1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * kexec trampoline 4 * 5 * Based on code taken from kexec-tools and kexec-lite. 6 * 7 * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation 8 * Copyright (C) 2006, Mohan Kumar M, IBM Corporation 9 * Copyright (C) 2013, Anton Blanchard, IBM Corporation 10 */ 11 12#include <asm/asm-compat.h> 13 14 .machine ppc64 15 .balign 256 16 .globl purgatory_start 17purgatory_start: 18 b master 19 20 /* ABI: possible run_at_load flag at 0x5c */ 21 .org purgatory_start + 0x5c 22 .globl run_at_load 23run_at_load: 24 .long 0 25 .size run_at_load, . - run_at_load 26 27 /* ABI: slaves start at 60 with r3=phys */ 28 .org purgatory_start + 0x60 29slave: 30 b . 31 /* ABI: end of copied region */ 32 .org purgatory_start + 0x100 33 .size purgatory_start, . - purgatory_start 34 35/* 36 * The above 0x100 bytes at purgatory_start are replaced with the 37 * code from the kernel (or next stage) by setup_purgatory(). 38 */ 39 40master: 41 or %r1,%r1,%r1 /* low priority to let other threads catchup */ 42 isync 43 mr %r17,%r3 /* save cpu id to r17 */ 44 mr %r15,%r4 /* save physical address in reg15 */ 45 46 or %r3,%r3,%r3 /* ok now to high priority, lets boot */ 47 lis %r6,0x1 48 mtctr %r6 /* delay a bit for slaves to catch up */ 49 bdnz . /* before we overwrite 0-100 again */ 50 51 bl 0f /* Work out where we're running */ 520: mflr %r18 53 54 /* load device-tree address */ 55 ld %r3, (dt_offset - 0b)(%r18) 56 mr %r16,%r3 /* save dt address in reg16 */ 57 li %r4,20 58 LWZX_BE %r6,%r3,%r4 /* fetch __be32 version number at byte 20 */ 59 cmpwi %cr0,%r6,2 /* v2 or later? */ 60 blt 1f 61 li %r4,28 62 STWX_BE %r17,%r3,%r4 /* Store my cpu as __be32 at byte 28 */ 631: 64 /* load the kernel address */ 65 ld %r4,(kernel - 0b)(%r18) 66 67 /* load the run_at_load flag */ 68 /* possibly patched by kexec */ 69 ld %r6,(run_at_load - 0b)(%r18) 70 /* and patch it into the kernel */ 71 stw %r6,(0x5c)(%r4) 72 73 mr %r3,%r16 /* restore dt address */ 74 75 li %r5,0 /* r5 will be 0 for kernel */ 76 77 mfmsr %r11 78 andi. %r10,%r11,1 /* test MSR_LE */ 79 bne .Little_endian 80 81 mtctr %r4 /* prepare branch to */ 82 bctr /* start kernel */ 83 84.Little_endian: 85 mtsrr0 %r4 /* prepare branch to */ 86 87 clrrdi %r11,%r11,1 /* clear MSR_LE */ 88 mtsrr1 %r11 89 90 rfid /* update MSR and start kernel */ 91 92 93 .balign 8 94 .globl kernel 95kernel: 96 .8byte 0x0 97 .size kernel, . - kernel 98 99 .balign 8 100 .globl dt_offset 101dt_offset: 102 .8byte 0x0 103 .size dt_offset, . - dt_offset 104 105 106 .data 107 .balign 8 108.globl purgatory_sha256_digest 109purgatory_sha256_digest: 110 .skip 32 111 .size purgatory_sha256_digest, . - purgatory_sha256_digest 112 113 .balign 8 114.globl purgatory_sha_regions 115purgatory_sha_regions: 116 .skip 8 * 2 * 16 117 .size purgatory_sha_regions, . - purgatory_sha_regions 118