mirror of
https://github.com/henrydcase/nobs.git
synced 2024-11-22 07:15:32 +00:00
34 lines
923 B
Go
34 lines
923 B
Go
// +build amd64,!noasm
|
|
|
|
// Sets capabilities flags for x86 according to information received from
|
|
// CPUID. It was written in accordance with
|
|
// "Intel® 64 and IA-32 Architectures Developer's Manual: Vol. 2A".
|
|
// https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-2a-manual.html
|
|
|
|
package utils
|
|
|
|
// Performs CPUID and returns values of registers
|
|
// go:nosplit
|
|
func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
|
|
|
|
// Returns true in case bit 'n' in 'bits' is set, otherwise false
|
|
func bitn(bits uint32, n uint8) bool {
|
|
return (bits>>n)&1 == 1
|
|
}
|
|
|
|
func init() {
|
|
// CPUID returns max possible input that can be requested
|
|
max, _, _, _ := cpuid(0, 0)
|
|
if max < 7 {
|
|
return
|
|
}
|
|
|
|
_, ecx, _, _ := cpuid(1, 0)
|
|
X86.HasAES = bitn(ecx, 25)
|
|
|
|
_, ecx, _, _ = cpuid(7, 0)
|
|
X86.HasBMI2 = bitn(ecx, 8)
|
|
X86.HasADX = bitn(ecx, 19)
|
|
X86.HasRDSEED = bitn(ecx, 18)
|
|
}
|