diff options
Diffstat (limited to 'purgatory/arch/ppc/v2wrap_32.S')
| -rw-r--r-- | purgatory/arch/ppc/v2wrap_32.S | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/purgatory/arch/ppc/v2wrap_32.S b/purgatory/arch/ppc/v2wrap_32.S new file mode 100644 index 0000000..8b60677 --- /dev/null +++ b/purgatory/arch/ppc/v2wrap_32.S @@ -0,0 +1,95 @@ +# +# 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. +# + +# v2wrap.S +# a wrapper to call purgatory code to backup first +# 32kB of first kernel into the backup region +# reserved by kexec-tools. +# Invokes powerpc 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. + + .globl purgatory_start +purgatory_start: b master + .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/powerpc/kexec-powerpc.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 + + lis 6,my_thread_ptr@h + ori 6,6,my_thread_ptr@l + lwz 2,0(6) # setup ThreadPointer(TP) + + lis 6,stack@h + ori 6,6,stack@l + lwz 1,0(6) #setup stack + + subi 1,1,112 + bl 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 + + lis 6,dt_offset@h + ori 6,6,dt_offset@l + lwz 3,0(6) # load device-tree address + lwz 6,20(3) # fetch version number + cmpwi 0,6,2 # v2 ? + blt 80f + stw 17,28(3) # save my cpu number as boot_cpu_phys +80: + lis 6,kernel@h + ori 6,6,kernel@l + lwz 4,0(6) # load the kernel address + li 5,0 # r5 will be 0 for kernel + li 6,0 # clear r6 for good measure + mtctr 4 # prepare branch too + + lwz 8,0(4) # get the first instruction that we stole + stw 8,0(0) # and put it in the slave loop at 0 + # skip cache flush, do we care? + + bctr # start kernel |