add device/uefi and device/amd64

src/device/amd64/cpu.go

@@ -0,0 +1,74 @@
+//go:build amd64
+
+package amd64
+
+const (
+	CPUIDTimeStampCounter   = 0x15
+	CPUIDProcessorFrequency = 0x16
+)
+
+type CPUExtendedFamily uint16
+
+const (
+	CPUFamilyIntelCore CPUExtendedFamily = 6
+)
+
+//export asmPause
+func AsmPause()
+
+//export asmReadRdtsc
+func AsmReadRdtsc() uint64
+
+//export asmCpuid
+func AsmCpuid(index uint32, registerEax *uint32, registerEbx *uint32, registerEcx *uint32) int
+
+var maxCpuidIndex uint32
+var stdVendorName0 uint32
+var stdCpuid1Eax uint32
+
+func init() {
+	AsmCpuid(0, &maxCpuidIndex, &stdVendorName0, nil)
+	AsmCpuid(1, &stdCpuid1Eax, nil, nil)
+}
+
+func getExtendedCPUFamily() CPUExtendedFamily {
+	family := CPUExtendedFamily((stdCpuid1Eax >> 8) & 0x0f)
+	family += CPUExtendedFamily((stdCpuid1Eax >> 20) & 0xff)
+	return family
+}
+
+func isIntel() bool {
+	return stdVendorName0 == 0x756e6547
+}
+
+func isIntelFamilyCore() bool {
+	return isIntel() && getExtendedCPUFamily() == CPUFamilyIntelCore
+}
+
+func InternalGetPerformanceCounterFrequency() uint64 {
+	if maxCpuidIndex >= CPUIDTimeStampCounter {
+		return cpuidCoreClockCalculateTSCFrequency()
+	}
+	return 0
+}
+
+func cpuidCoreClockCalculateTSCFrequency() uint64 {
+	var eax uint32
+	var ebx uint32
+	var ecx uint32
+
+	AsmCpuid(CPUIDTimeStampCounter, &eax, &ebx, &ecx)
+	if eax == 0 || ebx == 0 {
+		return 0
+	}
+
+	coreCrystalFrequency := uint64(ecx)
+	if coreCrystalFrequency == 0 {
+		if !isIntelFamilyCore() {
+			return 0
+		}
+		coreCrystalFrequency = 24000000
+	}
+
+	return ((coreCrystalFrequency * uint64(ebx)) + (uint64(eax) / 2)) / uint64(eax)
+}