github.com/rohankumardubey/syslog-redirector-golang@v0.0.0-20140320174030-4859f03d829a/src/pkg/runtime/sys_arm.c (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  #include "runtime.h"
     6  
     7  // adjust Gobuf as if it executed a call to fn with context ctxt
     8  // and then did an immediate Gosave.
     9  void
    10  runtime·gostartcall(Gobuf *gobuf, void (*fn)(void), void *ctxt)
    11  {
    12  	if(gobuf->lr != 0)
    13  		runtime·throw("invalid use of gostartcall");
    14  	gobuf->lr = gobuf->pc;
    15  	gobuf->pc = (uintptr)fn;
    16  	gobuf->ctxt = ctxt;
    17  }
    18  
    19  // Called to rewind context saved during morestack back to beginning of function.
    20  // To help us, the linker emits a jmp back to the beginning right after the
    21  // call to morestack. We just have to decode and apply that jump.
    22  void
    23  runtime·rewindmorestack(Gobuf *gobuf)
    24  {
    25  	uint32 inst;
    26  
    27  	inst = *(uint32*)gobuf->pc;
    28  	if((gobuf->pc&3) == 0 && (inst>>24) == 0x9a) {
    29  		//runtime·printf("runtime: rewind pc=%p to pc=%p\n", gobuf->pc, gobuf->pc + ((int32)(inst<<8)>>6) + 8);
    30  		gobuf->pc += ((int32)(inst<<8)>>6) + 8;
    31  		return;
    32  	}
    33  	runtime·printf("runtime: pc=%p %x\n", gobuf->pc, inst);
    34  	runtime·throw("runtime: misuse of rewindmorestack");
    35  }