romlist_missing_text);
             }
         }
         else
         {
-        	uiMsgBoxError(NULL,
-        			     "romlist.bin not found.",
-        			     "Save memory type detection will not work correctly.\n\n"
-				         "You should use the latest version of romlist.bin (provided in melonDS release packages).");
+        	uiMsgBoxError(NULL, "romlist.bin not found.", romlist_missing_text);
         }
     }
 
@@ -2865,14 +2967,30 @@ int main(int argc, char** argv)
 
         if (!strcasecmp(ext, "nds") || !strcasecmp(ext, "srl"))
         {
-            strncpy(ROMPath, file, 1023);
-            ROMPath[1023] = '\0';
+            strncpy(ROMPath[0], file, 1023);
+            ROMPath[0][1023] = '\0';
 
-            SetupSRAMPath();
+            SetupSRAMPath(0);
 
-            if (NDS::LoadROM(ROMPath, SRAMPath, Config::DirectBoot))
+            if (NDS::LoadROM(ROMPath[0], SRAMPath[0], Config::DirectBoot))
                 Run();
         }
+
+        if (argc > 2)
+        {
+            file = argv[2];
+            ext = &file[strlen(file)-3];
+
+            if (!strcasecmp(ext, "gba"))
+            {
+                strncpy(ROMPath[1], file, 1023);
+                ROMPath[1][1023] = '\0';
+
+                SetupSRAMPath(1);
+
+                NDS::LoadGBAROM(ROMPath[1], SRAMPath[1]);
+            }
+        }
     }
 
     uiMain();
diff --git a/src/libui_sdl/main_shaders.h b/src/libui_sdl/main_shaders.h
index 6504520..22d4dd9 100644
--- a/src/libui_sdl/main_shaders.h
+++ b/src/libui_sdl/main_shaders.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/types.h b/src/types.h
index 9b1edc9..234d4c0 100644
--- a/src/types.h
+++ b/src/types.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.
 
diff --git a/src/version.h b/src/version.h
index 0b91540..0045d2a 100644
--- a/src/version.h
+++ b/src/version.h
@@ -1,5 +1,5 @@
 /*
-    Copyright 2016-2019 Arisotura
+    Copyright 2016-2020 Arisotura
 
     This file is part of melonDS.