diff options
Diffstat (limited to 'ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S')
| -rw-r--r-- | ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S b/ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S new file mode 100644 index 0000000000..0ec81734f8 --- /dev/null +++ b/ports/sysdeps/unix/sysv/linux/arm/libc-do-syscall.S @@ -0,0 +1,48 @@ +/* Copyright (C) 2010-2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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> + +/* Out-of-line syscall stub. We expect the system call number in ip + and return the raw result in r0. No registers are clobbered. + We could avoid using the stack for this, but the goal is accurate + unwind information - and while there is a reserved prefix in the + ARM unwind tables for register to register moves, the actual opcodes + are not defined. */ + +#if defined(__thumb__) + .thumb + .syntax unified + .hidden __libc_do_syscall + +#undef CALL_MCOUNT +#define CALL_MCOUNT + +ENTRY (__libc_do_syscall) + .fnstart + push {r7, lr} + .save {r7, lr} + cfi_adjust_cfa_offset (8) + cfi_rel_offset (r7, 0) + cfi_rel_offset (lr, 4) + mov r7, ip + swi 0x0 + pop {r7, pc} + .fnend +END (__libc_do_syscall) + +#endif /* __thumb__ */ |