Banana Pi M2U No boot

    After this I've tried the older LibreELEC-R40.arm-12.0.2-bananapi-m2u.img.gz image and it proceeds further, shows Libreelec picture

    After that I've had other problems but that's probably unrelated to issue above

    I had 12.0.2 running on a BananaPi-M2 Berry and tried the update procedure from within LibreElec console. Screen went black and further no boot.
    So I flashed the 12.2.0 and that does not boot. So tried the 12.0.2-bananapi-m2u image and that does not boot either.
    So I tried 2020-04-19-raspbian-jessie-bpi-m2u-sd-emmc.img and that does boot.

    Any ideas?

    If neither LE or Armbian images for the board boot, it's either bad hardware or something in common boot code that both distros share. Do you have a UART cable that can be attached to show early boot output?

    Tried other serial adapter. Now get the message:

    U-Boot SPL 2025.07 (Oct 12 2025 - 20:27:55 +0000)
    DRAM 1024 Mib
    Trying to boot from MMC1

    And that's the end.

    When I start from the raspbian-jessie I get a different startup.
    First:
    [294]HELLO BPI! BOOT0 is starting!
    it ends with:
    [600]Jump to secend boot
    then
    U-Boot 2014.07 (April 19 2020 - 14:29:12) Allwinner Technology
    and then continues

    Edited once, last by warnerk: Merged a post created by warnerk into this post. (October 13, 2025 at 1:33 PM).

    If I can help, please say so.
    The strange thing is that I had 12.0.2 running on the BPi and then I decided to update...
    I shouldn't have done that.. But talking afterwards is always easy..
    And I tried to install 12.0.2 and that does not start either..
    puzzled...

    I tried 10.0.4 and that boots and starts.

    I'll try 11.0.6 next

    Edited 2 times, last by warnerk: Merged a post created by warnerk into this post. (October 13, 2025 at 8:40 PM).

    I tried 11.0.6 and that works.
    I tried 12.0.2 and that works too.

    I was misinterpreting that the green led should show activity when the system starts, but that is not the case.
    At least not with LibreElec. With Raspbian it does.

    I found the issue, but I'm not sure how to solve it yet. It's extremely weird. U-Boot is not built correctly, that much is obvious. However, reason why is curious. If I put .git folder into source folder, then it builds correctly. It seems that some tool require git metadata to decide something. I have to find which tool causes that.

    This is second weird build bug that I'm researching in last week or so...

    I hit the same hang with LibreELEC 12.2.1 on a Banana Pi M2 Ultra (R40) and tracked it down with the serial console and FEL. Serial output, then nothing:

    Code
    U-Boot SPL 2025.07 (Nov 01 2025 - 06:09:49 +0000)
DRAM: 2048 MiB
Trying to boot from MMC1

    The same image boots fine with the U-Boot 2024.01 from 12.0.2.

    Cause: U-Boot 2025.07 contains commit 358d1cc232c3 ("spl: Align FDT load address"), so the SPL now puts the device tree at the end of U-Boot proper rounded up to 8 bytes. U-Boot proper (OF_SEPARATE) still looks for it exactly at _end, which 2025.07 doesn't align. In the 12.2.1 build for this board U-Boot is 367164 bytes (4 more than a multiple of 8), so U-Boot proper finds no device tree and hangs before its serial console starts. That's why nothing at all is printed after the SPL. 2024.01 isn't affected (its U-Boot is 359920 bytes and its SPL doesn't round). Whether a board is hit depends on its U-Boot size, so other 32-bit Allwinner boards may or may not be affected.

    Verified over FEL: LibreELEC's own 12.2.1 U-Boot boots when the device tree is placed exactly at _end, and hangs with no output when it's placed 4 bytes higher (where the 2025.07 SPL puts it).

    Fix: upstream fixed it in commit 8b0ebe054bb3 ("arm: Update linker scripts to ensure appended device tree is aligned", in U-Boot v2026.04 and later). LibreELEC master already uses U-Boot 2026.10, which works on my board. For 12.2 the backport is two lines in the linker scripts (. = ALIGN(8); before _end). With it, a real SD boot of 12.2.1 works. I've opened a GitHub issue with the patch: https://github.com/LibreELEC/LibreELEC.tv/issues/11966

    Workaround until then: write the 12.2.1 image to the SD card, then replace its bootloader with the one from the 12.0.2 image (both have the first partition at 4 MiB, the bootloader area is 8 KiB to 4 MiB). On Linux, with the card as /dev/sdX (check with lsblk!):

    Code
    gunzip -c LibreELEC-R40.arm-12.0.2-bananapi-m2u.img.gz | dd of=uboot-12.0.2.bin bs=1k skip=8 count=4088
sudo dd if=uboot-12.0.2.bin of=/dev/sdX bs=1k seek=8 conv=fsync

    That's what my board runs now (12.2.1, from eMMC, with U-Boot 2024.01).

    Thanks for the information. I noticed this issue but was unable to find the cause for it after spending quite some time on it.

    In any case, 12.x version won't have any future update, so any M2U user will have to wait on LE13 or use this workaround.