github.com/aloncn/graphics-go@v0.0.1/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  func lwp_mcontext_init(mc *mcontextt, stk unsafe.Pointer, mp *m, gp *g, fn uintptr) {
    10  	// Machine dependent mcontext initialisation for LWP.
    11  	mc.__gregs[_REG_R15] = uint32(funcPC(lwp_tramp))
    12  	mc.__gregs[_REG_R13] = uint32(uintptr(stk))
    13  	mc.__gregs[_REG_R0] = uint32(uintptr(unsafe.Pointer(mp)))
    14  	mc.__gregs[_REG_R1] = uint32(uintptr(unsafe.Pointer(gp)))
    15  	mc.__gregs[_REG_R2] = uint32(fn)
    16  }
    17  
    18  func checkgoarm() {
    19  	// TODO(minux): FP checks like in os_linux_arm.go.
    20  
    21  	// osinit not called yet, so ncpu not set: must use getncpu directly.
    22  	if getncpu() > 1 && goarm < 7 {
    23  		print("runtime: this system has multiple CPUs and must use\n")
    24  		print("atomic synchronization instructions. Recompile using GOARM=7.\n")
    25  		exit(1)
    26  	}
    27  }
    28  
    29  //go:nosplit
    30  func cputicks() int64 {
    31  	// Currently cputicks() is used in blocking profiler and to seed runtime·fastrand1().
    32  	// runtime·nanotime() is a poor approximation of CPU ticks that is enough for the profiler.
    33  	// TODO: need more entropy to better seed fastrand1.
    34  	return nanotime()
    35  }