22 lines
639 B
C
22 lines
639 B
C
|
void enter_user_space()
|
||
|
|
{
|
||
|
|
asm volatile("cli; \
|
||
|
|
mov $0x23, %ax; \
|
||
|
|
mov %ax, %ds; \
|
||
|
|
mov %ax, %es; \
|
||
|
|
mov %ax, %fs; \
|
||
|
|
mov %ax, %gs; \
|
||
|
|
mov %esp, %eax; \
|
||
|
|
push $0x23; \
|
||
|
|
push %eax; \
|
||
|
|
pushf; \
|
||
|
|
pop %eax; \
|
||
|
|
or $0x200, %eax; \
|
||
|
|
push %eax; \
|
||
|
|
push $0x1B; \
|
||
|
|
push $user_code_entry; \
|
||
|
|
iret; \
|
||
|
|
user_code_entry: \
|
||
|
|
call main; \
|
||
|
|
");
|
||
|
|
}
|