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/******************************************************************************
* Copyright (c) 2004, 2008 IBM Corporation
* All rights reserved.
* This program and the accompanying materials
* are made available under the terms of the BSD License
* which accompanies this distribution, and is available at
* http://www.opensource.org/licenses/bsd-license.php
*
* Contributors:
* IBM Corporation - initial implementation
*****************************************************************************/
#include <rtas.h>
/*
Function:
Input:
r3: Destination to copy rtas code to
r4: Configuration
Output:
r3: Entry point for rtas calls
Decription: Called by OpenFirmware to instantiate rtas, needs to copy
itself to destination, also do a relocations.
*/
.extern rtas_entry
.extern .stack
.extern _got
.extern _got_end
.extern __bss_start
.extern __bss_end
.extern rtas_config
.section ".rtasstart","ax";
.align 3
.globl _rtas_start
_rtas_start:
mflr r10 # save link register
bcl 20,31,.over # branch (always) to .over
.base:
.align 3
/* Our Open Firmware needs to know the size of the RTAS binary and the
* size & address of the RTAS function jump table. SLOF always looks for this
* information in the following three quads here at the very beginning of the
* RTAS binary at offset 8. So DO NOT DELETE/MOVE them! */
._rtas_size: .quad _rtas_end-_rtas_start
._ptr_to_func_tab: .quad rtas_func_tab-_rtas_start
._ptr_to_func_tab_size: .quad rtas_func_tab_size-_rtas_start
/* The other variables are not accessed by SLOF anymore: */
._rel_offset: .quad _reloc_table_start-_rtas_start
._rel_end_offset: .quad _reloc_table_end-_rtas_start
._bss_offset: .quad __bss_start-_rtas_start
._bss_end_offset: .quad __bss_end-_rtas_start
._rtas_entry_offset: .quad rtas_entry-_rtas_start
._rtas_config_offset: .quad rtas_config-_rtas_start
._rtas_stack: .quad .stack-_rtas_start+RTAS_STACKSIZE-0x60
._rtas_toc: .quad _got-_rtas_start
.over:
mflr r8 # gpr 8 is the base
addi r8,r8,_rtas_start-.base # points to _rtas_start
mr r11,r4 # Save config value
# Copy rtas code
ld r5,._rtas_size-_rtas_start(r8)
mr r4,r8 # Start of rtas
addi r6,r3,-8 # Destination
addi r4,r4,-8 # Source
srdi r5,r5,3 # Count in quads
mtctr r5
0:
ldu r0,8(r4)
stdu r0,8(r6)
bdnz 0b
# Clear bss
ld r4,._bss_offset-_rtas_start(r8)
ld r5,._bss_end_offset-_rtas_start(r8)
li r0,0
add r6,r3,r4 # Address bss in copied code
addi r6,r6,-8
sub r5,r5,r4 # Calculate bss size
srdi r5,r5,3 # Count in quads
mtctr r5
0:
stdu r0,8(r6)
bdnz 0b
# Relocate got
ld r4, ._rel_offset-_rtas_start(r8)
ld r5, ._rel_end_offset-_rtas_start(r8)
sub r5, r5,r4 # Calculate reloc table size
cmpdi r5, 0 # No reloc table ?
beq 1f
add r4, r4, r3 # Calculate reloc table address
addi r4, r4, -4
srdi r5, r5, 2 # Count in words
mtctr r5
0:
lwzu r6, 4(r4) # Load offset out of reloc table
ldx r0, r6, r3 # Load value
add r0, r0, r3 # Add relocation offset = load address
stdx r0, r6, r3
bdnz 0b
1:
# Save config data
ld r5,._rtas_config_offset-_rtas_start(r8)
add r5,r5,r3
std r11,0(r5)
# Flush to memory
mr r4,r3 # Destination address
ld r5,._rtas_size-_rtas_start(r8)
add r5,r5,r4
addi r5,r5,127
rlwinm r4,r4,0,0,24
rlwinm r5,r5,0,0,24
sub r5,r5,r4
srwi r5,r5,7
mtctr r5
0:
dcbst 0,r4
sync
icbi 0,r4
sync
isync
addi r4,r4,128
bdnz 0b
# Call init function
mfmsr r11 # Switch to 64 bit mode
mr r7,r11
rotldi r11,r11,1
ori r11,r11,1
rotldi r11,r11,63
mtmsrd r11
isync
mr r9,r1 # save old stack pointer
ld r1,._rtas_stack-_rtas_start(r8) # load new stack pointer
add r1,r1,r3
std r9,0(r1) # save stack pointer
std r2,64(r1) # save toc
std r7,72(r1) # save old msr value
ld r2,._rtas_toc-_rtas_start(r8) # load got pointer
add r2,r2,r3
bl save_regs_r3_r12
bl .rtas_init
bl restore_regs_r3_r12
ld r11,72(r1) # restore msr value
ld r2,64(r1) # restore toc
ld r1,0(r1) # get old stack
mtmsrd r11 # restore msr
isync
# Return rtas entry
ld r4,._rtas_entry_offset-_rtas_start(r8)
add r3,r3,r4
mtlr r10
blr
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