1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0-only */ 2*4882a593Smuzhiyun/* 3*4882a593Smuzhiyun * purgatory: setup code 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com) 6*4882a593Smuzhiyun * Copyright (C) 2014 Red Hat Inc. 7*4882a593Smuzhiyun * 8*4882a593Smuzhiyun * This code has been taken from kexec-tools. 9*4882a593Smuzhiyun */ 10*4882a593Smuzhiyun#include <linux/linkage.h> 11*4882a593Smuzhiyun#include <asm/purgatory.h> 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun .text 14*4882a593Smuzhiyun .balign 16 15*4882a593Smuzhiyun .code64 16*4882a593Smuzhiyun 17*4882a593SmuzhiyunSYM_CODE_START(purgatory_start) 18*4882a593Smuzhiyun /* Load a gdt so I know what the segment registers are */ 19*4882a593Smuzhiyun lgdt gdt(%rip) 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun /* load the data segments */ 22*4882a593Smuzhiyun movl $0x18, %eax /* data segment */ 23*4882a593Smuzhiyun movl %eax, %ds 24*4882a593Smuzhiyun movl %eax, %es 25*4882a593Smuzhiyun movl %eax, %ss 26*4882a593Smuzhiyun movl %eax, %fs 27*4882a593Smuzhiyun movl %eax, %gs 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun /* Setup a stack */ 30*4882a593Smuzhiyun leaq lstack_end(%rip), %rsp 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun /* Call the C code */ 33*4882a593Smuzhiyun call purgatory 34*4882a593Smuzhiyun jmp entry64 35*4882a593SmuzhiyunSYM_CODE_END(purgatory_start) 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun .section ".rodata" 38*4882a593Smuzhiyun .balign 16 39*4882a593SmuzhiyunSYM_DATA_START_LOCAL(gdt) 40*4882a593Smuzhiyun /* 0x00 unusable segment 41*4882a593Smuzhiyun * 0x08 unused 42*4882a593Smuzhiyun * so use them as the gdt ptr 43*4882a593Smuzhiyun */ 44*4882a593Smuzhiyun .word gdt_end - gdt - 1 45*4882a593Smuzhiyun .quad gdt 46*4882a593Smuzhiyun .word 0, 0, 0 47*4882a593Smuzhiyun 48*4882a593Smuzhiyun /* 0x10 4GB flat code segment */ 49*4882a593Smuzhiyun .word 0xFFFF, 0x0000, 0x9A00, 0x00AF 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun /* 0x18 4GB flat data segment */ 52*4882a593Smuzhiyun .word 0xFFFF, 0x0000, 0x9200, 0x00CF 53*4882a593SmuzhiyunSYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun .bss 56*4882a593Smuzhiyun .balign 4096 57*4882a593SmuzhiyunSYM_DATA_START_LOCAL(lstack) 58*4882a593Smuzhiyun .skip 4096 59*4882a593SmuzhiyunSYM_DATA_END_LABEL(lstack, SYM_L_LOCAL, lstack_end) 60