| Vivek Goyal | 8fc5b4d | 2014-08-08 14:26:02 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2003,2004 Eric Biederman (ebiederm@xmission.com) |
| 3 | * Copyright (C) 2014 Red Hat Inc. |
| 4 | |
| 5 | * Author(s): Vivek Goyal <vgoyal@redhat.com> |
| 6 | * |
| 7 | * This code has been taken from kexec-tools. |
| 8 | * |
| 9 | * This source code is licensed under the GNU General Public License, |
| 10 | * Version 2. See the file COPYING for more details. |
| 11 | */ |
| 12 | |
| 13 | .text |
| 14 | .balign 16 |
| 15 | .code64 |
| 16 | .globl entry64, entry64_regs |
| 17 | |
| 18 | |
| 19 | entry64: |
| 20 | /* Setup a gdt that should be preserved */ |
| 21 | lgdt gdt(%rip) |
| 22 | |
| 23 | /* load the data segments */ |
| 24 | movl $0x18, %eax /* data segment */ |
| 25 | movl %eax, %ds |
| 26 | movl %eax, %es |
| 27 | movl %eax, %ss |
| 28 | movl %eax, %fs |
| 29 | movl %eax, %gs |
| 30 | |
| 31 | /* Setup new stack */ |
| 32 | leaq stack_init(%rip), %rsp |
| 33 | pushq $0x10 /* CS */ |
| 34 | leaq new_cs_exit(%rip), %rax |
| 35 | pushq %rax |
| 36 | lretq |
| 37 | new_cs_exit: |
| 38 | |
| 39 | /* Load the registers */ |
| 40 | movq rax(%rip), %rax |
| 41 | movq rbx(%rip), %rbx |
| 42 | movq rcx(%rip), %rcx |
| 43 | movq rdx(%rip), %rdx |
| 44 | movq rsi(%rip), %rsi |
| 45 | movq rdi(%rip), %rdi |
| 46 | movq rsp(%rip), %rsp |
| 47 | movq rbp(%rip), %rbp |
| 48 | movq r8(%rip), %r8 |
| 49 | movq r9(%rip), %r9 |
| 50 | movq r10(%rip), %r10 |
| 51 | movq r11(%rip), %r11 |
| 52 | movq r12(%rip), %r12 |
| 53 | movq r13(%rip), %r13 |
| 54 | movq r14(%rip), %r14 |
| 55 | movq r15(%rip), %r15 |
| 56 | |
| 57 | /* Jump to the new code... */ |
| 58 | jmpq *rip(%rip) |
| 59 | |
| 60 | .section ".rodata" |
| 61 | .balign 4 |
| 62 | entry64_regs: |
| 63 | rax: .quad 0x0 |
| Vivek Goyal | 8fc5b4d | 2014-08-08 14:26:02 -0700 | [diff] [blame] | 64 | rcx: .quad 0x0 |
| 65 | rdx: .quad 0x0 |
| Vivek Goyal | dd5f726 | 2014-08-08 14:26:09 -0700 | [diff] [blame] | 66 | rbx: .quad 0x0 |
| Vivek Goyal | 8fc5b4d | 2014-08-08 14:26:02 -0700 | [diff] [blame] | 67 | rsp: .quad 0x0 |
| 68 | rbp: .quad 0x0 |
| Vivek Goyal | dd5f726 | 2014-08-08 14:26:09 -0700 | [diff] [blame] | 69 | rsi: .quad 0x0 |
| 70 | rdi: .quad 0x0 |
| Vivek Goyal | 8fc5b4d | 2014-08-08 14:26:02 -0700 | [diff] [blame] | 71 | r8: .quad 0x0 |
| 72 | r9: .quad 0x0 |
| 73 | r10: .quad 0x0 |
| 74 | r11: .quad 0x0 |
| 75 | r12: .quad 0x0 |
| 76 | r13: .quad 0x0 |
| 77 | r14: .quad 0x0 |
| 78 | r15: .quad 0x0 |
| 79 | rip: .quad 0x0 |
| 80 | .size entry64_regs, . - entry64_regs |
| 81 | |
| 82 | /* GDT */ |
| 83 | .section ".rodata" |
| 84 | .balign 16 |
| 85 | gdt: |
| 86 | /* 0x00 unusable segment |
| 87 | * 0x08 unused |
| 88 | * so use them as gdt ptr |
| 89 | */ |
| 90 | .word gdt_end - gdt - 1 |
| 91 | .quad gdt |
| 92 | .word 0, 0, 0 |
| 93 | |
| 94 | /* 0x10 4GB flat code segment */ |
| 95 | .word 0xFFFF, 0x0000, 0x9A00, 0x00AF |
| 96 | |
| 97 | /* 0x18 4GB flat data segment */ |
| 98 | .word 0xFFFF, 0x0000, 0x9200, 0x00CF |
| 99 | gdt_end: |
| 100 | stack: .quad 0, 0 |
| 101 | stack_init: |