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Diffstat (limited to 'purgatory/arch/ppc64/v2wrap.S')
| -rw-r--r-- | purgatory/arch/ppc64/v2wrap.S | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/purgatory/arch/ppc64/v2wrap.S b/purgatory/arch/ppc64/v2wrap.S new file mode 100644 index 0000000..3534080 --- /dev/null +++ b/purgatory/arch/ppc64/v2wrap.S @@ -0,0 +1,137 @@ +# +# kexec: Linux boots Linux +# +# Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation +# Copyright (C) 2006, Mohan Kumar M (mohan@in.ibm.com), IBM Corporation +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation (version 2 of the License). +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +# + +#include "ppc64_asm.h" + +# v2wrap.S +# a wrapper to call purgatory code to backup first +# 32kB of first kernel into the backup region +# reserved by kexec-tools. +# Invokes ppc64 kernel with the expected arguments +# of kernel(device-tree, phys-offset, 0) + +# +# calling convention: +# r3 = physical number of this cpu (all cpus) +# r4 = address of this chunk (master only) +# master enters at purgatory_start (aka first byte of this chunk) +# slaves (additional cpus), if any, enter a copy of the +# first 0x100 bytes of this code relocated to 0x0 +# +# in other words, +# a copy of the first 0x100 bytes of this code is copied to 0 +# and the slaves are sent to address 0x60 +# with r3 = their physical cpu number. + +#define LOADADDR(rn,name) \ + lis rn,name##@highest; \ + ori rn,rn,name##@higher; \ + rldicr rn,rn,32,31; \ + oris rn,rn,name##@h; \ + ori rn,rn,name##@l + + .machine ppc64 + .align 8 + .globl purgatory_start +purgatory_start: b master + .org purgatory_start + 0x5c # ABI: possible run_at_load flag at 0x5c + .globl run_at_load +run_at_load: + .long 0 + .size run_at_load, . - run_at_load + .org purgatory_start + 0x60 # ABI: slaves start at 60 with r3=phys +slave: b $ + .org purgatory_start + 0x100 # ABI: end of copied region + .size purgatory_start, . - purgatory_start + +# +# The above 0x100 bytes at purgatory_start are replaced with the +# code from the kernel (or next stage) by kexec/arch/ppc64/kexec-elf-ppc64.c +# + +master: + or 1,1,1 # low priority to let other threads catchup + isync + mr 17,3 # save cpu id to r17 + mr 15,4 # save physical address in reg15 + + LOADADDR(6,my_toc) + ld 2,0(6) #setup toc + + LOADADDR(6,stack) + ld 1,0(6) #setup stack + + subi 1,1,112 + bl DOTSYM(purgatory) + nop + + or 3,3,3 # ok now to high priority, lets boot + lis 6,0x1 + mtctr 6 # delay a bit for slaves to catch up +83: bdnz 83b # before we overwrite 0-100 again + + LOADADDR(16, dt_offset) + ld 3,0(16) # load device-tree address + mr 16,3 # save dt address in reg16 +#ifdef __BIG_ENDIAN__ + lwz 6,20(3) # fetch version number +#else + li 4,20 + lwbrx 6,3,4 # fetch BE version number +#endif + cmpwi 0,6,2 # v2 ? + blt 80f +#ifdef __BIG_ENDIAN__ + stw 17,28(3) # save my cpu number as boot_cpu_phys +#else + li 4,28 + stwbrx 17,3,4 # Store my cpu as BE value +#endif +80: + LOADADDR(6,opal_base) # For OPAL early debug + ld 8,0(6) # load the OPAL base address in r8 + LOADADDR(6,opal_entry) # For OPAL early debug + ld 9,0(6) # load the OPAL entry address in r9 + LOADADDR(6,kernel) + ld 4,0(6) # load the kernel address + LOADADDR(6,run_at_load) # the load flag + lwz 7,0(6) # possibly patched by kexec-elf-ppc64 + stw 7,0x5c(4) # and patch it into the kernel + mr 3,16 # restore dt address + + mfmsr 5 + andi. 10,5,1 # test MSR_LE + bne little_endian + + li 5,0 # r5 will be 0 for kernel + mtctr 4 # prepare branch to + bctr # start kernel + +little_endian: # book3s-only + mtsrr0 4 # prepare branch to + + clrrdi 5,5,1 # clear MSR_LE + mtsrr1 5 + + li 5,0 # r5 will be 0 for kernel + + # skip cache flush, do we care? + + rfid # update MSR and start kernel |