platform_bionic/libc/arch-x86/bionic/syscall.S
Elliott Hughes a85aaf11fa Use the MAX_ERRNO constant.
If you're going to hardcode a constant, you could at least try to
get the constant right...

Change-Id: I886a2593357d1c4dfd6c42649c63e8a35c15a441
2014-01-02 16:23:24 -08:00

51 lines
1.1 KiB
ArmAsm

/*
* Generic syscall call.
* Upon entry:
* %eax: system call number - caller save
* %ebx: arg0 to system call - callee save
* %ecx: arg1 - caller save
* %edx: arg2 - caller save
* %esi: arg3 - callee save
* %edi: arg4 - callee save
* %ebp: arg5 - callee save
*/
#include <private/bionic_asm.h>
ENTRY(syscall)
# Push the callee save registers.
push %ebx
push %esi
push %edi
push %ebp
# Load all the arguments from the calling frame.
# (Not all will be valid, depending on the syscall.)
mov 20(%esp),%eax
mov 24(%esp),%ebx
mov 28(%esp),%ecx
mov 32(%esp),%edx
mov 36(%esp),%esi
mov 40(%esp),%edi
mov 44(%esp),%ebp
# Make the system call.
int $0x80
# Error?
cmpl $-MAX_ERRNO, %eax
jb 1f
# Yes, so set errno.
negl %eax
pushl %eax
call __set_errno
addl $4, %esp
orl $-1, %eax
1:
# Restore the callee save registers.
pop %ebp
pop %edi
pop %esi
pop %ebx
ret
END(syscall)