162306a36Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0-only */ 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * purgatory: setup code 462306a36Sopenharmony_ci * 562306a36Sopenharmony_ci * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com) 662306a36Sopenharmony_ci * Copyright (C) 2014 Red Hat Inc. 762306a36Sopenharmony_ci * 862306a36Sopenharmony_ci * This code has been taken from kexec-tools. 962306a36Sopenharmony_ci */ 1062306a36Sopenharmony_ci#include <linux/linkage.h> 1162306a36Sopenharmony_ci#include <asm/purgatory.h> 1262306a36Sopenharmony_ci 1362306a36Sopenharmony_ci .text 1462306a36Sopenharmony_ci .balign 16 1562306a36Sopenharmony_ci .code64 1662306a36Sopenharmony_ci 1762306a36Sopenharmony_ciSYM_CODE_START(purgatory_start) 1862306a36Sopenharmony_ci /* Load a gdt so I know what the segment registers are */ 1962306a36Sopenharmony_ci lgdt gdt(%rip) 2062306a36Sopenharmony_ci 2162306a36Sopenharmony_ci /* load the data segments */ 2262306a36Sopenharmony_ci movl $0x18, %eax /* data segment */ 2362306a36Sopenharmony_ci movl %eax, %ds 2462306a36Sopenharmony_ci movl %eax, %es 2562306a36Sopenharmony_ci movl %eax, %ss 2662306a36Sopenharmony_ci movl %eax, %fs 2762306a36Sopenharmony_ci movl %eax, %gs 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_ci /* Setup a stack */ 3062306a36Sopenharmony_ci leaq lstack_end(%rip), %rsp 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci /* Call the C code */ 3362306a36Sopenharmony_ci call purgatory 3462306a36Sopenharmony_ci jmp entry64 3562306a36Sopenharmony_ciSYM_CODE_END(purgatory_start) 3662306a36Sopenharmony_ci 3762306a36Sopenharmony_ci .section ".rodata" 3862306a36Sopenharmony_ci .balign 16 3962306a36Sopenharmony_ciSYM_DATA_START_LOCAL(gdt) 4062306a36Sopenharmony_ci /* 0x00 unusable segment 4162306a36Sopenharmony_ci * 0x08 unused 4262306a36Sopenharmony_ci * so use them as the gdt ptr 4362306a36Sopenharmony_ci */ 4462306a36Sopenharmony_ci .word gdt_end - gdt - 1 4562306a36Sopenharmony_ci .quad gdt 4662306a36Sopenharmony_ci .word 0, 0, 0 4762306a36Sopenharmony_ci 4862306a36Sopenharmony_ci /* 0x10 4GB flat code segment */ 4962306a36Sopenharmony_ci .word 0xFFFF, 0x0000, 0x9A00, 0x00AF 5062306a36Sopenharmony_ci 5162306a36Sopenharmony_ci /* 0x18 4GB flat data segment */ 5262306a36Sopenharmony_ci .word 0xFFFF, 0x0000, 0x9200, 0x00CF 5362306a36Sopenharmony_ciSYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) 5462306a36Sopenharmony_ci 5562306a36Sopenharmony_ci .bss 5662306a36Sopenharmony_ci .balign 4096 5762306a36Sopenharmony_ciSYM_DATA_START_LOCAL(lstack) 5862306a36Sopenharmony_ci .skip 4096 5962306a36Sopenharmony_ciSYM_DATA_END_LABEL(lstack, SYM_L_LOCAL, lstack_end) 60