The back-to-bootrom implementation for Rockchip has always relied on the stack-pointer being valid on entry, so there was little reason to have this as an assembly implementation.
This provides a new C-only implementation of save_boot_params and back_to_bootrom (relying on setjmp/longjmp) and removes the older assembly-only implementation.
Signed-off-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com ---
arch/arm/include/asm/arch-rockchip/bootrom.h | 27 ++++++++--- arch/arm/mach-rockchip/Makefile | 4 +- arch/arm/mach-rockchip/bootrom.c | 52 ++++++++++++++++++++- arch/arm/mach-rockchip/save_boot_param.S | 69 ---------------------------- 4 files changed, 73 insertions(+), 79 deletions(-) delete mode 100644 arch/arm/mach-rockchip/save_boot_param.S
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 169cc5e..2f61a33 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -1,5 +1,6 @@ /* * (C) Copyright 2017 Heiko Stuebner heiko@sntech.de + * (C) Copyright 2017 Theobroma Systems Design und Consulting GmbH * * SPDX-License-Identifier: GPL-2.0 */ @@ -14,15 +15,27 @@ extern u32 SAVE_SP_ADDR;
/** - * Hand control back to the bootrom to load another - * boot stage. + * back_to_bootrom() - return to bootrom (for TPL/SPL), passing a + * result code + * + * Transfer control back to the Rockchip BROM, restoring necessary + * register context and passing a command/result code to the BROM + * to instruct its next actions (e.g. continue boot sequence, enter + * download mode, ...). + * + * This function does not return. */ -void back_to_bootrom(void); +enum rockchip_bootrom_cmd { + /* + * These can not start at 0, as 0 has a special meaning + * for setjmp(). + */
-/** - * Assembler component for the above (do not call this directly) - */ -void _back_to_bootrom_s(void); + BROM_BOOT_NEXTSTAGE = 1, /* continue boot-sequence */ + BROM_BOOT_ENTER_DNL, /* have BROM enter download-mode */ +}; + +void back_to_bootrom(void);
/** * Boot-device identifiers as used by the BROM diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile index 79e9704..f8b23ea 100644 --- a/arch/arm/mach-rockchip/Makefile +++ b/arch/arm/mach-rockchip/Makefile @@ -8,8 +8,8 @@ # this may have entered from ATF with the stack-pointer pointing to # inaccessible/protected memory (and the bootrom-helper assumes that # the stack-pointer is valid before switching to the U-Boot stack). -obj-spl-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o save_boot_param.o -obj-tpl-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o save_boot_param.o +obj-spl-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o +obj-tpl-$(CONFIG_ROCKCHIP_BROM_HELPER) += bootrom.o
obj-tpl-$(CONFIG_ROCKCHIP_RK3188) += rk3188-board-tpl.o obj-tpl-$(CONFIG_ROCKCHIP_RK3368) += rk3368-board-tpl.o diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..7b9b307 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -6,11 +6,61 @@
#include <common.h> #include <asm/arch/bootrom.h> +#include <asm/setjmp.h> +#include <asm/system.h> + +/* + * Force the jmp_buf to the data-section, as .bss will not be valid + * when save_boot_params is invoked. + */ +static jmp_buf brom_ctx __section(".data");
void back_to_bootrom(void) { #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif - _back_to_bootrom_s(); + longjmp(brom_ctx, BROM_BOOT_NEXTSTAGE); +} + +/* + * All Rockchip BROM implementations enter with a valid stack-pointer, + * so this can safely be implemented in C (providing a single + * implementation both for ARMv7 and AArch64). + */ +int save_boot_params(void) +{ + int ret = setjmp(brom_ctx); + + switch (ret) { + case 0: + /* + * This is the initial pass through this function + * (i.e. saving the context), setjmp just setup up the + * brom_ctx: transfer back into the startup-code at + * 'save_boot_params_ret' and let the compiler know + * that this will not return. + */ + save_boot_params_ret(); + while (true) + /* does not return */; + break; + + case BROM_BOOT_NEXTSTAGE: + /* + * To instruct the BROM to boot the next stage, we + * need to return 0 to it: i.e. we need to rewrite + * the return code once more. + */ + ret = 0; + break; + + default: +#if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) + puts("FATAL: unexpected command to back_to_bootrom()\n"); +#endif + hang(); + }; + + return ret; } diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S deleted file mode 100644 index 50fce20..0000000 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ /dev/null @@ -1,69 +0,0 @@ -/* - * (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, #0x60 - 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, #0x60 - mov x0, xzr - ret -ENDPROC(_back_to_bootrom_s) -#else -.globl SAVE_SP_ADDR -SAVE_SP_ADDR: - .word 0 - -/* - * void save_boot_params - * - * Save sp, lr, r1~r12 - */ -ENTRY(save_boot_params) - push {r1-r12, lr} - ldr r0, =SAVE_SP_ADDR - str sp, [r0] - b save_boot_params_ret @ back to my caller -ENDPROC(save_boot_params) - - -.globl _back_to_bootrom_s -ENTRY(_back_to_bootrom_s) - ldr r0, =SAVE_SP_ADDR - ldr sp, [r0] - mov r0, #0 - pop {r1-r12, pc} -ENDPROC(_back_to_bootrom_s) -#endif