u-boot/arch/arm/cpu/armv8/transition.S
Alison Wang 3db86f4bbd armv8: fsl-layerscape: Support loading 32-bit OS with PSCI enabled
As PSCI and secure monitor firmware framework are enabled, this patch is
to support loading 32-bit OS in such case. The default target exception
level returned to U-Boot is EL2, so the corresponding work to switch to
AArch32 EL2 and jump to 32-bit OS are done in U-Boot and secure firmware
together.

Signed-off-by: Alison Wang <alison.wang@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
2016-11-22 11:40:24 -08:00

46 lines
959 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:
cmp x4, #ES_TO_AARCH64
b.eq 2f
/*
* When loading 32-bit kernel, it will jump
* to secure firmware again, and never return.
*/
bl armv8_el2_to_aarch32
2:
/*
* 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)
WEAK(armv8_el2_to_aarch32)
ret
ENDPROC(armv8_el2_to_aarch32)