github.com/stingnevermore/go@v0.0.0-20180120041312-3810f5bfed72/src/runtime/os_netbsd_arm.go (about)

     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 runtime·fastrand().
    34  	// runtime·nanotime() 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  }