| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * kexec trampoline |
| * |
| * Based on code taken from kexec-tools and kexec-lite. |
| * |
| * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation |
| * Copyright (C) 2006, Mohan Kumar M, IBM Corporation |
| * Copyright (C) 2013, Anton Blanchard, IBM Corporation |
| */ |
| |
| #include <asm/asm-compat.h> |
| |
| .machine ppc64 |
| .balign 256 |
| .globl purgatory_start |
| purgatory_start: |
| b master |
| |
| /* ABI: possible run_at_load flag at 0x5c */ |
| .org purgatory_start + 0x5c |
| .globl run_at_load |
| run_at_load: |
| .long 0 |
| .size run_at_load, . - run_at_load |
| |
| /* ABI: slaves start at 60 with r3=phys */ |
| .org purgatory_start + 0x60 |
| slave: |
| b . |
| /* ABI: end of copied region */ |
| .org purgatory_start + 0x100 |
| .size purgatory_start, . - purgatory_start |
| |
| /* |
| * The above 0x100 bytes at purgatory_start are replaced with the |
| * code from the kernel (or next stage) by setup_purgatory(). |
| */ |
| |
| master: |
| or %r1,%r1,%r1 /* low priority to let other threads catchup */ |
| isync |
| mr %r17,%r3 /* save cpu id to r17 */ |
| mr %r15,%r4 /* save physical address in reg15 */ |
| |
| or %r3,%r3,%r3 /* ok now to high priority, lets boot */ |
| lis %r6,0x1 |
| mtctr %r6 /* delay a bit for slaves to catch up */ |
| bdnz . /* before we overwrite 0-100 again */ |
| |
| bl 0f /* Work out where we're running */ |
| 0: mflr %r18 |
| |
| /* load device-tree address */ |
| ld %r3, (dt_offset - 0b)(%r18) |
| mr %r16,%r3 /* save dt address in reg16 */ |
| li %r4,20 |
| LWZX_BE %r6,%r3,%r4 /* fetch __be32 version number at byte 20 */ |
| cmpwi %cr0,%r6,2 /* v2 or later? */ |
| blt 1f |
| li %r4,28 |
| STWX_BE %r17,%r3,%r4 /* Store my cpu as __be32 at byte 28 */ |
| 1: |
| /* load the kernel address */ |
| ld %r4,(kernel - 0b)(%r18) |
| |
| /* load the run_at_load flag */ |
| /* possibly patched by kexec */ |
| ld %r6,(run_at_load - 0b)(%r18) |
| /* and patch it into the kernel */ |
| stw %r6,(0x5c)(%r4) |
| |
| mr %r3,%r16 /* restore dt address */ |
| |
| li %r5,0 /* r5 will be 0 for kernel */ |
| |
| mfmsr %r11 |
| andi. %r10,%r11,1 /* test MSR_LE */ |
| bne .Little_endian |
| |
| mtctr %r4 /* prepare branch to */ |
| bctr /* start kernel */ |
| |
| .Little_endian: |
| mtsrr0 %r4 /* prepare branch to */ |
| |
| clrrdi %r11,%r11,1 /* clear MSR_LE */ |
| mtsrr1 %r11 |
| |
| rfid /* update MSR and start kernel */ |
| |
| |
| .balign 8 |
| .globl kernel |
| kernel: |
| .8byte 0x0 |
| .size kernel, . - kernel |
| |
| .balign 8 |
| .globl dt_offset |
| dt_offset: |
| .8byte 0x0 |
| .size dt_offset, . - dt_offset |
| |
| |
| .data |
| .balign 8 |
| .globl purgatory_sha256_digest |
| purgatory_sha256_digest: |
| .skip 32 |
| .size purgatory_sha256_digest, . - purgatory_sha256_digest |
| |
| .balign 8 |
| .globl purgatory_sha_regions |
| purgatory_sha_regions: |
| .skip 8 * 2 * 16 |
| .size purgatory_sha_regions, . - purgatory_sha_regions |
