diff options
Diffstat (limited to 'util/x86emu/x86emu/prim_ops.c')
| -rw-r--r-- | util/x86emu/x86emu/prim_ops.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/util/x86emu/x86emu/prim_ops.c b/util/x86emu/x86emu/prim_ops.c index a4a46a2..20e7597 100644 --- a/util/x86emu/x86emu/prim_ops.c +++ b/util/x86emu/x86emu/prim_ops.c @@ -2448,3 +2448,49 @@ DB( if (CHECK_SP_ACCESS()) return res; } +/**************************************************************************** +REMARKS: +CPUID takes EAX/ECX as inputs, writes EAX/EBX/ECX/EDX as output +****************************************************************************/ +void x86emu_cpuid(void) +{ + u32 feature = M.x86.R_EAX; + + switch (feature) { + case 0: + /* Regardless if we have real data from the hardware, the emulator + * will only support upto feature 1, which we set in register EAX. + * Registers EBX:EDX:ECX contain a string identifying the CPU. + */ + M.x86.R_EAX = 1; + /* EBX:EDX:ECX = "GenuineIntel" */ + M.x86.R_EBX = 0x756e6547; + M.x86.R_EDX = 0x49656e69; + M.x86.R_ECX = 0x6c65746e; + break; + case 1: + /* If we don't have x86 compatible hardware, we return values from an + * Intel 486dx4; which was one of the first processors to have CPUID. + */ + M.x86.R_EAX = 0x00000480; + M.x86.R_EBX = 0x00000000; + M.x86.R_ECX = 0x00000000; + M.x86.R_EDX = 0x00000002; /* VME */ + /* In the case that we have hardware CPUID instruction, we make sure + * that the features reported are limited to TSC and VME. + */ + M.x86.R_EDX &= 0x00000012; + break; + default: + /* Finally, we don't support any additional features. Most CPUs + * return all zeros when queried for invalid or unsupported feature + * numbers. + */ + M.x86.R_EAX = 0; + M.x86.R_EBX = 0; + M.x86.R_ECX = 0; + M.x86.R_EDX = 0; + break; + } +} + |
