annotate src/proc-asm.S @ 78:251a65b62223
of course I forgot to actually add the new files... every fucking time...
| author |
John Tsiombikas <nuclear@member.fsf.org> |
| date |
Tue, 06 Dec 2011 12:56:46 +0200 |
| parents |
437360696883 |
| children |
|
| rev |
line source |
|
nuclear@54
|
1 .text
|
|
nuclear@57
|
2 /* switch_stack(uint32_t new_stack, uint32_t *old_stack_ptr)
|
|
nuclear@57
|
3 * switches to the new stack and returns the old stack pointer, which is
|
|
nuclear@57
|
4 * also copied to the address passed as the second argument.
|
|
nuclear@54
|
5 */
|
|
nuclear@54
|
6 .globl switch_stack
|
|
nuclear@54
|
7 switch_stack:
|
|
nuclear@57
|
8 movl %esp, %eax /* old stack in eax */
|
|
nuclear@57
|
9 movl 8(%esp), %edx
|
|
nuclear@57
|
10 cmpl $0, %edx /* if old_stack_ptr is null, skip ahead */
|
|
nuclear@57
|
11 jz oldp_is_null
|
|
nuclear@57
|
12 movl %eax, (%edx) /* otherwise *old_stack_ptr = eax */
|
|
nuclear@57
|
13 oldp_is_null:
|
|
nuclear@57
|
14 movl 4(%esp), %esp /* set the new stack */
|
|
nuclear@54
|
15 ret
|
|
nuclear@57
|
16
|
|
nuclear@57
|
17 /* get_instr_stack_ptr(uint32_t *eip, uint32_t *esp)
|
|
nuclear@57
|
18 * returns the current instruction and stack pointers at the same
|
|
nuclear@57
|
19 * point in execution, so that a newly-forked process with these
|
|
nuclear@57
|
20 * values will just return from this function and continue on.
|
|
nuclear@57
|
21 */
|
|
nuclear@57
|
22 .globl get_instr_stack_ptr
|
|
nuclear@57
|
23 get_instr_stack_ptr:
|
|
nuclear@57
|
24 call get_instr_ptr
|
|
nuclear@57
|
25 movl %eax, 4(%esp)
|
|
nuclear@57
|
26 movl %esp, 8(%esp)
|
|
nuclear@57
|
27 ret
|
|
nuclear@57
|
28
|
|
nuclear@57
|
29 /* get_instr_ptr(void)
|
|
nuclear@57
|
30 * returns the address of the next instruction after the call to this function
|
|
nuclear@57
|
31 */
|
|
nuclear@57
|
32 .globl get_instr_ptr
|
|
nuclear@57
|
33 get_instr_ptr:
|
|
nuclear@57
|
34 movl (%esp), %eax
|
|
nuclear@57
|
35 ret
|
|
nuclear@57
|
36
|
|
nuclear@57
|
37 /* get_caller_instr_ptr(void)
|
|
nuclear@57
|
38 * returns the address of the next instruction after the call to the function that
|
|
nuclear@57
|
39 * called this function.
|
|
nuclear@57
|
40 * NOTE: will only work properly when called from a function that uses ebp to point
|
|
nuclear@57
|
41 * to its stack frame, which means all of the C functions but pretty much none of
|
|
nuclear@57
|
42 * our assembly functions.
|
|
nuclear@57
|
43 */
|
|
nuclear@57
|
44 .globl get_caller_instr_ptr
|
|
nuclear@57
|
45 get_caller_instr_ptr:
|
|
nuclear@57
|
46 movl 4(%ebp), %eax
|
|
nuclear@57
|
47 ret
|
|
nuclear@57
|
48
|
|
nuclear@58
|
49 /* this is where we end up when we first context_switch to a newly forked
|
|
nuclear@58
|
50 * process. The interrupt frame is already there, so we just call intr_ret
|
|
nuclear@58
|
51 * to return to user space
|
|
nuclear@58
|
52 */
|
|
nuclear@57
|
53 .globl just_forked
|
|
nuclear@57
|
54 just_forked:
|
|
nuclear@57
|
55 call intr_ret
|
