1/* 2 * kexec trampoline 3 * 4 * Based on code taken from kexec-tools and kexec-lite. 5 * 6 * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation 7 * Copyright (C) 2006, Mohan Kumar M, IBM Corporation 8 * Copyright (C) 2013, Anton Blanchard, IBM Corporation 9 * 10 * This program is free software; you can redistribute it and/or modify it under 11 * the terms of the GNU General Public License as published by the Free 12 * Software Foundation (version 2 of the License). 13 */ 14 15#if defined(__LITTLE_ENDIAN__) 16#define STWX_BE stwbrx 17#define LWZX_BE lwbrx 18#elif defined(__BIG_ENDIAN__) 19#define STWX_BE stwx 20#define LWZX_BE lwzx 21#else 22#error no endianness defined! 23#endif 24 25 .machine ppc64 26 .balign 256 27 .globl purgatory_start 28purgatory_start: 29 b master 30 31 /* ABI: possible run_at_load flag at 0x5c */ 32 .org purgatory_start + 0x5c 33 .globl run_at_load 34run_at_load: 35 .long 0 36 .size run_at_load, . - run_at_load 37 38 /* ABI: slaves start at 60 with r3=phys */ 39 .org purgatory_start + 0x60 40slave: 41 b . 42 /* ABI: end of copied region */ 43 .org purgatory_start + 0x100 44 .size purgatory_start, . - purgatory_start 45 46/* 47 * The above 0x100 bytes at purgatory_start are replaced with the 48 * code from the kernel (or next stage) by setup_purgatory(). 49 */ 50 51master: 52 or %r1,%r1,%r1 /* low priority to let other threads catchup */ 53 isync 54 mr %r17,%r3 /* save cpu id to r17 */ 55 mr %r15,%r4 /* save physical address in reg15 */ 56 57 or %r3,%r3,%r3 /* ok now to high priority, lets boot */ 58 lis %r6,0x1 59 mtctr %r6 /* delay a bit for slaves to catch up */ 60 bdnz . /* before we overwrite 0-100 again */ 61 62 bl 0f /* Work out where we're running */ 630: mflr %r18 64 65 /* load device-tree address */ 66 ld %r3, (dt_offset - 0b)(%r18) 67 mr %r16,%r3 /* save dt address in reg16 */ 68 li %r4,20 69 LWZX_BE %r6,%r3,%r4 /* fetch __be32 version number at byte 20 */ 70 cmpwi %cr0,%r6,2 /* v2 or later? */ 71 blt 1f 72 li %r4,28 73 STWX_BE %r17,%r3,%r4 /* Store my cpu as __be32 at byte 28 */ 741: 75 /* load the kernel address */ 76 ld %r4,(kernel - 0b)(%r18) 77 78 /* load the run_at_load flag */ 79 /* possibly patched by kexec */ 80 ld %r6,(run_at_load - 0b)(%r18) 81 /* and patch it into the kernel */ 82 stw %r6,(0x5c)(%r4) 83 84 mr %r3,%r16 /* restore dt address */ 85 86 li %r5,0 /* r5 will be 0 for kernel */ 87 88 mfmsr %r11 89 andi. %r10,%r11,1 /* test MSR_LE */ 90 bne .Little_endian 91 92 mtctr %r4 /* prepare branch to */ 93 bctr /* start kernel */ 94 95.Little_endian: 96 mtsrr0 %r4 /* prepare branch to */ 97 98 clrrdi %r11,%r11,1 /* clear MSR_LE */ 99 mtsrr1 %r11 100 101 rfid /* update MSR and start kernel */ 102 103 104 .balign 8 105 .globl kernel 106kernel: 107 .8byte 0x0 108 .size kernel, . - kernel 109 110 .balign 8 111 .globl dt_offset 112dt_offset: 113 .8byte 0x0 114 .size dt_offset, . - dt_offset 115 116 117 .data 118 .balign 8 119.globl purgatory_sha256_digest 120purgatory_sha256_digest: 121 .skip 32 122 .size purgatory_sha256_digest, . - purgatory_sha256_digest 123 124 .balign 8 125.globl purgatory_sha_regions 126purgatory_sha_regions: 127 .skip 8 * 2 * 16 128 .size purgatory_sha_regions, . - purgatory_sha_regions 129