Re: [U-Boot] [PATCH v4 10/18] rockchip: boot0 hook: support early return for RK3188/RK3066-style BROM

On 10 Oct 2017, at 11:22, Andy Yan andy.yan@rock-chips.com wrote:

Hi:

On 2017年10月10日 17:01, Andy Yan wrote:

...

Hi Philipp:

On 2017年10月07日 03:28, Philipp Tomsich wrote:

...

Some Rockchip BROM versions (e.g. the RK3188 and RK3066) first read 1KB data from NAND into SRAM and executes it. Then, following a return to bootrom, the BROM loads additional code to SRAM (not overwriting the first block read) and reenters at the same address as the first time.

To support booting either a TPL (on the RK3066) or SPL (on the RK3188) using this model of having to count entries, this commit adds code to the boot0 hook to track the number of entries and handle them accordingly.

Signed-off-by: Philipp Tomsich philipp.tomsich@theobroma-systems.com Signed-off-by: Paweł Jarosz paweljarosz3691@gmail.com

---

Changes in v4: None Changes in v3: None Changes in v2: None

arch/arm/include/asm/arch-rockchip/boot0.h | 24 ++++++++++++++++++------ arch/arm/mach-rockchip/Kconfig | 28 ++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/arch-rockchip/boot0.h b/arch/arm/include/asm/arch-rockchip/boot0.h index f7c6146..06091d0 100644 --- a/arch/arm/include/asm/arch-rockchip/boot0.h +++ b/arch/arm/include/asm/arch-rockchip/boot0.h @@ -19,12 +19,24 @@ * beginning of the executable. However, as we want to keep * this generic and make it applicable to builds that are like * the RK3368 (TPL needs this, SPL doesn't) or the RK3399 (no

• * TPL, but extra space needed in the SPL), we simply repeat
  

• * the 'b reset' with the expectation that the first one will
  

• * be overwritten, if this is the first stage contained in the
  

• * final image created with mkimage)...
  

• * TPL, but extra space needed in the SPL), we simply insert
  

• * a branch-to-next-instruction-word with the expectation that
  

• * the first one may be overwritten, if this is the first stage
  

• * contained in the final image created with mkimage)...
   */
  

• b reset /* may be overwritten --- should be 'nop' or a 'b reset' */

• b 1f /* if overwritten, entry-address is at the next word */

+1: +#endif +#if CONFIG_IS_ENABLED(ROCKCHIP_EARLYRETURN_TO_BROM)

• adr r3, entry_counter
• ldr r0, [r3]
• cmp r0, #1 /* check if entry_counter == 1 */
• beq reset /* regular bootup */
• add r0, #1
• str r0, [r3] /* increment the entry_counter in memory */

It seems that we need to clear r0 to zero before return to bootrom, a non-zero return value will drive the system to bootrom download mode.

Did you test if clearing the r0-register before returning fixes this and we boot through into SPL? If so, I’ll create a v5 of the patch … if not, we will need to dig deeper to determine why this does not work as expected.

...

...

• bx lr /* return to bootrom */

This seems not work on rk3188, When I track the code flow with DS-5, I

found the entry_counter always be zero when we run here from bootrom(even it is set to 1 before return to bootrom), so it return to bootrom again and again.

...

+entry_counter:

• .word 0 #endif b reset #if !defined(CONFIG_ARM64)

@@ -32,7 +44,7 @@ * For armv7, the addr '_start' will used as vector start address * and write to VBAR register, which needs to aligned to 0x20. */

• .align(5)

• .align(5), 0x0 _start: ARM_VECTORS #endif

diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig index 31e9864..d59a1d5 100644 --- a/arch/arm/mach-rockchip/Kconfig +++ b/arch/arm/mach-rockchip/Kconfig @@ -158,6 +158,34 @@ config ROCKCHIP_SPL_RESERVE_IRAM config ROCKCHIP_BROM_HELPER bool +config SPL_ROCKCHIP_EARLYRETURN_TO_BROM

•    bool "SPL requires early-return (for RK3188-style BROM) to BROM"
  

• depends on SPL && ENABLE_ARM_SOC_BOOT0_HOOK
• help

•  Some Rockchip BROM variants (e.g. on the RK3188) load the
  

•  first stage in segments and enter multiple times. E.g. on
  

•  the RK3188, the first 1KB of the first stage are loaded
  

•  first and entered; after returning to the BROM, the
  

•  remainder of the first stage is loaded, but the BROM
  

•  re-enters at the same address/to the same code as previously.
  

•  This enables support code in the BOOT0 hook for the SPL stage
  

•  to allow multiple entries.
  

+config TPL_ROCKCHIP_EARLYRETURN_TO_BROM

•    bool "TPL requires early-return (for RK3188-style BROM) to BROM"
  

• depends on TPL && ENABLE_ARM_SOC_BOOT0_HOOK
• help

•  Some Rockchip BROM variants (e.g. on the RK3188) load the
  

•  first stage in segments and enter multiple times. E.g. on
  

•  the RK3188, the first 1KB of the first stage are loaded
  

•  first and entered; after returning to the BROM, the
  

•  remainder of the first stage is loaded, but the BROM
  

•  re-enters at the same address/to the same code as previously.
  

•  This enables support code in the BOOT0 hook for the TPL stage
  

•  to allow multiple entries.
  

• config SPL_MMC_SUPPORT default y if !SPL_ROCKCHIP_BACK_TO_BROM