/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * 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.
 */
#include <linux/linkage.h>
#include <asm/purgatory.h>

        .text
        .balign 16
        .code64

SYM_CODE_START(purgatory_start)
        /* 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
SYM_CODE_END(purgatory_start)

        .section ".rodata"
        .balign 16
SYM_DATA_START_LOCAL(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
SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)

        .bss
        .balign 4096
SYM_DATA_START_LOCAL(lstack)
        .skip 4096
SYM_DATA_END_LABEL(lstack, SYM_L_LOCAL, lstack_end)