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Diffstat (limited to 'src/arch/x86_64.md')
| -rw-r--r-- | src/arch/x86_64.md | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/arch/x86_64.md b/src/arch/x86_64.md index 56e4f63..0ca18cc 100644 --- a/src/arch/x86_64.md +++ b/src/arch/x86_64.md @@ -166,6 +166,17 @@ implemented TSC ticks with a constant frequency. grep constant_tsc /proc/cpuinfo ``` +## Cpu & hw features - `cpuid` +```x86asm +cpuid // in: eax leaf; ecx sub-leaf + // out: eax, ebx, ecx, edx (interpreting depends on leaf) +``` + +This instruction is used to query for availability of certain +instructions or hardware details like cache sizes and son on. + +An example how to read cpuid leafs is show in [cpuid.c](x86/cpuid/cpuid.c). + ## [SysV x86_64 ABI][sysvabi] ### Passing arguments to functions |