src/system/libroot/os/arch/x86_64/syscalls.inc

   1 /*
   2  * Copyright 2012, Alex Smith, alex@alex-smith.me.uk.
   3  * Distributed under the terms of the MIT License.
   4  */
   5
   6
   7 #include <asm_defs.h>
   8
   9
  10 // The kernel follows the AMD64 ABI for parameter passing (first 6 arguments in
  11 // registers and the remaining ones in on the stack), except that RCX (argument
  12 // 4) is overwritten by the SYSCALL instruction, so it is moved to R10. Syscall
  13 // number goes in RAX.
  14
  15
  16 #define _SYSCALL_NO_RCX(name, n)        \
  17         .align 8;                                               \
  18         FUNCTION(name):                                 \
  19                 movq    $n, %rax;                       \
  20                 syscall;                                        \
  21                 ret;                                            \
  22         FUNCTION_END(name)
  23
  24 #define _SYSCALL_RCX(name, n)           \
  25         .align 8;                                               \
  26         FUNCTION(name):                                 \
  27                 movq    %rcx, %r10;                     \
  28                 movq    $n, %rax;                       \
  29                 syscall;                                        \
  30                 ret;                                            \
  31         FUNCTION_END(name)
  32
  33
  34 #define SYSCALL0(name, n)       _SYSCALL_NO_RCX(name, n)
  35 #define SYSCALL1(name, n)       _SYSCALL_NO_RCX(name, n)
  36 #define SYSCALL2(name, n)       _SYSCALL_NO_RCX(name, n)
  37 #define SYSCALL3(name, n)       _SYSCALL_NO_RCX(name, n)
  38 #define SYSCALL4(name, n)       _SYSCALL_RCX(name, n)
  39 #define SYSCALL5(name, n)       _SYSCALL_RCX(name, n)
  40 #define SYSCALL6(name, n)       _SYSCALL_RCX(name, n)
  41 #define SYSCALL7(name, n)       _SYSCALL_RCX(name, n)
  42 #define SYSCALL8(name, n)       _SYSCALL_RCX(name, n)
  43 #define SYSCALL9(name, n)       _SYSCALL_RCX(name, n)
  44 #define SYSCALL10(name, n)      _SYSCALL_RCX(name, n)
  45 #define SYSCALL11(name, n)      _SYSCALL_RCX(name, n)
  46 #define SYSCALL12(name, n)      _SYSCALL_RCX(name, n)
  47 #define SYSCALL13(name, n)      _SYSCALL_RCX(name, n)
  48 #define SYSCALL14(name, n)      _SYSCALL_RCX(name, n)
  49 #define SYSCALL15(name, n)      _SYSCALL_RCX(name, n)
  50 #define SYSCALL16(name, n)      _SYSCALL_RCX(name, n)
  51 #define SYSCALL17(name, n)      _SYSCALL_RCX(name, n)
  52 #define SYSCALL18(name, n)      _SYSCALL_RCX(name, n)
  53 #define SYSCALL19(name, n)      _SYSCALL_RCX(name, n)
  54 #define SYSCALL20(name, n)      _SYSCALL_RCX(name, n)
  55