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