cprt0.as 4.2 KB

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  1. /* Startup code for ARM & ELF
  2. Copyright (C) 1995, 1996, 1997, 1998, 2001, 2002 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. /* This is the canonical entry point, usually the first thing in the text
  17. segment.
  18. Note that the code in the .init section has already been run.
  19. This includes _init and _libc_init
  20. At this entry point, most registers' values are unspecified, except:
  21. a1 Contains a function pointer to be registered with `atexit'.
  22. This is how the dynamic linker arranges to have DT_FINI
  23. functions called for shared libraries that have been loaded
  24. before this code runs.
  25. sp The stack contains the arguments and environment:
  26. 0(sp) argc
  27. 4(sp) argv[0]
  28. ...
  29. (4*argc)(sp) NULL
  30. (4*(argc+1))(sp) envp[0]
  31. ...
  32. NULL
  33. */
  34. .text
  35. .globl _start
  36. .type _start,#function
  37. _start:
  38. /* Clear the frame pointer since this is the outermost frame. */
  39. mov fp, #0
  40. ldmia sp!, {a2}
  41. /* Pop argc off the stack and save a pointer to argv */
  42. ldr ip,=operatingsystem_parameter_argc
  43. ldr a3,=operatingsystem_parameter_argv
  44. str a2,[ip]
  45. /* calc envp */
  46. add a4,a2,#1
  47. add a4,sp,a4,LSL #2
  48. ldr ip,=operatingsystem_parameter_envp
  49. str sp,[a3]
  50. str a4,[ip]
  51. /* Save initial stackpointer */
  52. ldr ip,=__stkptr
  53. str sp,[ip]
  54. /* Fetch address of fini */
  55. ldr ip, =_fini
  56. /* argc already loaded to a2*/
  57. /* load argv */
  58. mov a3, sp
  59. /* Push stack limit */
  60. str a3, [sp, #-4]!
  61. /* Push rtld_fini */
  62. str a1, [sp, #-4]!
  63. /* Set up the other arguments in registers */
  64. ldr a1, =PASCALMAIN
  65. ldr a4, =_init
  66. /* Push fini */
  67. str ip, [sp, #-4]!
  68. /* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end) */
  69. /* Let the libc call main and exit with its return code. */
  70. bl __libc_start_main
  71. /* should never get here....*/
  72. bl abort
  73. .globl _haltproc
  74. .type _haltproc,#function
  75. _haltproc:
  76. ldr r0,=operatingsystem_result
  77. ldrb r0,[r0]
  78. swi 0x900001
  79. b _haltproc
  80. .globl _haltproc_eabi
  81. .type _haltproc_eabi,#function
  82. _haltproc_eabi:
  83. ldr r0,=operatingsystem_result
  84. ldrb r0,[r0]
  85. mov r7,#248
  86. swi 0x0
  87. b _haltproc_eabi
  88. /* Define a symbol for the first piece of initialized data. */
  89. .data
  90. .globl __data_start
  91. __data_start:
  92. .long 0
  93. .weak data_start
  94. data_start = __data_start
  95. .bss
  96. .comm __stkptr,4
  97. .comm operatingsystem_parameter_envp,4
  98. .comm operatingsystem_parameter_argc,4
  99. .comm operatingsystem_parameter_argv,4
  100. .section ".comment"
  101. .byte 0
  102. .ascii "generated by FPC http://www.freepascal.org\0"
  103. /* We need this stuff to make gdb behave itself, otherwise
  104. gdb will chokes with SIGILL when trying to debug apps.
  105. */
  106. .section ".note.ABI-tag", "a"
  107. .align 4
  108. .long 1f - 0f
  109. .long 3f - 2f
  110. .long 1
  111. 0: .asciz "GNU"
  112. 1: .align 4
  113. 2: .long 0
  114. .long 2,0,0
  115. 3: .align 4
  116. .section .note.GNU-stack,"",%progbits