forked from Bananymous/banan-os
94 lines
1.2 KiB
ArmAsm
94 lines
1.2 KiB
ArmAsm
// arguments in EAX, EBX, ECX, EDX, ESI, EDI
|
|
.global asm_syscall_handler
|
|
asm_syscall_handler:
|
|
# save segment registers
|
|
pushw %ds
|
|
pushw %es
|
|
pushw %fs
|
|
pushw %gs
|
|
|
|
# save general purpose registers
|
|
pushl %ebx
|
|
pushl %ecx
|
|
pushl %edx
|
|
pushl %edi
|
|
pushl %esi
|
|
pushl %ebp
|
|
cld
|
|
|
|
# align stack
|
|
movl %esp, %ebp
|
|
subl $15, %esp
|
|
andl $0xFFFFFFF0, %esp
|
|
|
|
# push arguments
|
|
subl $4, %esp
|
|
pushl %ebp
|
|
addl $32, (%esp)
|
|
pushl %edi
|
|
pushl %esi
|
|
pushl %edx
|
|
pushl %ecx
|
|
pushl %ebx
|
|
pushl %eax
|
|
|
|
# load kernel segments
|
|
movw $0x10, %ax
|
|
movw %ax, %ds
|
|
movw %ax, %es
|
|
movw %ax, %fs
|
|
movw $0x28, %ax
|
|
movw %ax, %gs
|
|
|
|
call cpp_syscall_handler
|
|
|
|
movl %ebp, %esp
|
|
|
|
# restore general purpose registers
|
|
popl %ebp
|
|
popl %esi
|
|
popl %edi
|
|
popl %edx
|
|
popl %ecx
|
|
popl %ebx
|
|
|
|
# restore segment registers
|
|
popw %gs
|
|
popw %fs
|
|
popw %es
|
|
popw %ds
|
|
|
|
iret
|
|
|
|
.global sys_fork_trampoline
|
|
sys_fork_trampoline:
|
|
pushl %ebp
|
|
pushl %ebx
|
|
pushl %esi
|
|
pushl %edi
|
|
|
|
call read_ip
|
|
testl %eax, %eax
|
|
jz .reload_stack
|
|
|
|
movl %esp, %ebx
|
|
|
|
subl $8, %esp
|
|
pushl %eax
|
|
pushl %ebx
|
|
call sys_fork
|
|
addl $16, %esp
|
|
|
|
.done:
|
|
popl %edi
|
|
popl %esi
|
|
popl %ebx
|
|
popl %ebp
|
|
ret
|
|
|
|
.reload_stack:
|
|
call get_thread_start_sp
|
|
movl %eax, %esp
|
|
xorl %eax, %eax
|
|
jmp .done
|