blob: 3edd381302d7df9567b28d3c60d0dcff436507ae [file] [log] [blame]
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package runtime
import "internal/cpu"
const (
_HWCAP_VFP = 1 << 6
_HWCAP_VFPv3 = 1 << 13
)
func checkgoarm() {
if goarm > 5 && cpu.HWCap&_HWCAP_VFP == 0 {
print("runtime: this CPU has no floating point hardware, so it cannot run\n")
print("this GOARM=", goarm, " binary. Recompile using GOARM=5.\n")
exit(1)
}
if goarm > 6 && cpu.HWCap&_HWCAP_VFPv3 == 0 {
print("runtime: this CPU has no VFPv3 floating point hardware, so it cannot run\n")
print("this GOARM=", goarm, " binary. Recompile using GOARM=5 or GOARM=6.\n")
exit(1)
}
// osinit not called yet, so ncpu not set: must use getncpu directly.
if getncpu() > 1 && goarm < 7 {
print("runtime: this system has multiple CPUs and must use\n")
print("atomic synchronization instructions. Recompile using GOARM=7.\n")
exit(1)
}
}
func archauxv(tag, val uintptr) {
switch tag {
case _AT_HWCAP:
cpu.HWCap = uint(val)
case _AT_HWCAP2:
cpu.HWCap2 = uint(val)
}
}
//go:nosplit
func cputicks() int64 {
// Currently cputicks() is used in blocking profiler and to seed runtime·fastrand().
// runtime·nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
// TODO: need more entropy to better seed fastrand.
return nanotime()
}