The back-to-bootrom support for Rockchip is equivalent to an (assembly) implementation of setjmp/longjmp (i.e. it saves the stack-pointer, link-register and callee-saved registers). Up until now, this had only been implemented for AArch32 (i.e. ARMv7 or older), which puts the new ARMv8 devices (which boot in AArch64 mode) at a slight disadvantage.
To allow use of the 'back-to-bootrom' feature on new devices (e.g. the RK3368), this commit adds an implementation for AArch64.
Signed-off-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com ---
arch/arm/mach-rockchip/save_boot_param.S | 37 ++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 5e6c8db..945a9dd 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -1,11 +1,47 @@ /* * (C) Copyright 2016 Rockchip Electronics Co., Ltd + * (C) Copyright 2017 Theobroma Systems Design und Consulting GmbH * * SPDX-License-Identifier: GPL-2.0+ */
#include <linux/linkage.h>
+#if defined(CONFIG_ARM64) +.globl SAVE_SP_ADDR +SAVE_SP_ADDR: + .quad 0 + +ENTRY(save_boot_params) + sub sp, sp, #0x100 + stp x29, x30, [sp, #0x50] + stp x27, x28, [sp, #0x40] + stp x25, x26, [sp, #0x30] + stp x23, x24, [sp, #0x20] + stp x21, x22, [sp, #0x10] + stp x19, x20, [sp, #0] + ldr x8, =SAVE_SP_ADDR + mov x9, sp + str x9, [x8] + b save_boot_params_ret /* back to my caller */ +ENDPROC(save_boot_params) + +.globl _back_to_bootrom_s +ENTRY(_back_to_bootrom_s) + ldr x0, =SAVE_SP_ADDR + ldr x0, [x0] + mov sp, x0 + ldp x29, x30, [sp, #0x50] + ldp x27, x28, [sp, #0x40] + ldp x25, x26, [sp, #0x30] + ldp x23, x24, [sp, #0x20] + ldp x21, x22, [sp, #0x10] + ldp x19, x20, [sp] + add sp, sp, #0x100 + mov x0, xzr + ret +ENDPROC(_back_to_bootrom_s) +#else .globl SAVE_SP_ADDR SAVE_SP_ADDR: .word 0 @@ -30,3 +66,4 @@ ENTRY(_back_to_bootrom_s) mov r0, #0 pop {r1-r12, pc} ENDPROC(_back_to_bootrom_s) +#endif