xref: /OK3568_Linux_fs/u-boot/arch/arm/cpu/armv8/transition.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/*
2*4882a593Smuzhiyun * (C) Copyright 2013
3*4882a593Smuzhiyun * David Feng <fenghua@phytium.com.cn>
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * SPDX-License-Identifier:	GPL-2.0+
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun#include <asm-offsets.h>
9*4882a593Smuzhiyun#include <config.h>
10*4882a593Smuzhiyun#include <linux/linkage.h>
11*4882a593Smuzhiyun#include <asm/macro.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun.pushsection .text.armv8_switch_to_el2, "ax"
14*4882a593SmuzhiyunENTRY(armv8_switch_to_el2)
15*4882a593Smuzhiyun	switch_el x6, 1f, 0f, 0f
16*4882a593Smuzhiyun0:
17*4882a593Smuzhiyun	cmp x5, #ES_TO_AARCH64
18*4882a593Smuzhiyun	b.eq 2f
19*4882a593Smuzhiyun	/*
20*4882a593Smuzhiyun	 * When loading 32-bit kernel, it will jump
21*4882a593Smuzhiyun	 * to secure firmware again, and never return.
22*4882a593Smuzhiyun	 */
23*4882a593Smuzhiyun	bl armv8_el2_to_aarch32
24*4882a593Smuzhiyun2:
25*4882a593Smuzhiyun	/*
26*4882a593Smuzhiyun	 * x4 is kernel entry point or switch_to_el1
27*4882a593Smuzhiyun	 * if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
28*4882a593Smuzhiyun         * When running in EL2 now, jump to the
29*4882a593Smuzhiyun	 * address saved in x4.
30*4882a593Smuzhiyun	 */
31*4882a593Smuzhiyun	br x4
32*4882a593Smuzhiyun1:	armv8_switch_to_el2_m x4, x5, x6
33*4882a593SmuzhiyunENDPROC(armv8_switch_to_el2)
34*4882a593Smuzhiyun.popsection
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun.pushsection .text.armv8_switch_to_el1, "ax"
37*4882a593SmuzhiyunENTRY(armv8_switch_to_el1)
38*4882a593Smuzhiyun	switch_el x6, 0f, 1f, 0f
39*4882a593Smuzhiyun0:
40*4882a593Smuzhiyun	/* x4 is kernel entry point. When running in EL1
41*4882a593Smuzhiyun	 * now, jump to the address saved in x4.
42*4882a593Smuzhiyun	 */
43*4882a593Smuzhiyun	br x4
44*4882a593Smuzhiyun1:	armv8_switch_to_el1_m x4, x5, x6
45*4882a593SmuzhiyunENDPROC(armv8_switch_to_el1)
46*4882a593Smuzhiyun.popsection
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun.pushsection .text.armv8_el2_to_aarch32, "ax"
49*4882a593SmuzhiyunWEAK(armv8_el2_to_aarch32)
50*4882a593Smuzhiyun	ret
51*4882a593SmuzhiyunENDPROC(armv8_el2_to_aarch32)
52*4882a593Smuzhiyun.popsection
53