Hi Jonas,

On 2024/2/5 20:34, Jonas Karlman wrote:
Hi Quentin,

On 2024-02-05 11:49, Quentin Schulz wrote:
Hi Jonas,

On 2/2/24 01:12, Jonas Karlman wrote:
Add support to reset to bootrom download mode on hang in U-Boot SPL and
proper. ROCKCHIP_HANG_TO_BROM can be used to enable this feature.

Example when SPL cannot load FIT:

    U-Boot SPL 2024.04-rc1 (Feb 01 2024 - 23:01:12 +0000)
    Trying to boot from MMC1
    mmc_load_image_raw_sector: mmc block read error
    Trying to boot from MMC2
    Card did not respond to voltage select! : -110
    spl: mmc init failed with error: -95
    Trying to boot from MMC1
    mmc_load_image_raw_sector: mmc block read error
    SPL: failed to boot from all boot devices
    ### ERROR ### Please RESET the board ###
    entering download mode ...
    resetting ...

Procedure to start bootrom download mode:
- U-Boot SPL or proper write 0xEF08A53C to BOOT_MODE_REG and then reset
- Bootrom loads and run boot code (TPL) from e.g. SPI > eMMC > SD-card
- TPL check for 0xEF08A53C in BOOT_MODE_REG very early, i.e. Rockchip
    TPL blobs check for this value directly at start
- TPL return to bootrom with a return value != 0
- Bootrom enter download mode

This also fixes an issue where the BOOT_MODE_REG is reset to 0 when
board is reset on RK35xx after TF-A has been loaded. To fix this the
SOC_CON1 reg value is reset prior to issuing a global reset.

The RK356x TF-A blobs will clear SOC_CON1 as part of a PSCI reset,
however the RK3588 TF-A blobs does not seem to clear SOC_CON1.

Signed-off-by: Jonas Karlman <jo...@kwiboo.se>
I'm wondering if there isn't a simpler way to do this?

board_boot_order() could parse u-boot,spl-boot-order for e.g. "bootrom",
the same way it does for "same-as-spl" for example.

If it is set, then add BOOT_DEVICE_BOOTROM to spl_boot_list.

Then this would call spl_return_to_bootrom() from
common/spl/spl_bootrom.c which in turns would call
board_return_to_bootrom() and back_to_bootrom().

What do you think?
Something like that is what I did in my initial implementation :-)

I appended a BOOT_DEVICE_BOOTROM at the end of board_boot_order() and
implemented necessary parts in spl_return_to_bootrom(), and that worked
great for SPL.

However, to catch a hang() in U-Boot proper, e.g. a failed initcall, the
only existing integration callback for hang() is to override
show_boot_progress().

Because the use of show_boot_progress() worked for both SPL and U-Boot
proper (probably also TPL) it seemed better to only have one integration
part for all phases.

I am still not sure exactly when we would want to fall back into bootrom
download mode. Always at a hang() or at controlled parts e.g. when no
FIT can be loaded.
There are two case need to consider when hang() happen:
- For release version: a reboot and get into reset into bootrom download mode if boot fail more than 3 times; - For debug version: a dump stack with hang() will be better(which is used in rockchip vendor u-boot); Reboot to bootrom download when hang() happen is handy for U-Boot error happen, no need to press the reset
and recovery/download key in this case.
The final logic would be: fall back to usb boot(bootrom) whenever we fail to boot in to next stage,
so that we have chance to update an available firmware.

Thanks,
- Kever

I am open for any suggestions.

Regards,
Jonas

Cheers,
Quentin

Reply via email to