johang/sd-card-images

Empty /boot partition, kernel and u-boot files in rootfs

chschnell opened this issue · 2 comments

chschnell commented

First off, thanks a lot for this impressive work.

I tried to build an image for Banana Pi BPI-M2-BERRY with Bullseye using:

sudo docker run --rm -v /tmp/sd-images:/artifacts sd-images build-boot \
    banana_pi_m2_berry allwinner-v40 bananapi_m2_berry_defconfig arm-linux-gnueabihf

sudo docker run --rm -v /tmp/sd-images:/artifacts sd-images build-debian \
    debian armhf bullseye

Two binary files were created, as expected, I concatenated them using:

zcat /tmp/sd-images/boot-banana_pi_m2_berry.bin.gz \
     /tmp/sd-images/debian-bullseye-armhf-XXXXXX.bin.gz > sd-card.img

After flashing sd-card.img to my SD card the device didn't boot. When inspecting the file systems of both .bin files I noticed that:

  1. /boot partition in boot-...bin.gz is empty
  2. /boot directory in debian-...bin.gz contains kernel and u-boot files
  3. trying to move the files from debian-...bin.gz to boot-...bin.gz failed due to a lack of space in the 32M /boot partition

I then tried the same for a Raspberry Pi Zero 2 W and the final image turned out to be structurally ok (I didn't boot it though): two partitions (vfat and ext4), boot files in vfat boot partition and /boot mount point in ext4 rootfs empty.

Finally I ran another attempt for a Banana Pi BPI-M2-ZERO, but it failed for the same problem my initial attempt (Banana Pi BPI-M2-BERRY) failed, vfat /boot partition is empty.

I also checked your downloadable binaries for the two Banana Pis, same problem (mount them and check yourself).

johang commented

Allwinner images have empty FAT partition by design. The bootloader is written to a space between partition table and the FAT partition. The bootloader then loads boot.scr from /boot in the ext4 partition, which then loads dtb and kernel from the ext4 partition.

Connect to the UART and show what is outputs during boot.

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chschnell commented

Thanks for the quick clarification, I knew about the bootloader but it's the first time I come across this file layout.

This time it booted perfectly fine, I was simply too impatient earlier (my monitor didn't get a signal for some time). Found that out after connecting the serial port.

I very much apologize for my blunder, and again thanks a lot for your effort here, love it!

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