Leahnaya/Pokemon-Gen3-to-Gen-X
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Remove alignment assumption

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Lorenzooone 2024-09-08 06:44:07 +02:00
parent 4aca1adaef
commit 652e30f888
1 changed files with 18 additions and 3 deletions
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21
source/decompress.s
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@ -48,10 +48,24 @@ swi_LZ77UnCompWrite8bit:
@ bit0-3: reserved
@ bit4-7: compressed type (1 for LZ77)
@ bit8-31: size of compressed data
ldr r2, [r0], #4
lsrs r2, r2, #8
ldrb r2, [r0, #0]
lsr r2, r2, #4
@ Stop if this isn't LZ77
cmp r2, #1
bne .lz77_16bit_end
@ Don't make any assumption about initial alignment to
@ read the size of the data
ldrb r2, [r0, #1]
ldrb r3, [r0, #2]
lsl r3, r3, #8
orr r2, r2, r3
ldrb r3, [r0, #3]
add r0, r0, #4
lsl r3, r3, #16
orrs r2, r2, r3
@ ignore zero-length decompression requests
beq .lz77_16bit_done
beq .lz77_16bit_end
@ Cover un-aligned destination
tst r1, #1
@ -234,5 +248,6 @@ swi_LZ77UnCompWrite8bit:
orrne r7, r6, lsl #8
strneh r7, [r1, #-1]
.lz77_16bit_end:
ldmfd sp!, {r3 - r8}
bx lr