[U-Boot] [PATCH] rockchip: add support for backing to bootrom download mode
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
Signed-off-by: Andy Yan andy.yan@rock-chips.com ---
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 92eb878..6ae3e94 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -22,6 +22,6 @@ void back_to_bootrom(void); /** * Assembler component for the above (do not call this directly) */ -void _back_to_bootrom_s(void); +void _back_to_bootrom_s(int mode);
#endif diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index d9b25d5..3ab0c30 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -113,6 +113,7 @@ config ROCKCHIP_RK3399 select SPL_SERIAL_SUPPORT select SPL_DRIVERS_MISC_SUPPORT select ENABLE_ARM_SOC_BOOT0_HOOK + select ROCKCHIP_BROM_HELPER select DEBUG_UART_BOARD_INIT help The Rockchip RK3399 is a ARM-based SoC with a dual-core Cortex-A72 @@ -149,6 +150,18 @@ config TPL_ROCKCHIP_BACK_TO_BROM SPL will return to the boot rom, which will then load the U-Boot binary to keep going on.
+config ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG + hex "Bootrom download mode flag register address" + default 0x200081c8 if ROCKCHIP_RK3036 + default 0xff730094 if ROCKCHIP_RK3288 + default 0xff738200 if ROCKCHIP_RK3368 + default 0xff320300 if ROCKCHIP_RK3399 + default 0x10300580 if ROCKCHIP_RV1108 + default 0x00 + help + The Soc will return to bootrom download mode if this register set + to BOOTROM_DOWNLOAD_FLAG. + config ROCKCHIP_SPL_RESERVE_IRAM hex "Size of IRAM reserved in SPL" default 0x4000 diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..6f0d583 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -12,5 +12,5 @@ void back_to_bootrom(void) #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif - _back_to_bootrom_s(); + _back_to_bootrom_s(0); } diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 50fce20..f1bed0b 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -7,11 +7,25 @@
#include <linux/linkage.h>
+#define BACK_TO_BROM_DOWNLOAD_FLAG 0xEF08A53C + #if defined(CONFIG_ARM64) .globl SAVE_SP_ADDR SAVE_SP_ADDR: .quad 0
+ENTRY(check_back_to_brom_dnl_flag) + ldr x8, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG + ldr x9, [x8] + ldr x0, =BACK_TO_BROM_DOWNLOAD_FLAG + cmp x9, x0 + b.ne save_boot_params_ret + mov x9, xzr + str x9, [x8] /* clear flag */ + mov x0, #1 /* indicate the bootrom to enter download mode */ + b _back_to_bootrom_s +ENDPROC(check_back_to_brom_dnl_flag) + ENTRY(save_boot_params) sub sp, sp, #0x60 stp x29, x30, [sp, #0x50] @@ -23,14 +37,22 @@ ENTRY(save_boot_params) ldr x8, =SAVE_SP_ADDR mov x9, sp str x9, [x8] +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG + b check_back_to_brom_dnl_flag +#else b save_boot_params_ret /* back to my caller */ +#endif ENDPROC(save_boot_params)
+/* + * x0: return value for bootrom, none-zero for bootrom download + * mode and zero for normal boot mode + */ .globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s) - ldr x0, =SAVE_SP_ADDR - ldr x0, [x0] - mov sp, x0 + ldr x1, =SAVE_SP_ADDR + ldr x1, [x1] + mov sp, x1 ldp x29, x30, [sp, #0x50] ldp x27, x28, [sp, #0x40] ldp x25, x26, [sp, #0x30] @@ -38,7 +60,6 @@ ENTRY(_back_to_bootrom_s) ldp x21, x22, [sp, #0x10] ldp x19, x20, [sp] add sp, sp, #0x60 - mov x0, xzr ret ENDPROC(_back_to_bootrom_s) #else @@ -46,6 +67,18 @@ ENDPROC(_back_to_bootrom_s) SAVE_SP_ADDR: .word 0
+ENTRY(check_back_to_brom_dnl_flag) + ldr r0, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG + ldr r1, [r0] + ldr r2, =BACK_TO_BROM_DOWNLOAD_FLAG + cmp r1, r2 + bne save_boot_params_ret + mov r3, #0 + str r3, [r0] @clear flag + mov r0, #1 @indicate the bootrom to enter download mode + b _back_to_bootrom_s +ENDPROC(check_back_to_brom_dnl_flag) + /* * void save_boot_params * @@ -55,15 +88,21 @@ 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 +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG + b check_back_to_brom_dnl_flag +#else + b save_boot_params_ret +#endif ENDPROC(save_boot_params)
- +/* + * r0: return value for bootrom, none-zero for bootrom download + * mode and zero for normal boot mode + */ .globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s) - ldr r0, =SAVE_SP_ADDR - ldr sp, [r0] - mov r0, #0 + ldr r1, =SAVE_SP_ADDR + ldr sp, [r1] pop {r1-r12, pc} ENDPROC(_back_to_bootrom_s) #endif
Hi Andy,
On 09/11/2017 02:27 PM, Andy Yan wrote:
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
Signed-off-by: Andy Yan andy.yan@rock-chips.com
It looks good to me, Reviewed-by: Kever Yang kever.yang@rock-chips.com
Thanks, - Kever
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 92eb878..6ae3e94 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -22,6 +22,6 @@ void back_to_bootrom(void); /**
- Assembler component for the above (do not call this directly)
*/ -void _back_to_bootrom_s(void); +void _back_to_bootrom_s(int mode);
#endif diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index d9b25d5..3ab0c30 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -113,6 +113,7 @@ config ROCKCHIP_RK3399 select SPL_SERIAL_SUPPORT select SPL_DRIVERS_MISC_SUPPORT select ENABLE_ARM_SOC_BOOT0_HOOK
- select ROCKCHIP_BROM_HELPER select DEBUG_UART_BOARD_INIT help The Rockchip RK3399 is a ARM-based SoC with a dual-core Cortex-A72
@@ -149,6 +150,18 @@ config TPL_ROCKCHIP_BACK_TO_BROM SPL will return to the boot rom, which will then load the U-Boot binary to keep going on.
+config ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- hex "Bootrom download mode flag register address"
- default 0x200081c8 if ROCKCHIP_RK3036
- default 0xff730094 if ROCKCHIP_RK3288
- default 0xff738200 if ROCKCHIP_RK3368
- default 0xff320300 if ROCKCHIP_RK3399
- default 0x10300580 if ROCKCHIP_RV1108
- default 0x00
- help
The Soc will return to bootrom download mode if this register setto BOOTROM_DOWNLOAD_FLAG.- config ROCKCHIP_SPL_RESERVE_IRAM hex "Size of IRAM reserved in SPL" default 0x4000
diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..6f0d583 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -12,5 +12,5 @@ void back_to_bootrom(void) #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif
- _back_to_bootrom_s();
- _back_to_bootrom_s(0); }
diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 50fce20..f1bed0b 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -7,11 +7,25 @@
#include <linux/linkage.h>
+#define BACK_TO_BROM_DOWNLOAD_FLAG 0xEF08A53C
- #if defined(CONFIG_ARM64) .globl SAVE_SP_ADDR SAVE_SP_ADDR: .quad 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr x8, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr x9, [x8]
- ldr x0, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp x9, x0
- b.ne save_boot_params_ret
- mov x9, xzr
- str x9, [x8] /* clear flag */
- mov x0, #1 /* indicate the bootrom to enter download mode */
- b _back_to_bootrom_s
+ENDPROC(check_back_to_brom_dnl_flag)
- ENTRY(save_boot_params) sub sp, sp, #0x60 stp x29, x30, [sp, #0x50]
@@ -23,14 +37,22 @@ ENTRY(save_boot_params) ldr x8, =SAVE_SP_ADDR mov x9, sp str x9, [x8] +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else b save_boot_params_ret /* back to my caller */ +#endif ENDPROC(save_boot_params)
+/*
- x0: return value for bootrom, none-zero for bootrom download
mode and zero for normal boot mode- */ .globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr x0, =SAVE_SP_ADDR
- ldr x0, [x0]
- mov sp, x0
- ldr x1, =SAVE_SP_ADDR
- ldr x1, [x1]
- mov sp, x1 ldp x29, x30, [sp, #0x50] ldp x27, x28, [sp, #0x40] ldp x25, x26, [sp, #0x30]
@@ -38,7 +60,6 @@ ENTRY(_back_to_bootrom_s) ldp x21, x22, [sp, #0x10] ldp x19, x20, [sp] add sp, sp, #0x60
- mov x0, xzr ret ENDPROC(_back_to_bootrom_s) #else
@@ -46,6 +67,18 @@ ENDPROC(_back_to_bootrom_s) SAVE_SP_ADDR: .word 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr r0, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr r1, [r0]
- ldr r2, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp r1, r2
- bne save_boot_params_ret
- mov r3, #0
- str r3, [r0] @clear flag
- mov r0, #1 @indicate the bootrom to enter download mode
- b _back_to_bootrom_s
+ENDPROC(check_back_to_brom_dnl_flag)
- /*
- void save_boot_params
@@ -55,15 +88,21 @@ 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
+#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else
- b save_boot_params_ret
+#endif ENDPROC(save_boot_params)
+/*
- r0: return value for bootrom, none-zero for bootrom download
mode and zero for normal boot mode- */ .globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr r0, =SAVE_SP_ADDR
- ldr sp, [r0]
- mov r0, #0
- ldr r1, =SAVE_SP_ADDR
- ldr sp, [r1] pop {r1-r12, pc} ENDPROC(_back_to_bootrom_s) #endif
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
Signed-off-by: Andy Yan andy.yan@rock-chips.com Reviewed-by: Kever Yang kever.yang@rock-chips.com
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
Acked-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com
On Mon, 11 Sep 2017, Andy Yan wrote:
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
I was not aware that the TPL/SPL overrides interrupt settings. What exactly does this comment refer to?
Signed-off-by: Andy Yan andy.yan@rock-chips.com Reviewed-by: Kever Yang kever.yang@rock-chips.com Acked-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 92eb878..6ae3e94 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -22,6 +22,6 @@ void back_to_bootrom(void); /**
- Assembler component for the above (do not call this directly)
*/ -void _back_to_bootrom_s(void); +void _back_to_bootrom_s(int mode);
Please add documentation for externally visible functions.
#endif diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index d9b25d5..3ab0c30 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -113,6 +113,7 @@ config ROCKCHIP_RK3399 select SPL_SERIAL_SUPPORT select SPL_DRIVERS_MISC_SUPPORT select ENABLE_ARM_SOC_BOOT0_HOOK
- select ROCKCHIP_BROM_HELPER select DEBUG_UART_BOARD_INIT help The Rockchip RK3399 is a ARM-based SoC with a dual-core Cortex-A72
@@ -149,6 +150,18 @@ config TPL_ROCKCHIP_BACK_TO_BROM SPL will return to the boot rom, which will then load the U-Boot binary to keep going on.
+config ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- hex "Bootrom download mode flag register address"
- default 0x200081c8 if ROCKCHIP_RK3036
- default 0xff730094 if ROCKCHIP_RK3288
- default 0xff738200 if ROCKCHIP_RK3368
- default 0xff320300 if ROCKCHIP_RK3399
- default 0x10300580 if ROCKCHIP_RV1108
- default 0x00
If this is not user-configurable (i.e. if it is a per-chip constant), we should define this in a header file. I would suggest to do the detection/mapping either in include/asm/arch-rockchip/bootrom.h or in a cpu-specific header that gets included from there.
- help
The Soc will return to bootrom download mode if this register setto BOOTROM_DOWNLOAD_FLAG.
Documenting here what BOOTROM_DOWNLOAD_FLAG is or where it can be found would be very helpful to anyone coming across this in the future.
config ROCKCHIP_SPL_RESERVE_IRAM hex "Size of IRAM reserved in SPL" default 0x4000 diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..6f0d583 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -12,5 +12,5 @@ void back_to_bootrom(void) #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif
- _back_to_bootrom_s();
- _back_to_bootrom_s(0);
} diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 50fce20..f1bed0b 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -7,11 +7,25 @@
#include <linux/linkage.h>
+#define BACK_TO_BROM_DOWNLOAD_FLAG 0xEF08A53C
This looks like it should be defined in bootrom.h
#if defined(CONFIG_ARM64) .globl SAVE_SP_ADDR SAVE_SP_ADDR: .quad 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr x8, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr x9, [x8]
- ldr x0, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp x9, x0
- b.ne save_boot_params_ret
- mov x9, xzr
- str x9, [x8] /* clear flag */
- mov x0, #1 /* indicate the bootrom to enter download mode */
- b _back_to_bootrom_s
How does this ever get entered? If the download flag is already set prior to this code being executed, then the BROM would certainly not even come here?
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
+ENDPROC(check_back_to_brom_dnl_flag)
ENTRY(save_boot_params) sub sp, sp, #0x60 stp x29, x30, [sp, #0x50] @@ -23,14 +37,22 @@ ENTRY(save_boot_params) ldr x8, =SAVE_SP_ADDR mov x9, sp str x9, [x8] +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else b save_boot_params_ret /* back to my caller */ +#endif
Please avoid the #if #else #endif here. Could you simply call into a function that handles this correctly for both cases?
However, this should fold back onto just the save_boot_params case anyway, if you can implement the checking function in C (as suggested above).
ENDPROC(save_boot_params)
+/*
- x0: return value for bootrom, none-zero for bootrom download
typo: non-zero
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr x0, =SAVE_SP_ADDR
- ldr x0, [x0]
- mov sp, x0
- ldr x1, =SAVE_SP_ADDR
- ldr x1, [x1]
- mov sp, x1 ldp x29, x30, [sp, #0x50] ldp x27, x28, [sp, #0x40] ldp x25, x26, [sp, #0x30]
@@ -38,7 +60,6 @@ ENTRY(_back_to_bootrom_s) ldp x21, x22, [sp, #0x10] ldp x19, x20, [sp] add sp, sp, #0x60
- mov x0, xzr ret
ENDPROC(_back_to_bootrom_s) #else @@ -46,6 +67,18 @@ ENDPROC(_back_to_bootrom_s) SAVE_SP_ADDR: .word 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr r0, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr r1, [r0]
- ldr r2, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp r1, r2
- bne save_boot_params_ret
- mov r3, #0
- str r3, [r0] @clear flag
- mov r0, #1 @indicate the bootrom to enter download mode
- b _back_to_bootrom_s
+ENDPROC(check_back_to_brom_dnl_flag)
See above: should be possible to do in C.
/*
- void save_boot_params
@@ -55,15 +88,21 @@ 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
+#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else
- b save_boot_params_ret
+#endif
See above.
ENDPROC(save_boot_params)
+/*
- r0: return value for bootrom, none-zero for bootrom download
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr r0, =SAVE_SP_ADDR
- ldr sp, [r0]
- mov r0, #0
- ldr r1, =SAVE_SP_ADDR
- ldr sp, [r1] pop {r1-r12, pc}
ENDPROC(_back_to_bootrom_s) #endif
Hi Philipp:
On 2017年09月13日 03:30, Philipp Tomsich wrote:
On Mon, 11 Sep 2017, Andy Yan wrote:
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
I was not aware that the TPL/SPL overrides interrupt settings. What exactly does this comment refer to?
For armv7, the VBAR and V in SCTLR(which should be 1 for rk3288 and zero for other arm32 platforms) are override in arch/cpu/armv7/start.S For armv8, I also find the VBAR related settings, but I didn't test it. I am not sure is there any other settings in the TPL/SPL startup code that will override the default setting in bootrom(maybe mmu, cache and other feathers added to the startup code in the future, this is out of control), but the VBAR and V are indeed override on arm32 platforms. So I think back to bootrom download mode if the flag is set before anything changed is a efficient way.
Signed-off-by: Andy Yan andy.yan@rock-chips.com Reviewed-by: Kever Yang kever.yang@rock-chips.com Acked-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 92eb878..6ae3e94 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -22,6 +22,6 @@ void back_to_bootrom(void); /**
- Assembler component for the above (do not call this directly)
*/ -void _back_to_bootrom_s(void); +void _back_to_bootrom_s(int mode);
Please add documentation for externally visible functions.
Okay.
#endif diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index d9b25d5..3ab0c30 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -113,6 +113,7 @@ config ROCKCHIP_RK3399 select SPL_SERIAL_SUPPORT select SPL_DRIVERS_MISC_SUPPORT select ENABLE_ARM_SOC_BOOT0_HOOK
- select ROCKCHIP_BROM_HELPER select DEBUG_UART_BOARD_INIT help The Rockchip RK3399 is a ARM-based SoC with a dual-core Cortex-A72
@@ -149,6 +150,18 @@ config TPL_ROCKCHIP_BACK_TO_BROM SPL will return to the boot rom, which will then load the U-Boot binary to keep going on.
+config ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- hex "Bootrom download mode flag register address"
- default 0x200081c8 if ROCKCHIP_RK3036
- default 0xff730094 if ROCKCHIP_RK3288
- default 0xff738200 if ROCKCHIP_RK3368
- default 0xff320300 if ROCKCHIP_RK3399
- default 0x10300580 if ROCKCHIP_RV1108
- default 0x00
If this is not user-configurable (i.e. if it is a per-chip constant), we should define this in a header file. I would suggest to do the detection/mapping either in include/asm/arch-rockchip/bootrom.h or in a cpu-specific header that gets included from there.
Actually this is user-configuarable, we just chose a register that not be used by the system to pass the boot mode flag. And we also have boards that don't want to enable this function, so they can set the register address to 0. then we will ship the mode check .
- help
The Soc will return to bootrom download mode if this register setto BOOTROM_DOWNLOAD_FLAG.Documenting here what BOOTROM_DOWNLOAD_FLAG is or where it can be found would be very helpful to anyone coming across this in the future.
okay
config ROCKCHIP_SPL_RESERVE_IRAM hex "Size of IRAM reserved in SPL" default 0x4000 diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..6f0d583 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -12,5 +12,5 @@ void back_to_bootrom(void) #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif
- _back_to_bootrom_s();
- _back_to_bootrom_s(0);
} diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 50fce20..f1bed0b 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -7,11 +7,25 @@
#include <linux/linkage.h>
+#define BACK_TO_BROM_DOWNLOAD_FLAG 0xEF08A53C
This looks like it should be defined in bootrom.h
It has been move to boot-mode.h in new version.
#if defined(CONFIG_ARM64) .globl SAVE_SP_ADDR SAVE_SP_ADDR: .quad 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr x8, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr x9, [x8]
- ldr x0, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp x9, x0
- b.ne save_boot_params_ret
- mov x9, xzr
- str x9, [x8] /* clear flag */
- mov x0, #1 /* indicate the bootrom to enter download
mode */
- b _back_to_bootrom_s
How does this ever get entered? If the download flag is already set prior to this code being executed, then the BROM would certainly not even come here?
BROM would not check the boot mode register, it only enter bootrom download mode if we return a non-zere value for it or it can't find a valid image from all the storage device.
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
We can't predict how many settings the TPL/SPL startup code changed now and future will affect the bootrom download function, So back to bootrom download mode before anything been changed is a simple way.
+ENDPROC(check_back_to_brom_dnl_flag)
ENTRY(save_boot_params) sub sp, sp, #0x60 stp x29, x30, [sp, #0x50] @@ -23,14 +37,22 @@ ENTRY(save_boot_params) ldr x8, =SAVE_SP_ADDR mov x9, sp str x9, [x8] +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else b save_boot_params_ret /* back to my caller */ +#endif
Please avoid the #if #else #endif here. Could you simply call into a function that handles this correctly for both cases?
I have to skip the check if the REG address is zero.
However, this should fold back onto just the save_boot_params case anyway, if you can implement the checking function in C (as suggested above).
Please see my explanation above.
ENDPROC(save_boot_params)
+/*
- x0: return value for bootrom, none-zero for bootrom download
typo: non-zero
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr x0, =SAVE_SP_ADDR
- ldr x0, [x0]
- mov sp, x0
- ldr x1, =SAVE_SP_ADDR
- ldr x1, [x1]
- mov sp, x1 ldp x29, x30, [sp, #0x50] ldp x27, x28, [sp, #0x40] ldp x25, x26, [sp, #0x30]
@@ -38,7 +60,6 @@ ENTRY(_back_to_bootrom_s) ldp x21, x22, [sp, #0x10] ldp x19, x20, [sp] add sp, sp, #0x60
- mov x0, xzr ret
ENDPROC(_back_to_bootrom_s) #else @@ -46,6 +67,18 @@ ENDPROC(_back_to_bootrom_s) SAVE_SP_ADDR: .word 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr r0, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr r1, [r0]
- ldr r2, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp r1, r2
- bne save_boot_params_ret
- mov r3, #0
- str r3, [r0] @clear flag
- mov r0, #1 @indicate the bootrom to enter download mode
- b _back_to_bootrom_s
+ENDPROC(check_back_to_brom_dnl_flag)
See above: should be possible to do in C.
/*
- void save_boot_params
@@ -55,15 +88,21 @@ 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
+#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else
- b save_boot_params_ret
+#endif
See above.
ENDPROC(save_boot_params)
+/*
- r0: return value for bootrom, none-zero for bootrom download
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr r0, =SAVE_SP_ADDR
- ldr sp, [r0]
- mov r0, #0
- ldr r1, =SAVE_SP_ADDR
- ldr sp, [r1] pop {r1-r12, pc}
ENDPROC(_back_to_bootrom_s) #endif
On 13 Sep 2017, at 03:23, Andy Yan andy.yan@rock-chips.com wrote:
Hi Philipp:
On 2017年09月13日 03:30, Philipp Tomsich wrote:
On Mon, 11 Sep 2017, Andy Yan wrote:
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
I was not aware that the TPL/SPL overrides interrupt settings. What exactly does this comment refer to?
For armv7, the VBAR and V in SCTLR(which should be 1 for rk3288 and zero for other arm32 platforms) are override in arch/cpu/armv7/start.S For armv8, I also find the VBAR related settings, but I didn't test it. I am not sure is there any other settings in the TPL/SPL startup code that will override the default setting in bootrom(maybe mmu, cache and other feathers added to the startup code in the future, this is out of control), but the VBAR and V are indeed override on arm32 platforms. So I think back to bootrom download mode if the flag is set before anything changed is a efficient way.
Should we save these flags as part of the "save_boot_params + back_to_bootrom_s” processing?
Signed-off-by: Andy Yan andy.yan@rock-chips.com Reviewed-by: Kever Yang kever.yang@rock-chips.com Acked-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 92eb878..6ae3e94 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -22,6 +22,6 @@ void back_to_bootrom(void); /**
- Assembler component for the above (do not call this directly)
*/ -void _back_to_bootrom_s(void); +void _back_to_bootrom_s(int mode);
Please add documentation for externally visible functions.
Okay.
#endif diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index d9b25d5..3ab0c30 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -113,6 +113,7 @@ config ROCKCHIP_RK3399 select SPL_SERIAL_SUPPORT select SPL_DRIVERS_MISC_SUPPORT select ENABLE_ARM_SOC_BOOT0_HOOK
- select ROCKCHIP_BROM_HELPER select DEBUG_UART_BOARD_INIT help The Rockchip RK3399 is a ARM-based SoC with a dual-core Cortex-A72
@@ -149,6 +150,18 @@ config TPL_ROCKCHIP_BACK_TO_BROM SPL will return to the boot rom, which will then load the U-Boot binary to keep going on.
+config ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- hex "Bootrom download mode flag register address"
- default 0x200081c8 if ROCKCHIP_RK3036
- default 0xff730094 if ROCKCHIP_RK3288
- default 0xff738200 if ROCKCHIP_RK3368
- default 0xff320300 if ROCKCHIP_RK3399
- default 0x10300580 if ROCKCHIP_RV1108
- default 0x00
If this is not user-configurable (i.e. if it is a per-chip constant), we should define this in a header file. I would suggest to do the detection/mapping either in include/asm/arch-rockchip/bootrom.h or in a cpu-specific header that gets included from there.
Actually this is user-configuarable, we just chose a register that not be used by the system to pass the boot mode flag. And we also have boards that don't want to enable this function, so they can set the register address to 0. then we will ship the mode check .
Understood.
- help
The Soc will return to bootrom download mode if this register setto BOOTROM_DOWNLOAD_FLAG.Documenting here what BOOTROM_DOWNLOAD_FLAG is or where it can be found would be very helpful to anyone coming across this in the future.
okay
config ROCKCHIP_SPL_RESERVE_IRAM hex "Size of IRAM reserved in SPL" default 0x4000 diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..6f0d583 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -12,5 +12,5 @@ void back_to_bootrom(void) #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif
- _back_to_bootrom_s();
- _back_to_bootrom_s(0);
} diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 50fce20..f1bed0b 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -7,11 +7,25 @@
#include <linux/linkage.h>
+#define BACK_TO_BROM_DOWNLOAD_FLAG 0xEF08A53C
This looks like it should be defined in bootrom.h
It has been move to boot-mode.h in new version.
#if defined(CONFIG_ARM64) .globl SAVE_SP_ADDR SAVE_SP_ADDR: .quad 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr x8, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr x9, [x8]
- ldr x0, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp x9, x0
- b.ne save_boot_params_ret
- mov x9, xzr
- str x9, [x8] /* clear flag */
- mov x0, #1 /* indicate the bootrom to enter download mode */
- b _back_to_bootrom_s
How does this ever get entered? If the download flag is already set prior to this code being executed, then the BROM would certainly not even come here?
BROM would not check the boot mode register, it only enter bootrom download mode if we return a non-zere value for it or it can't find a valid image from all the storage device.
We should document this somewhere. A comment in this code might be great to let everyone know why we are checking this here.
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
We can't predict how many settings the TPL/SPL startup code changed now and future will affect the bootrom download function, So back to bootrom download mode before anything been changed is a simple way.
Ok. I’d still like to have this in C. The only requirement for this will be having a valid stack-pointer, so we should be able to do this early (before the various initialisation runs). I think board_init_f() would be a suitable place.
+ENDPROC(check_back_to_brom_dnl_flag)
ENTRY(save_boot_params) sub sp, sp, #0x60 stp x29, x30, [sp, #0x50] @@ -23,14 +37,22 @@ ENTRY(save_boot_params) ldr x8, =SAVE_SP_ADDR mov x9, sp str x9, [x8] +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else b save_boot_params_ret /* back to my caller */ +#endif
Please avoid the #if #else #endif here. Could you simply call into a function that handles this correctly for both cases?
I have to skip the check if the REG address is zero.
Good idea. Having a check for zero would match exactly how you described the handling of the Kconfig variable. Note that you should document the special meaning of zero both in a comment and in the Kconfig help text.
However, this should fold back onto just the save_boot_params case anyway, if you can implement the checking function in C (as suggested above).
Please see my explanation above.
ENDPROC(save_boot_params)
+/*
- x0: return value for bootrom, none-zero for bootrom download
typo: non-zero
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr x0, =SAVE_SP_ADDR
- ldr x0, [x0]
- mov sp, x0
- ldr x1, =SAVE_SP_ADDR
- ldr x1, [x1]
- mov sp, x1 ldp x29, x30, [sp, #0x50] ldp x27, x28, [sp, #0x40] ldp x25, x26, [sp, #0x30]
@@ -38,7 +60,6 @@ ENTRY(_back_to_bootrom_s) ldp x21, x22, [sp, #0x10] ldp x19, x20, [sp] add sp, sp, #0x60
- mov x0, xzr ret
ENDPROC(_back_to_bootrom_s) #else @@ -46,6 +67,18 @@ ENDPROC(_back_to_bootrom_s) SAVE_SP_ADDR: .word 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr r0, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr r1, [r0]
- ldr r2, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp r1, r2
- bne save_boot_params_ret
- mov r3, #0
- str r3, [r0] @clear flag
- mov r0, #1 @indicate the bootrom to enter download mode
- b _back_to_bootrom_s
+ENDPROC(check_back_to_brom_dnl_flag)
See above: should be possible to do in C.
/*
- void save_boot_params
@@ -55,15 +88,21 @@ 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
+#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else
- b save_boot_params_ret
+#endif
See above.
ENDPROC(save_boot_params)
+/*
- r0: return value for bootrom, none-zero for bootrom download
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr r0, =SAVE_SP_ADDR
- ldr sp, [r0]
- mov r0, #0
- ldr r1, =SAVE_SP_ADDR
- ldr sp, [r1] pop {r1-r12, pc}
ENDPROC(_back_to_bootrom_s) #endif
Hi Philipp:
On 2017年09月13日 16:01, Dr. Philipp Tomsich wrote:
On 13 Sep 2017, at 03:23, Andy Yan <andy.yan@rock-chips.com mailto:andy.yan@rock-chips.com> wrote:
Hi Philipp:
On 2017年09月13日 03:30, Philipp Tomsich wrote:
On Mon, 11 Sep 2017, Andy Yan wrote:
Rockchip bootrom will enter download mode if it returns from spl/tpl with a none-zero value and couldn't find a valid image in the backup partition. This patch provide a method to instruct the system to back to bootrom download mode by checking the BROM_DOWNLOAD_FLAG register. As the bootrom download function relys on some modules such as interrupts, so we need to back to bootrom as early as possbile before the tpl/tps code override the interrupt settings.
I was not aware that the TPL/SPL overrides interrupt settings. What exactly does this comment refer to?
For armv7, the VBAR and V in SCTLR(which should be 1 for rk3288 and zero for other arm32 platforms) are override in arch/cpu/armv7/start.S For armv8, I also find the VBAR related settings, but I didn't test it. I am not sure is there any other settings in the TPL/SPL startup code that will override the default setting in bootrom(maybe mmu, cache and other feathers added to the startup code in the future, this is out of control), but the VBAR and V are indeed override on arm32 platforms. So I think back to bootrom download mode if the flag is set before anything changed is a efficient way.
Should we save these flags as part of the "save_boot_params + back_to_bootrom_s” processing?
Signed-off-by: Andy Yan <andy.yan@rock-chips.com mailto:andy.yan@rock-chips.com> Reviewed-by: Kever Yang <kever.yang@rock-chips.com mailto:kever.yang@rock-chips.com> Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com
mailto:philipp.tomsich@theobroma-systems.com>
arch/arm/include/asm/arch-rockchip/bootrom.h | 2 +- arch/arm/mach-rockchip/Kconfig | 13 +++++++ arch/arm/mach-rockchip/bootrom.c | 2 +- arch/arm/mach-rockchip/save_boot_param.S | 57 +++++++++++++++++++++++----- 4 files changed, 63 insertions(+), 11 deletions(-)
diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h index 92eb878..6ae3e94 100644 --- a/arch/arm/include/asm/arch-rockchip/bootrom.h +++ b/arch/arm/include/asm/arch-rockchip/bootrom.h @@ -22,6 +22,6 @@ void back_to_bootrom(void); /**
- Assembler component for the above (do not call this directly)
*/ -void _back_to_bootrom_s(void); +void _back_to_bootrom_s(int mode);
Please add documentation for externally visible functions.
Okay.
#endif diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index d9b25d5..3ab0c30 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -113,6 +113,7 @@ config ROCKCHIP_RK3399 select SPL_SERIAL_SUPPORT select SPL_DRIVERS_MISC_SUPPORT select ENABLE_ARM_SOC_BOOT0_HOOK
- select ROCKCHIP_BROM_HELPER select DEBUG_UART_BOARD_INIT help The Rockchip RK3399 is a ARM-based SoC with a dual-core Cortex-A72
@@ -149,6 +150,18 @@ config TPL_ROCKCHIP_BACK_TO_BROM SPL will return to the boot rom, which will then load the U-Boot binary to keep going on.
+config ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- hex "Bootrom download mode flag register address"
- default 0x200081c8 if ROCKCHIP_RK3036
- default 0xff730094 if ROCKCHIP_RK3288
- default 0xff738200 if ROCKCHIP_RK3368
- default 0xff320300 if ROCKCHIP_RK3399
- default 0x10300580 if ROCKCHIP_RV1108
- default 0x00
If this is not user-configurable (i.e. if it is a per-chip constant), we should define this in a header file. I would suggest to do the detection/mapping either in include/asm/arch-rockchip/bootrom.h or in a cpu-specific header that gets included from there.
Actually this is user-configuarable, we just chose a register that not be used by the system to pass the boot mode flag. And we also have boards that don't want to enable this function, so they can set the register address to 0. then we will ship the mode check .
Understood.
- help
The Soc will return to bootrom download mode if thisregister set
to BOOTROM_DOWNLOAD_FLAG.Documenting here what BOOTROM_DOWNLOAD_FLAG is or where it can be found would be very helpful to anyone coming across this in the future.
okay
config ROCKCHIP_SPL_RESERVE_IRAM hex "Size of IRAM reserved in SPL" default 0x4000 diff --git a/arch/arm/mach-rockchip/bootrom.c b/arch/arm/mach-rockchip/bootrom.c index 8380e4e..6f0d583 100644 --- a/arch/arm/mach-rockchip/bootrom.c +++ b/arch/arm/mach-rockchip/bootrom.c @@ -12,5 +12,5 @@ void back_to_bootrom(void) #if CONFIG_IS_ENABLED(LIBCOMMON_SUPPORT) puts("Returning to boot ROM...\n"); #endif
- _back_to_bootrom_s();
- _back_to_bootrom_s(0);
} diff --git a/arch/arm/mach-rockchip/save_boot_param.S b/arch/arm/mach-rockchip/save_boot_param.S index 50fce20..f1bed0b 100644 --- a/arch/arm/mach-rockchip/save_boot_param.S +++ b/arch/arm/mach-rockchip/save_boot_param.S @@ -7,11 +7,25 @@
#include <linux/linkage.h>
+#define BACK_TO_BROM_DOWNLOAD_FLAG 0xEF08A53C
This looks like it should be defined in bootrom.h
It has been move to boot-mode.h in new version.
#if defined(CONFIG_ARM64) .globl SAVE_SP_ADDR SAVE_SP_ADDR: .quad 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr x8, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr x9, [x8]
- ldr x0, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp x9, x0
- b.ne save_boot_params_ret
- mov x9, xzr
- str x9, [x8] /* clear flag */
- mov x0, #1 /* indicate the bootrom to enter
download mode */
- b _back_to_bootrom_s
How does this ever get entered? If the download flag is already set prior to this code being executed, then the BROM would certainly not even come here?
BROM would not check the boot mode register, it only enter bootrom download mode if we return a non-zere value for it or it can't find a valid image from all the storage device.
We should document this somewhere. A comment in this code might be great to let everyone know why we are checking this here.
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
We can't predict how many settings the TPL/SPL startup code changed now and future will affect the bootrom download function, So back to bootrom download mode before anything been changed is a simple way.
Ok. I’d still like to have this in C. The only requirement for this will be having a valid stack-pointer, so we should be able to do this early (before the various initialisation runs). I think board_init_f() would be a suitable place.
When I hack this function first time, I indeed wrote a c implemented code in board_init_f on kylin-rk3036, but the usb failed connect to my PC when back to bootrom, after a long time checking whit the bootrom code author, we found the interrupts related configurations are changed. Then I try to save and restore the VBAR, then the bootrom download function works. But when I tested this function on rk3288 based board, it failed again, and I found rk3288 bootrom require a different interrupt configuration with rk3036 after a long time dig, the interrupts vector base should be 0xffff0000(other arm32 based boards are 0x0000), so the V bit of SCTLR should be set to 1, but the SPL startup code set it to zero. Then I have the idea back to bootrom download mode as early as possible when the download flag is set, Because no matter how many parameters I saved and restored today, no one can make sure that other parameters will not changed by start.S in the future(maybe more properties changed about the interrupt, maybe the change of mmu /caches, ), because we always have the chance to modify the startup code by the desire of new feature or the need to workaround something for a new soc, what's more the start.S it's now have many #if / #else configuration, this still have risk to change the default configurations which will be used in bootrom download mode. If we rely on a save and restore policy, this function may work well today, but may failed some days later just because some one changed another configuration in start.S.
+ENDPROC(check_back_to_brom_dnl_flag)
ENTRY(save_boot_params) sub sp, sp, #0x60 stp x29, x30, [sp, #0x50] @@ -23,14 +37,22 @@ ENTRY(save_boot_params) ldr x8, =SAVE_SP_ADDR mov x9, sp str x9, [x8] +#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else b save_boot_params_ret /* back to my caller */ +#endif
Please avoid the #if #else #endif here. Could you simply call into a function that handles this correctly for both cases?
I have to skip the check if the REG address is zero.
Good idea. Having a check for zero would match exactly how you described the handling of the Kconfig variable. Note that you should document the special meaning of zero both in a comment and in the Kconfig help text.
However, this should fold back onto just the save_boot_params case anyway, if you can implement the checking function in C (as suggested above).
Please see my explanation above.
ENDPROC(save_boot_params)
+/*
- x0: return value for bootrom, none-zero for bootrom download
typo: non-zero
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr x0, =SAVE_SP_ADDR
- ldr x0, [x0]
- mov sp, x0
- ldr x1, =SAVE_SP_ADDR
- ldr x1, [x1]
- mov sp, x1 ldp x29, x30, [sp, #0x50] ldp x27, x28, [sp, #0x40] ldp x25, x26, [sp, #0x30]
@@ -38,7 +60,6 @@ ENTRY(_back_to_bootrom_s) ldp x21, x22, [sp, #0x10] ldp x19, x20, [sp] add sp, sp, #0x60
- mov x0, xzr ret
ENDPROC(_back_to_bootrom_s) #else @@ -46,6 +67,18 @@ ENDPROC(_back_to_bootrom_s) SAVE_SP_ADDR: .word 0
+ENTRY(check_back_to_brom_dnl_flag)
- ldr r0, =CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- ldr r1, [r0]
- ldr r2, =BACK_TO_BROM_DOWNLOAD_FLAG
- cmp r1, r2
- bne save_boot_params_ret
- mov r3, #0
- str r3, [r0] @clear flag
- mov r0, #1 @indicate the bootrom to enter download
mode
- b _back_to_bootrom_s
+ENDPROC(check_back_to_brom_dnl_flag)
See above: should be possible to do in C.
/*
- void save_boot_params
@@ -55,15 +88,21 @@ 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
+#if CONFIG_ROCKCHIP_BACK_TO_BROM_DOWNLOAD_REG
- b check_back_to_brom_dnl_flag
+#else
- b save_boot_params_ret
+#endif
See above.
ENDPROC(save_boot_params)
+/*
- r0: return value for bootrom, none-zero for bootrom download
mode and zero for normal boot mode- */
.globl _back_to_bootrom_s ENTRY(_back_to_bootrom_s)
- ldr r0, =SAVE_SP_ADDR
- ldr sp, [r0]
- mov r0, #0
- ldr r1, =SAVE_SP_ADDR
- ldr sp, [r1] pop {r1-r12, pc}
ENDPROC(_back_to_bootrom_s) #endif
On 13 Sep 2017, at 10:36, Andy Yan andy.yan@rock-chips.com wrote:
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
We can't predict how many settings the TPL/SPL startup code changed now and future will affect the bootrom download function, So back to bootrom download mode before anything been changed is a simple way.
Ok. I’d still like to have this in C. The only requirement for this will be having a valid stack-pointer, so we should be able to do this early (before the various initialisation runs). I think board_init_f() would be a suitable place.
When I hack this function first time, I indeed wrote a c implemented code in board_init_f on kylin-rk3036, but the usb failed connect to my PCwhen back to bootrom, after a long time checking whit the bootrom code author, we found the interrupts related configurations are changed. Then I try to save and restore the VBAR, then the bootrom download function works. But when I tested this function on rk3288 based board, it failed again, and I found rk3288 bootrom require a different interrupt configuration with rk3036 after a long time dig, the interrupts vector base should be 0xffff0000(other arm32 based boards are 0x0000), so the V bit of SCTLR should be set to 1, but the SPL startup code set it to zero. Then I have the idea back to bootrom download mode as early as possible when the download flag is set, Because no matter how many parameters I saved and restored today, no one can make sure that other parameters will not changed by start.S in the future(maybe more properties changed about the interrupt, maybe the change of mmu /caches, ), because we always have the chance to modify the startup code by the desire of new feature or the need to workaround something for a new soc, what's more the start.S it's now have many #if / #else configuration, this still have risk to change the default configurations which will be used in bootrom download mode. If we rely on a save and restore policy, this function may work well today, but may failed some days later just because some one changed another configuration in start.S.
When looking at what happens (on armv7) between the save_boot_params and the call to _main (which in turn just sets up SP and calls into board_init_f), there isn’t much happening: it really is only cpu_init_cp15 and cpu_init_crit that will be of concern. I really wonder whether we could have a sufficient C runtime (i.e. SP valid) available before those run.
Does your BROM always call us with the SP valid (I know that that’s the case on the RK3399 and RK3368), so that we could run on the BROM’s stack here?
Hi Philipp:
On 2017年09月13日 16:50, Dr. Philipp Tomsich wrote:
On 13 Sep 2017, at 10:36, Andy Yan andy.yan@rock-chips.com wrote:
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
We can't predict how many settings the TPL/SPL startup code changed now and futurewill affect the bootrom download function, So back to bootrom download mode before anything been changed is a simple way.
Ok. I’d still like to have this in C. The only requirement for this will be having a valid stack-pointer, so we should be able to do this early (before the various initialisation runs). I think board_init_f() would be a suitable place.
When I hack this function first time, I indeed wrote a c implemented code in board_init_f on kylin-rk3036, but the usb failed connect to my PCwhen back to bootrom, after a long time checking whit the bootrom code author, we found the interrupts related configurations are changed. Then I try to save and restore the VBAR, then the bootrom download function works. But when I tested this function on rk3288 based board, it failed again, and I found rk3288 bootrom require a different interrupt configuration with rk3036 after a long time dig, the interrupts vector base should be 0xffff0000(other arm32 based boards are 0x0000), so the V bit of SCTLR should be set to 1, but the SPL startup code set it to zero. Then I have the idea back to bootrom download mode as early as possible when the download flag is set, Because no matter how many parameters I saved and restored today, no one can make sure that other parameters will not changed by start.S in the future(maybe more properties changed about the interrupt, maybe the change of mmu /caches, ), because we always have the chance to modify the startup code by the desire of new feature or the need to workaround something for a new soc, what's more the start.S it's now have many #if / #else configuration, this still have risk to change the default configurations which will be used in bootrom download mode. If we rely on a save and restore policy, this function may work well today, but may failed some days later just because some one changed another configuration in start.S.
When looking at what happens (on armv7) between the save_boot_params and the call to _main (which in turn just sets up SP and calls into board_init_f), there isn’t much happening: it really is only cpu_init_cp15 and cpu_init_crit that will be of concern.
The bellow codes changes the V bit and VBAR address, that are what cause problems on rockchip armv7 based boards.
As for armv7, I haven't check what will cause problem.
As bootrom is a very critical environment and very hard to debug, So I hope to keep it as clean as possible when we jump back to it.
/* * Setup vector: * (OMAP4 spl TEXT_BASE is not 32 byte aligned. * Continue to use ROM code vector only in OMAP4 spl) */ #if !(defined(CONFIG_OMAP44XX) && defined(CONFIG_SPL_BUILD)) /* Set V=0 in CP15 SCTLR register - for VBAR to point to vector */ mrc p15, 0, r0, c1, c0, 0 @ Read CP15 SCTLR Register bic r0, #CR_V @ V = 0 mcr p15, 0, r0, c1, c0, 0 @ Write CP15 SCTLR Register
/* Set vector address in CP15 VBAR register */ ldr r0, =_start mcr p15, 0, r0, c12, c0, 0 @Set VBAR #endif
I really wonder whether we could have a sufficient C runtime (i.e. SP valid) available before those run.
Does your BROM always call us with the SP valid (I know that that’s the case on the RK3399 and RK3368), so that we could run on the BROM’s stack here?
On 13 Sep 2017, at 10:50, Dr. Philipp Tomsich philipp.tomsich@theobroma-systems.com wrote:
On 13 Sep 2017, at 10:36, Andy Yan andy.yan@rock-chips.com wrote:
If you just always save the boot_params and check the download flag later from C code, then you could have this implemented in C. This will remove the need to write two separate assembly functions (for AArch64 and AArch32) and generally be more readable. Please revise.
We can't predict how many settings the TPL/SPL startup code changed now and future will affect the bootrom download function, So back to bootrom download mode before anything been changed is a simple way.
Ok. I’d still like to have this in C. The only requirement for this will be having a valid stack-pointer, so we should be able to do this early (before the various initialisation runs). I think board_init_f() would be a suitable place.
When I hack this function first time, I indeed wrote a c implemented code in board_init_f on kylin-rk3036, but the usb failed connect to my PC when back to bootrom, after a long time checking whit the bootrom code author, we found the interrupts related configurations are changed. Then I try to save and restore the VBAR, then the bootrom download function works. But when I tested this function on rk3288 based board, it failed again, and I found rk3288 bootrom require a different interrupt configuration with rk3036 after a long time dig, the interrupts vector base should be 0xffff0000(other arm32 based boards are 0x0000), so the V bit of SCTLR should be set to 1, but the SPL startup code set it to zero. Then I have the idea back to bootrom download mode as early as possible when the download flag is set, Because no matter how many parameters I saved and restored today, no one can make sure that other parameters will not changed by start.S in the future(maybe more properties changed about the interrupt, maybe the change of mmu /caches, ), because we always have the chance to modify the startup code by the desire of new feature or the need to workaround something for a new soc, what's more the start.S it's now have many #if / #else configuration, this still have risk to change the default configurations which will be used in bootrom download mode. If we rely on a save and restore policy, this function may work well today, but may failed some days later just because some one changed another configuration in start.S.
When looking at what happens (on armv7) between the save_boot_params and the call to _main (which in turn just sets up SP and calls into board_init_f), there isn’t much happening: it really is only cpu_init_cp15 and cpu_init_crit that will be of concern. I really wonder whether we could have a sufficient C runtime (i.e. SP valid) available before those run.
Does your BROM always call us with the SP valid (I know that that’s the case on the RK3399 and RK3368), so that we could run on the BROM’s stack here?
Just to explain my thinking here… If we had a valid SP, we could mark our devices via Kconfig accordingly by introducing a new config (e.g. $(SPL_TPL_)BROM_PERFORMS_C_CALL for this) and then do something along these lines:
in start.S: #if CONFIG_IS_ENABLED(BROM_PERFORMS_C_CALL) b brom_handoff_f .globl brom_handoff_f_ret brom_handoff_f_ret: #endif
and have a C file implementing the following (if setjmp/longjmp is not yet implemented for AArch32 and AArch64, this will be a quick exercise):
/* The following is functionally identical to mach-rockchip/save_boot_param.S */ jmp_buf* brom_ctx = NULL;
enum { BROM_SETJMP_CONTINUE = 0 BROM_RETURN_NORMAL = 1, BROM_RETURN_DNL = 2, }
int brom_handoff_t(void) { jmp_buf saved_brom_ctx; int res ;
res = setjmp(saved_brom_ctx); switch (res) { case BROM_SETJMP_CONTINUE: brom_ctx = &saved_brom_ctx; res = brom_handoff_f_ret(); /* needs a better name */ break;
case BROM_RETURN_NORMAL: res = 0; break;
case BROM_RETURN_DNL: res = MAGIC_VALUE_TO_PASS_BACK; break; }
return res; }
void back_to_bootrom(void) { longjmp(*brom_ctx, BROM_RETURN_NORMAL); }
participants (4)
-
Andy Yan -
Dr. Philipp Tomsich -
Kever Yang -
Philipp Tomsich