1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * purgatory:  setup code
4 *
5 * Copyright (C) 2003,2004  Eric Biederman (ebiederm@xmission.com)
6 * Copyright (C) 2014 Red Hat Inc.
7 *
8 * This code has been taken from kexec-tools.
9 */
10#include <linux/linkage.h>
11#include <asm/purgatory.h>
12
13	.text
14	.balign 16
15	.code64
16
17SYM_CODE_START(purgatory_start)
18	/* Load a gdt so I know what the segment registers are */
19	lgdt	gdt(%rip)
20
21	/* load the data segments */
22	movl	$0x18, %eax	/* data segment */
23	movl	%eax, %ds
24	movl	%eax, %es
25	movl	%eax, %ss
26	movl	%eax, %fs
27	movl	%eax, %gs
28
29	/* Setup a stack */
30	leaq	lstack_end(%rip), %rsp
31
32	/* Call the C code */
33	call purgatory
34	jmp	entry64
35SYM_CODE_END(purgatory_start)
36
37	.section ".rodata"
38	.balign 16
39SYM_DATA_START_LOCAL(gdt)
40	/* 0x00 unusable segment
41	 * 0x08 unused
42	 * so use them as the gdt ptr
43	 */
44	.word	gdt_end - gdt - 1
45	.quad	gdt
46	.word	0, 0, 0
47
48	/* 0x10 4GB flat code segment */
49	.word	0xFFFF, 0x0000, 0x9A00, 0x00AF
50
51	/* 0x18 4GB flat data segment */
52	.word	0xFFFF, 0x0000, 0x9200, 0x00CF
53SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
54
55	.bss
56	.balign 4096
57SYM_DATA_START_LOCAL(lstack)
58	.skip 4096
59SYM_DATA_END_LABEL(lstack, SYM_L_LOCAL, lstack_end)
60