diff options
author | Carmelo Amoroso <carmelo.amoroso@st.com> | 2007-11-16 14:26:46 +0000 |
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committer | Carmelo Amoroso <carmelo.amoroso@st.com> | 2007-11-16 14:26:46 +0000 |
commit | e130b681c43ee2215512ffcf6cadcbc4487e96e6 (patch) | |
tree | 107831cfb61595a907dff264d1bdbf02e18c53f5 /libc/sysdeps/linux/avr32/vfork.S | |
parent | c08b07bc9bff10988100653d280e8afe428249f7 (diff) |
Added AVR32 support to uClibc. Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Diffstat (limited to 'libc/sysdeps/linux/avr32/vfork.S')
-rw-r--r-- | libc/sysdeps/linux/avr32/vfork.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/avr32/vfork.S b/libc/sysdeps/linux/avr32/vfork.S new file mode 100644 index 000000000..d25fbecdb --- /dev/null +++ b/libc/sysdeps/linux/avr32/vfork.S @@ -0,0 +1,58 @@ +/* + * Copyright (C) 2005 Atmel Corporation + * + * This file is subject to the terms and conditions of the GNU Lesser General + * Public License. See the file "COPYING.LIB" in the main directory of this + * archive for more details. + */ + +/* + * Clone the process without copying the address space. The + * calling process is suspended until the child either exits + * or calls execve. + * + * This all means that we cannot rely on the stack to store + * away registers, since they will be overwritten by the child + * as soon as it makes another function call (e.g. execve()). + * Fortunately, the Linux kernel preserves LR across system calls. + */ + +#include <features.h> +#include <sys/syscall.h> + + .global __vfork + .type __vfork,@function + .align 1 +__vfork: + mov r8, __NR_vfork + scall + cp.w r12, -4096 + retls r12 + + /* vfork failed, so we may use the stack freely */ + pushm r4-r7,lr +#ifdef __PIC__ + lddpc r6, .L_GOT + rsub r4, r12, 0 +.L_RGOT: + rsub r6, pc + mcall r6[__errno_location@got] +#else + rsub r4, r12, 0 + mcall .L__errno_location +#endif + st.w r12[0], r4 + popm r4-r7,pc,r12=-1 + + .align 2 +#ifdef __PIC__ +.L_GOT: + .long .L_RGOT - _GLOBAL_OFFSET_TABLE_ +#else +.L__errno_location: + .long __errno_location +#endif + .size __vfork, . - __vfork + +weak_alias(__vfork,vfork) +libc_hidden_weak(vfork) |