u-boot-brain/arch/arm/cpu/armv8/transition.S
Alison Wang ec6617c397 armv8: Support loading 32-bit OS in AArch32 execution state
To support loading a 32-bit OS, the execution state will change from
AArch64 to AArch32 when jumping to kernel.

The architecture information will be got through checking FIT image,
then U-Boot will load 32-bit OS or 64-bit OS automatically.

Signed-off-by: Ebony Zhu <ebony.zhu@nxp.com>
Signed-off-by: Alison Wang <alison.wang@nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.zhao@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
2016-11-22 11:40:24 -08:00

35 lines
733 B
ArmAsm

/*
* (C) Copyright 2013
* David Feng <fenghua@phytium.com.cn>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <asm-offsets.h>
#include <config.h>
#include <linux/linkage.h>
#include <asm/macro.h>
ENTRY(armv8_switch_to_el2)
switch_el x5, 1f, 0f, 0f
0:
/*
* x3 is kernel entry point or switch_to_el1
* if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
* When running in EL2 now, jump to the
* address saved in x3.
*/
br x3
1: armv8_switch_to_el2_m x3, x4, x5
ENDPROC(armv8_switch_to_el2)
ENTRY(armv8_switch_to_el1)
switch_el x5, 0f, 1f, 0f
0:
/* x3 is kernel entry point. When running in EL1
* now, jump to the address saved in x3.
*/
br x3
1: armv8_switch_to_el1_m x3, x4, x5
ENDPROC(armv8_switch_to_el1)