examples/api/crt0.S

   1 /*
   2  * (C) Copyright 2007 Semihalf
   3  *
   4  * Written by: Rafal Jaworowski <raj@semihalf.com>
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #if defined(CONFIG_PPC)
  10
  11         .text
  12         .globl _start
  13 _start:
  14         lis     %r11, search_hint@ha
  15         addi    %r11, %r11, search_hint@l
  16         stw     %r1, 0(%r11)
  17         b       main
  18
  19
  20         .globl syscall
  21 syscall:
  22         lis     %r11, syscall_ptr@ha
  23         addi    %r11, %r11, syscall_ptr@l
  24         lwz     %r11, 0(%r11)
  25         mtctr   %r11
  26         bctr
  27
  28 #elif defined(CONFIG_ARM)
  29
  30         .text
  31         .globl _start
  32 _start:
  33         ldr     ip, =search_hint
  34         str     sp, [ip]
  35         b       main
  36
  37
  38         .globl syscall
  39 syscall:
  40         ldr     ip, =syscall_ptr
  41         ldr     pc, [ip]
  42
  43 #elif defined(CONFIG_MIPS)
  44         .text
  45         .globl __start
  46         .ent __start
  47 __start:
  48         sw      $sp, search_hint
  49         b       main
  50         .end __start
  51
  52         .globl syscall
  53         .ent syscall
  54 syscall:
  55         sw      $ra, return_addr
  56         lw      $t9, syscall_ptr
  57         jalr    $t9
  58         nop
  59         lw      $ra, return_addr
  60         jr      $ra
  61         nop
  62         .end syscall
  63
  64 return_addr:
  65         .align 4
  66         .long 0
  67 #else
  68 #error No support for this arch!
  69 #endif
  70
  71         .globl syscall_ptr
  72 syscall_ptr:
  73         .align  4
  74         .long   0
  75
  76         .globl search_hint
  77 search_hint:
  78         .long   0