freebsd-dev/stand/powerpc/uboot/start.S
2017-11-14 23:02:19 +00:00

95 lines
2.5 KiB
ArmAsm

/*-
* Copyright (c) 2007 Semihalf, Rafal Jaworowski <raj@semihalf.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asm.h>
/*
* Entry point to the loader that U-Boot passes control to.
*/
.text
.globl _start
_start:
/* Hint where to look for the API signature */
lis %r11, uboot_address@ha
addi %r11, %r11, uboot_address@l
stw %r1, 0(%r11)
/* Save U-Boot's r14 */
lis %r11, saved_regs@ha
addi %r11, %r11, saved_regs@l
stw %r14, 0(%r11)
/* Disable interrupts */
mfmsr %r11
andi. %r11, %r11, ~0x8000@l
mtmsr %r11
b main
/*
* syscall()
*/
ENTRY(syscall)
stwu %r1, -16(%r1)
mflr %r0
stw %r14, 8(%r1)
stw %r0, 20(%r1)
/* Restore U-Boot's r14 */
lis %r11, saved_regs@ha
addi %r11, %r11, saved_regs@l
lwz %r14, 0(%r11)
/* Enable interrupts */
mfmsr %r11
ori %r11, %r11, 0x8000@l
mtmsr %r11
/* Call into U-Boot */
lis %r11, syscall_ptr@ha
addi %r11, %r11, syscall_ptr@l
lwz %r11, 0(%r11)
mtctr %r11
bctrl
/* Disable interrupts */
mfmsr %r11
andi. %r11, %r11, ~0x8000@l
mtmsr %r11
/* Epilogue */
lwz %r11, 0(%r1)
lwz %r0, 4(%r11)
mtlr %r0
lwz %r14, 8(%r1)
mr %r1, %r11
blr
/*
* Data section
*/
.data
GLOBAL(syscall_ptr)
.long 0
GLOBAL(saved_regs)
.long 0 /* R14 */
GLOBAL(uboot_address)
.long 0