linux-stable/arch/xtensa/boot/boot-elf/bootstrap.S
Max Filippov 09af39f649 xtensa: use register window specific opcodes only when present
xtensa core may be configured without register windows support, don't
use register window specific opcodes in that case. Use window register
specific opcodes to initialize hardware or reset core to a known state
regardless of the chosen ABI.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-10-18 22:19:35 -07:00

79 lines
1.4 KiB
ArmAsm

/*
* arch/xtensa/boot/boot-elf/bootstrap.S
*
* Low-level exception handling
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2004 - 2013 by Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
* Marc Gauthier <marc@tensilica.com>
* Piet Delaney <piet@tensilica.com>
*/
#include <asm/bootparam.h>
#include <asm/initialize_mmu.h>
#include <asm/vectors.h>
#include <linux/linkage.h>
.section .ResetVector.text, "ax"
.global _ResetVector
.global reset
_ResetVector:
_j _SetupMMU
.begin no-absolute-literals
.literal_position
#ifdef CONFIG_PARSE_BOOTPARAM
.align 4
_bootparam:
.short BP_TAG_FIRST
.short 4
.long BP_VERSION
.short BP_TAG_LAST
.short 0
.long 0
#endif
.align 4
_SetupMMU:
#if XCHAL_HAVE_WINDOWED
movi a0, 0
wsr a0, windowbase
rsync
movi a0, 1
wsr a0, windowstart
rsync
#endif
movi a0, 0x1F
wsr a0, ps
rsync
#ifndef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
initialize_mmu
#endif
rsil a0, XCHAL_DEBUGLEVEL-1
rsync
reset:
#if defined(CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) && \
XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY
movi a0, CONFIG_KERNEL_LOAD_ADDRESS
#else
movi a0, KERNELOFFSET
#endif
#ifdef CONFIG_PARSE_BOOTPARAM
movi a2, _bootparam
#else
movi a2, 0
#endif
movi a3, 0
movi a4, 0
jx a0
.end no-absolute-literals