| /* Copyright (C) 1996-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by David Mosberger <davidm@azstarnet.com>, 1996. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sysdep.h> |
| |
| /* |
| * This is for COMPATIBILITY with Linux/x86 only. Linux/Alpha system |
| * calls return an error indication in a3. This allows arbitrary 64bit |
| * values to be returned in v0 (because negative values are not |
| * mistaken as error numbers). However, C allows only one value to |
| * be returned, so the interface below folds the error indication passed in |
| * a3 back into v0: it sets v0 to -errno if an error occurs. Thus, |
| * no negative 64bit numbers can be returned. To avoid this problem, |
| * use assembly stubs wherever possible/convenient. |
| * |
| * Usage: |
| * |
| * long syscall(syscall_number, arg1, arg2, arg3, arg4, arg5, arg6) |
| * |
| * syscall_number = the index of the system call we're invoking |
| * arg1-arg6 = up to 6 integer arguments to the system call |
| * |
| * We need to do some arg shifting: the kernel expects the |
| * syscall number in v0 and the first six args in a0-a5. |
| * |
| */ |
| |
| |
| LEAF(__syscall, 0) |
| #ifdef PROF |
| ldgp gp, 0(pv) |
| .set noat |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| .set at |
| .prologue 1 |
| #else |
| .prologue 0 |
| #endif |
| |
| mov a0, v0 /* Syscall number -> v0 */ |
| mov a1, a0 /* arg1-arg5 -> a0-a4 */ |
| mov a2, a1 |
| mov a3, a2 |
| mov a4, a3 |
| mov a5, a4 |
| ldq a5,0(sp) /* arg6 -> a5 */ |
| |
| call_pal PAL_callsys /* Invoke system call */ |
| bne a3, SYSCALL_ERROR_LABEL |
| ret |
| |
| PSEUDO_END(__syscall) |
| |
| weak_alias (__syscall, syscall) |
