diff options
Diffstat (limited to 'freebios')
| -rwxr-xr-x | freebios/bios_common.S | 72 | ||||
| -rwxr-xr-x | freebios/drastic_bios_arm7.bin | bin | 16384 -> 16384 bytes | |||
| -rwxr-xr-x | freebios/drastic_bios_arm9.bin | bin | 4096 -> 4096 bytes |
3 files changed, 70 insertions, 2 deletions
diff --git a/freebios/bios_common.S b/freebios/bios_common.S index a2d0d2b..56d349e 100755 --- a/freebios/bios_common.S +++ b/freebios/bios_common.S @@ -627,13 +627,12 @@ swi_bit_unpack: #define lz77_control r3 #define lz77_value r4 +#define lz77_vram_tmp r5 #define lz77_value_b r14 #define window_length r14 #define window_offset r12 #define window_ptr r12 -// TODO: Do a separate version for VRAM -swi_lz77_decompress_vram: swi_lz77_decompress_wram: ldr header, [ source ], #4 movs length, header, lsr #8 @@ -686,6 +685,75 @@ swi_lz77_decompress_wram: movs lz77_control, lz77_control, lsl #1 bpl 1b b 0b + + +swi_lz77_decompress_vram: + ldr header, [ source ], #4 + movs length, header, lsr #8 + beq swi_complete + + stmdb sp!, { r5 } + mov r5, #0 + + 0: + ldrb lz77_control, [ source ], #1 + // This will hit the MSB after 8 iterations + orr lz77_control, lz77_control, #(1 << 23) + + 1: + tst lz77_control, #0x80 + beq 2f + + // Load a window of data that was loaded before + + // Read 16-bit unaligned value + ldrb lz77_value, [ source ], #1 + ldrb lz77_value_b, [ source ], #1 + orr lz77_value, lz77_value_b, lz77_value, lsl #8 + + // Get length and offset from lz77 value + mov window_length, lz77_value, lsr #12 + bic window_offset, lz77_value, #0xF000 + + add window_length, window_length, #3 + sub window_ptr, dest, window_offset + sub window_ptr, window_ptr, #1 + + 3: + tst dest, #1 + ldreqb lz77_vram_tmp, [ window_ptr ], #1 + ldrneb lz77_value, [ window_ptr ], #1 + orrne lz77_value, lz77_vram_tmp, lz77_value, lsl #8 + strneh lz77_value, [ dest, #-1 ] + add dest, dest, #1 + + subs length, length, #1 + ldmeqia sp!, { r5 } + beq swi_complete + + subs window_length, window_length, #1 + bne 3b + + movs lz77_control, lz77_control, lsl #1 + bpl 1b + b 0b + + // Load a single value + 2: + tst dest, #1 + ldreqb lz77_vram_tmp, [ source ], #1 + ldrneb lz77_value, [ source ], #1 + orrne lz77_value, lz77_vram_tmp, lz77_value, lsl #8 + strneh lz77_value, [ dest, #-1 ] + add dest, dest, #1 + + subs length, length, #1 + ldmeqia sp!, { r5 } + beq swi_complete + + movs lz77_control, lz77_control, lsl #1 + bpl 1b + b 0b // TODO: Needs to be implemented diff --git a/freebios/drastic_bios_arm7.bin b/freebios/drastic_bios_arm7.bin Binary files differindex 7f13f60..e586eb9 100755 --- a/freebios/drastic_bios_arm7.bin +++ b/freebios/drastic_bios_arm7.bin diff --git a/freebios/drastic_bios_arm9.bin b/freebios/drastic_bios_arm9.bin Binary files differindex af19b42..51a8282 100755 --- a/freebios/drastic_bios_arm9.bin +++ b/freebios/drastic_bios_arm9.bin |