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/*
* arch/mips/dec/boot.S
*
* Copyright (C) 1995, 1996 Paul M. Antoine
*
* Written by Ralf Baechle and Andreas Busse, modified for DECStation
* support by Paul Antoine.
*
* NOTE: There are references to R4X00 code in here, because there is an
* upgrade module for Personal DECStations with such a CPU!
*/
#include <asm/asm.h>
#include <asm/regdef.h>
#include <asm/fpregdef.h>
#include <asm/mipsconfig.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/bootinfo.h>
/*
* dec_entry: Called by the boot PROM loader to do DECStation setup, prior
* to calling dec_setup() to fill in the boot_info structure.
*
* This code should also go in the boot loader for loading off
* floppy and HD... in addition to the tags code in dec_setup().
*
* FIXME: arrange for this code only to be linked in when building a
* kernel image to be booted via tftp from the boot prom??
*/
.text
.globl dec_entry
dec_entry:
/* Save the address of the REX call vector for later
* use in printing debug messages.
*/
sw a3,pmax_rex_base
sw a2,rex_prom_magic
la a0,dec_signon
jal pmax_printf
nop
/* Now set up the bootinfo with things that
* should be loaded by the boot loader, except that
* for the moment we're booting using tftp.
*/
jal dec_setup
nop
/*
* Now we need to move exception vector handler routines that appear
* in head.S down to the right addresses, 'cos the DECStation loads
* kernels at 0x80030000... <sigh>
*/
/*
* First move the TLB refill code down to offset 0x000, at addr 0x80000000
*/
la t0,except_vec0 # begining of exception code
la t1,except_vec1 # end of exception code
la t2,0x80000000 # where the code should live
lw t3,(t0) # get first word
1: sw t3,(t2) # put it where it should go
addiu t0,4 # increment both pointers
addiu t2,4
lw t3,(t0) # will be in the delay slot
bne t0,t1,1b
/*
* Now move the General Exception code down to offset 0x080 at 0x80000000
*/
la t0,except_vec3 # begining of general exception code
la t1,end_except # end of general exception code
la t2,0x80000080 # where the code should live
lw t3,(t0) # get first word
1: sw t3,(t2)
addiu t0,4
addiu t2,4
lw t3,(t0)
bne t0,t1,1b
la a0,dec_launch # say where we are going
jal pmax_printf
nop
la t0,mach_mem_upper # get upper memory bound
lw a0,(t0)
j kernel_entry
nop
.data
.align 2
dec_signon: .ascii "\n\nLinux/MIPS DECStation Boot\n";
.asciiz "Copyright (C) Paul M. Antoine 1995, 1996 and others, 1994, 1995, 1996\n\n";
dec_launch: .asciiz "Setup complete, launching kernel...\n";
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