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Added GetCrc16 bios function

This commit is contained in:
normmatt234 2006-11-17 06:04:58 +00:00
parent 175d6e88e9
commit 2dd424f630
1 changed files with 21 additions and 2 deletions
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23
desmume/src/bios.c
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@ -929,6 +929,25 @@ u32 getVolumeTab(armcpu_t* cpu)
return 1;
}
u32 getCRC16(armcpu_t* cpu)
{
int i,j;
u32 crc;
u16 start = cpu->R[0];
u16 datap = cpu->R[1];
u32 size = cpu->R[2];
static u16 val[] = { 0xC0C1,0xC181,0xC301,0xC601,0xCC01,0xD801,0xF001,0xA001 };
for(i=datap; i<(datap+size); i++)
{
crc=crc ^ MMU_readHWord(cpu->proc_ID,datap+i);
for(j=0; j<7; j++) crc=crc >> 1; if(crc) crc=crc ^ (val[j] << (7-j));
}
cpu->R[0] = crc;
return 1;
}
u32 (* ARM9_swi_tab[32])(armcpu_t* cpu)={
bios_nop, // 0x00
bios_nop, // 0x01
@ -944,7 +963,7 @@ u32 (* ARM9_swi_tab[32])(armcpu_t* cpu)={
copy, // 0x0B
fastCopy, // 0x0C
bios_sqrt, // 0x0D
bios_nop, // 0x0E
getCRC16, // 0x0E
bios_nop, // 0x0F
BitUnPack, // 0x10
LZ77UnCompWram, // 0x11
@ -979,7 +998,7 @@ u32 (* ARM7_swi_tab[32])(armcpu_t* cpu)={
copy, // 0x0B
fastCopy, // 0x0C
bios_sqrt, // 0x0D
bios_nop, // 0x0E
getCRC16, // 0x0E
bios_nop, // 0x0F
BitUnPack, // 0x10
LZ77UnCompWram, // 0x11