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aux/cpuid: hack for amd64

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This commit is contained in:
cinap_lenrek 2014-02-17 19:50:02 +01:00
parent 2c5c784255
commit 152c9d525b
1 changed files with 30 additions and 13 deletions
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43
sys/src/cmd/aux/cpuid.c
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@ -11,17 +11,26 @@ typedef struct Res {
Biobuf *out;
uchar _cpuid[] = {
0x8B, 0x44, 0x24, 0x08, /* MOV 8(SP), AX */
0x31, 0xDB, /* XOR BX, BX */
0x8B, 0x4C, 0x24, 0x0C, /* MOV 12(SP), CX */
0x31, 0xD2, /* XOR DX, DX */
0x0F, 0xA2, /* CPUID */
0x8B, 0x7C, 0x24, 0x04, /* MOV 4(SP), DI */
0x89, 0x07, /* MOV AX, (DI) */
0x89, 0x5F, 0x04, /* MOV BX, 4(DI) */
0x89, 0x4F, 0x08, /* MOV CX, 8(DI) */
0x89, 0x57, 0x0C, /* MOV DX, 12(DI) */
0xC3 /* RET */
0x5E, /* POP SI (PC) */
0x5D, /* POP BP (Res&) */
0x58, /* POP AX */
0x59, /* POP CX */
0x51, /* PUSH CX */
0x50, /* PUSH AX */
0x55, /* PUSH BP */
0x56, /* PUSH SI */
0x31, 0xDB, /* XOR BX, BX */
0x31, 0xD2, /* XOR DX, DX */
0x0F, 0xA2, /* CPUID */
0x89, 0x45, 0x00, /* MOV AX, 0(BP) */
0x89, 0x5d, 0x04, /* MOV BX, 4(BP) */
0x89, 0x4d, 0x08, /* MOV CX, 8(BP) */
0x89, 0x55, 0x0C, /* MOV DX, 12(BP) */
0xC3, /* RET */
};
Res (*cpuid)(ulong ax, ulong cx) = (Res(*)(ulong, ulong)) _cpuid;
@ -215,10 +224,18 @@ main(int argc, char **argv)
case 'a': aflag++; break;
} ARGEND;
notify(notehand);
w = *(ulong *)0x1000;
/* first long in a.out header */
w = *(ulong *)(((uintptr)main)&~0xfff);
notify(nil);
if(w != 0xeb010000)
switch(w){
default:
sysfatal(Egreg);
case 0x978a0000: /* amd64 */
/* patch out POP BP -> POP AX */
_cpuid[1] = 0x58;
case 0xeb010000: /* 386 */
break;
}
Binit(&buf, 1, OWRITE);
out = &buf;
r = cpuid(0, 0);