coreboot-kgpe-d16/payloads/libpayload/arch/mips/head.S
Patrick Georgi a73b93157f tree: drop last paragraph of GPL copyright header
It encourages users from writing to the FSF without giving an address.
Linux also prefers to drop that and their checkpatch.pl (that we
imported) looks out for that.

This is the result of util/scripts/no-fsf-addresses.sh with no further
editing.

Change-Id: Ie96faea295fe001911d77dbc51e9a6789558fbd6
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/11888
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2015-10-31 21:37:39 +01:00

106 lines
2 KiB
ArmAsm

/*
* This file is part of the libpayload project.
*
* Copyright (C) 2014 Imagination Technologies
*
* 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.
*/
#include <arch/cpu.h>
/* Disable interrupts and mark the kernel mode */
.macro setup_c0_status clr
.set push
mfc0 $t0, $CP0_STATUS
or $t0, ST0_CU0 | 0x1f | \clr
xor $t0, 0x1f | \clr
mtc0 $t0, $CP0_STATUS
.set noreorder
sll $zero, 3
.set pop
.endm
/* Don't reorder instructions */
.set noreorder
.align 4
.global cb_header_ptr
cb_header_ptr:
.word 0
.global old_sp
old_sp:
.word 0
.global _entry, _leave
.text
/* Our entry point */
_entry:
/*
* This function saves off the previous stack and switches us to our
* own execution environment.
*/
/* Clear watch and cause registers */
mtc0 $zero, $CP0_WATCHLO
mtc0 $zero, $CP0_WATCHHI
mtc0 $zero, $CP0_CAUSE
/* Disable interrupts */
setup_c0_status 0
/* Don't use at in synthetic instr. */
.set noat
/* Init timer */
mtc0 $zero, $CP0_COUNT
mtc0 $zero, $CP0_COMPARE
/* Initialize $gp */
bal 1f
nop
.word _gp
1:
lw $gp, 0($ra)
/* Clear .bss: start_bss = _edata, end_bss = _end */
la $t0, _edata
sw $zero, ($t0)
la $t1, _end - 4
clear_bss:
addiu $t0, 4
sw $zero, ($t0)
bne $t0, $t1, clear_bss
nop
/* Save off the location of the coreboot tables */
la $at, cb_header_ptr
sw $a0, 0x00($at)
/* Save old stack pointer */
la $at, old_sp
sw $sp, 0x00($at)
/* Setup new stack */
la $sp, _stack
/* Let's rock */
la $a2, start_main
jalr $a2
nop
_leave:
/* Restore old stack. */
lw $sp, old_sp
/* Return to the original context. */
eret