1 // Copyright 2013 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package runtime 6 7 import "unsafe" 8 9 var hardDiv bool // TODO: set if a hardware divider is available 10 11 func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) { 12 // Machine dependent mcontext initialisation for LWP. 13 mc.__gregs[_REG_R15] = uint32(funcPC(lwp_tramp)) 14 mc.__gregs[_REG_R13] = uint32(uintptr(stk)) 15 mc.__gregs[_REG_R0] = uint32(uintptr(unsafe.Pointer(mp))) 16 mc.__gregs[_REG_R1] = uint32(uintptr(unsafe.Pointer(gp))) 17 mc.__gregs[_REG_R2] = uint32(fn) 18 } 19 20 func checkgoarm() { 21 // TODO(minux): FP checks like in os_linux_arm.go. 22 23 // osinit not called yet, so ncpu not set: must use getncpu directly. 24 if getncpu() > 1 && goarm < 7 { 25 print("runtime: this system has multiple CPUs and must use\n") 26 print("atomic synchronization instructions. Recompile using GOARM=7.\n") 27 exit(1) 28 } 29 } 30 31 //go:nosplit 32 func cputicks() int64 { 33 // Currently cputicks() is used in blocking profiler and to seed runtimefastrand(). 34 // runtimenanotime() is a poor approximation of CPU ticks that is enough for the profiler. 35 // TODO: need more entropy to better seed fastrand. 36 return nanotime() 37 } 38
