59 lines
1.1 KiB
ArmAsm
59 lines
1.1 KiB
ArmAsm
|
/*
|
||
|
* purgatory: setup code
|
||
|
*
|
||
|
* Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com)
|
||
|
* Copyright (C) 2014 Red Hat Inc.
|
||
|
*
|
||
|
* This code has been taken from kexec-tools.
|
||
|
*
|
||
|
* This source code is licensed under the GNU General Public License,
|
||
|
* Version 2. See the file COPYING for more details.
|
||
|
*/
|
||
|
|
||
|
.text
|
||
|
.globl purgatory_start
|
||
|
.balign 16
|
||
|
purgatory_start:
|
||
|
.code64
|
||
|
|
||
|
/* Load a gdt so I know what the segment registers are */
|
||
|
lgdt gdt(%rip)
|
||
|
|
||
|
/* load the data segments */
|
||
|
movl $0x18, %eax /* data segment */
|
||
|
movl %eax, %ds
|
||
|
movl %eax, %es
|
||
|
movl %eax, %ss
|
||
|
movl %eax, %fs
|
||
|
movl %eax, %gs
|
||
|
|
||
|
/* Setup a stack */
|
||
|
leaq lstack_end(%rip), %rsp
|
||
|
|
||
|
/* Call the C code */
|
||
|
call purgatory
|
||
|
jmp entry64
|
||
|
|
||
|
.section ".rodata"
|
||
|
.balign 16
|
||
|
gdt: /* 0x00 unusable segment
|
||
|
* 0x08 unused
|
||
|
* so use them as the gdt ptr
|
||
|
*/
|
||
|
.word gdt_end - gdt - 1
|
||
|
.quad gdt
|
||
|
.word 0, 0, 0
|
||
|
|
||
|
/* 0x10 4GB flat code segment */
|
||
|
.word 0xFFFF, 0x0000, 0x9A00, 0x00AF
|
||
|
|
||
|
/* 0x18 4GB flat data segment */
|
||
|
.word 0xFFFF, 0x0000, 0x9200, 0x00CF
|
||
|
gdt_end:
|
||
|
|
||
|
.bss
|
||
|
.balign 4096
|
||
|
lstack:
|
||
|
.skip 4096
|
||
|
lstack_end:
|