Can't boot from sd-card on BeagleBone Black

[Peter Robinson]

On Sun, Aug 30, 2020 at 6:41 PM Pavel Yermolenko <py.missuri at sunrise.ch> wrote:
>
> Hello,
>
> I've tried two different default configurations while building u-boot:
>
>   * am335x_boneblack_vboot_defconfig
>   * am335x_evm_defconfig
>
> I formatted sd-card with this script:
> https://github.com/PacktPublishing/Mastering-Embedded-Linux-Programming-Second-Edition/blob/master/format-sdcard.sh
> Then I copied *MLO* and *u-boot.img* into the boot partition.
> Here is boot log for am335x_boneblack_vboot_defconfig case (for
> am335x_evm_defconfig it's similar):
>
>     |U-Boot SPL 2020.10-rc3 (Aug 28 2020 - 10:16:38 +0200)|
>     |WDT: Not found!
>     Trying to boot from MMC1
>     Loading Environment from FAT... *** Warning - bad CRC, using default
>     environment
>     Loading Environment from MMC... *** Warning - bad CRC, using default
>     environment
>       U-Boot 2020.10-rc3 (Aug 28 2020 - 10:16:38 +0200)
>       CPU : AM335X-GP rev 2.1
>     Model: TI AM335x BeagleBone Black
>     DRAM: 512 MiB
>     MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1
>     Loading Environment from FAT... *** Warning - bad CRC, using default
>     environment
>     Loading Environment from MMC... *** Warning - bad CRC, using default
>     environment
>       <ethaddr> not set. Validating first E-fuse MAC
>     Net: eth2: ethernet at 4a100000, eth3: usb_ether
>     Press SPACE to abort autoboot in 2 seconds
>     switch to partitions #0, OK
>     mmc0 is current device
>     SD/MMC found on device 0
>     Failed to load 'boot.scr'
>     Failed to load 'uEnv.txt'
>     switch to partitions #0, OK
>     mmc0 is current device
>     Scanning mmc 0:1...
>     switch to partitions #0, OK
>     mmc0 is current device
>     SD/MMC found on device 0
>     Failed to load '/boot/zImage'
>     switch to partitions #0, OK
>     mmc1(part 0) is current device
>     Scanning mmc 1:1...
>     Found /boot/extlinux/extlinux.conf|
>
> As you see, it tries to boot from MMC1 (I suppose that it's sd-card), it
> fails to boot from MMC1, then it switches to eMMC (where is full Linux,
> i.e. boot + kernel) and boots successfully from eMMC.
>
> There are warnings: "bad CRC". Probably this is the cause of boot failure ?

No, that's just because it can't find a saved environment variables to load.

> Could it be problem of copying of u-boot files ... or erroneous
> formatting of sd-card.
> Have someone an idea how to check these issues.

It looks off a mSD card OK for me, have you tried holding down the
button (the one near the mSD card) when powering on to tell it to
force the mSD card?