sysdeps/unix/sysv/linux/mips/mips64/syscall.S

   1 /* Copyright (C) 2001-2014 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   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
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <sysdep.h>
  19
  20 #include <sys/asm.h>
  21
  22 /* Usage:
  23    long syscall (syscall_number, arg1, arg2, arg3, arg4, arg5, arg6, arg7)
  24
  25    We need to do some arg shifting, syscall_number will be in v0.  */
  26
  27
  28         .text
  29 NESTED (syscall, SZREG, ra)
  30         .mask 0x00010000, -SZREG
  31         .fmask 0x00000000, 0
  32         PTR_ADDIU sp, -SZREG
  33         cfi_adjust_cfa_offset (SZREG)
  34         REG_S s0, (sp)
  35         cfi_rel_offset (s0, 0)
  36
  37         move s0, a0
  38         move a0, a1             /* shift arg1 - arg7.  */
  39         move a1, a2
  40         move a2, a3
  41         move a3, a4
  42         move a4, a5
  43         move a5, a6
  44         move a6, a7
  45
  46         move v0, s0             /* Syscall number -> v0 */
  47         syscall                 /* Do the system call.  */
  48
  49         REG_L s0, (sp)
  50         cfi_restore (s0)
  51         PTR_ADDIU sp, SZREG
  52         cfi_adjust_cfa_offset (-SZREG)
  53         bne a3, zero, L(error)
  54
  55         ret
  56
  57 L(error):
  58         SETUP_GP64_REG (a0, syscall)
  59         PTR_LA t9, __syscall_error
  60         RESTORE_GP64_REG
  61         jr t9
  62
  63 END (syscall)