github.com/aloncn/graphics-go@v0.0.1/src/runtime/cgo/gcc_arm.S (about)

     1  // Copyright 2012 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  /*
     6   * Apple still insists on underscore prefixes for C function names.
     7   */
     8  #if defined(__APPLE__)
     9  #define EXT(s) _##s
    10  #else
    11  #define EXT(s) s
    12  #endif
    13  
    14  // Apple's ld64 wants 4-byte alignment for ARM code sections.
    15  // .align in both Apple as and GNU as treat n as aligning to 2**n bytes.
    16  .align	2
    17  
    18  /*
    19   * void crosscall_arm1(void (*fn)(void), void (*setg_gcc)(void *g), void *g)
    20   *
    21   * Calling into the 5c tool chain, where all registers are caller save.
    22   * Called from standard ARM EABI, where r4-r11 are callee-save, so they
    23   * must be saved explicitly.
    24   */
    25  .globl EXT(crosscall_arm1)
    26  EXT(crosscall_arm1):
    27  	push {r4, r5, r6, r7, r8, r9, r10, r11, ip, lr}
    28  	mov r4, r0
    29  	mov r5, r1
    30  	mov r0, r2
    31  
    32  	// Because the assembler might target an earlier revision of the ISA
    33  	// by default, we encode BLX as a .word.
    34  	.word 0xe12fff35 // blx r5 // setg(g)
    35  	.word 0xe12fff34 // blx r4 // fn()
    36  
    37  	pop {r4, r5, r6, r7, r8, r9, r10, r11, ip, pc}
    38  
    39  
    40  #ifdef __ELF__
    41  .section .note.GNU-stack,"",%progbits
    42  #endif