diff options
Diffstat (limited to 'asm/usermode.s')
| -rw-r--r-- | asm/usermode.s | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/asm/usermode.s b/asm/usermode.s index acf4b04..67eca04 100644 --- a/asm/usermode.s +++ b/asm/usermode.s @@ -1,8 +1,9 @@ -.global asm_usermode -.extern userfunc +.global usermode -# pass address to func to exec (TODO) -asm_usermode: +usermode: + + mov 0x4(%esp),%edx //get adress of passed : void func() + //to be called in ring 3 // 0x23 is user data segment (|2 low bits) // 0x1b is user code segment (|2 low bits) @@ -13,6 +14,7 @@ asm_usermode: mov %ax, %es mov %ax, %fs mov %ax, %gs + // ss is handled by iret mov %esp, %eax @@ -25,10 +27,11 @@ asm_usermode: //mov $0x200, %eax //push %eax // eflags image pushl $0x1B // return code segment selector - push $userfunc // return instruction pointer + push %edx // return instruction pointer + iret - jmp . // will never be reached? + jmp . // never to be reached |