kern
view src/segm-asm.S @ 80:4db99a52863e
fixed the "endianess" of the text messages in the ATA identify info block. this
is the first time I've seen wrong byteorder in ascii text, the ATA committee
should be commended.
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Tue, 06 Dec 2011 13:35:39 +0200 |
| parents | 4eaecb14fe31 |
| children |
line source
1 .data
2 .align 4
3 /* memory reserved for setup_selectors */
4 off:.long 0
5 seg:.short 0
6 /* memory reserved for set_gdt */
7 lim:.short 0
8 addr:.long 0
10 .text
11 /* setup_selectors(uint16_t code, uint16_t data)
12 * loads the requested selectors to all the selector registers */
13 .globl setup_selectors
14 setup_selectors:
15 /* set data selectors directly */
16 movl 8(%esp), %eax
17 movw %ax, %ss
18 movw %ax, %es
19 movw %ax, %ds
20 movw %ax, %gs
21 movw %ax, %fs
22 /* set cs using a long jump */
23 movl 4(%esp), %eax
24 movw %ax, (seg)
25 movl $ldcs, (off)
26 ljmp *off
27 ldcs:
28 ret
30 /* set_gdt(uint32_t addr, uint16_t limit)
31 * loads the GDTR with the new address and limit for the GDT */
32 .globl set_gdt
33 set_gdt:
34 movl 4(%esp), %eax
35 movl %eax, (addr)
36 movw 8(%esp), %ax
37 movw %ax, (lim)
38 lgdt (lim)
39 ret
41 /* set_task_reg(uint16_t tss_selector)
42 * loads the TSS selector in the task register */
43 .globl set_task_reg
44 set_task_reg:
45 mov 4(%esp), %eax
46 ltr 4(%esp)
47 ret