[Bug 1925267] Re: u-boot unmatched dtb does not match kernel dtb

[William Wilson]

** Description changed:

+ [Impact]
+ 
+  * Without the fix, Unmatched images will not boot in qemu
+ 
+ [Test Case]
+ 
+  * `qemu-system-riscv64 \
+         -machine virt -nographic -m 2048 -smp 4 \
+         -bios /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_jump.elf \
+         -kernel /usr/lib/u-boot/qemu-riscv64_smode/uboot.elf \
+         -device virtio-net-device,netdev=eth0 -netdev user,id=eth0 \
+         -drive file=<unmatched image file>,format=raw,if=virtio`
+  * Observe that the above command fails to boot the image in qemu
+  * Build a new unmatched image with the version of u-boot-menu
+    and u-boot in -proposed. Both are needed.
+  * Re-run the above qemu command on the new image, and observe
+    that it boots
+  * Also boot the new image on HiFive Unmatched hardware to ensure it
+    boots.
+ 
+ [Regression Potential]
+   While multiple hardware platforms use u-boot, the only Ubuntu
+   image using u-boot-menu is the Unmatched. The risk of regression
+   is therefore very low, and only the hardware boot and qemu boot
+   need to be tested. 
+ 
+ [Original Description]
  u-boot unmatched dtb does not match kernel dtb
  
  We have reverted u-boot-menu upload and stopped using kernel provided
  dtbs, because that was preventing booting hirsute images under qemu. As
  dtb generated by qemu should be used, and there is no kernel provided
  dtb for qemu platform.
  
  This resulted in unamtched board using dtb provided by u-boot, instead
  of loading and using dtb provided by the kernel builds.
  
  There are differences between u-boot & kernel dtbs that potentially
  break compat.
  
  There are two ways of fixing this:
  
  1) bring uboot dtb in-line with the kernel dtb
  
  2) fix qemu uboot to not load dtbs from disk, even when extlinux.conf
  asks to; and resume loading the matching kernel dtb from disk
  
  Option 1) sounds easier for release.
  
  The diff between u-boot's unmatched dtb & kernel provided dtb is at
  https://paste.ubuntu.com/p/YGKCvVM6yz/

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https://bugs.launchpad.net/bugs/1925267

Title:
  u-boot unmatched dtb does not match kernel dtb

Status in u-boot package in Ubuntu:
  Fix Released
Status in u-boot source package in Focal:
  New

Bug description:
  [Impact]

   * Without the fix, Unmatched images will not boot in qemu

  [Test Case]

   * `qemu-system-riscv64 \
          -machine virt -nographic -m 2048 -smp 4 \
          -bios /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_jump.elf \
          -kernel /usr/lib/u-boot/qemu-riscv64_smode/uboot.elf \
          -device virtio-net-device,netdev=eth0 -netdev user,id=eth0 \
          -drive file=<unmatched image file>,format=raw,if=virtio`
   * Observe that the above command fails to boot the image in qemu
   * Build a new unmatched image with the version of u-boot-menu
     and u-boot in -proposed. Both are needed.
   * Re-run the above qemu command on the new image, and observe
     that it boots
   * Also boot the new image on HiFive Unmatched hardware to ensure it
     boots.

  [Regression Potential]
    While multiple hardware platforms use u-boot, the only Ubuntu
    image using u-boot-menu is the Unmatched. The risk of regression
    is therefore very low, and only the hardware boot and qemu boot
    need to be tested. 

  [Original Description]
  u-boot unmatched dtb does not match kernel dtb

  We have reverted u-boot-menu upload and stopped using kernel provided
  dtbs, because that was preventing booting hirsute images under qemu.
  As dtb generated by qemu should be used, and there is no kernel
  provided dtb for qemu platform.

  This resulted in unamtched board using dtb provided by u-boot, instead
  of loading and using dtb provided by the kernel builds.

  There are differences between u-boot & kernel dtbs that potentially
  break compat.

  There are two ways of fixing this:

  1) bring uboot dtb in-line with the kernel dtb

  2) fix qemu uboot to not load dtbs from disk, even when extlinux.conf
  asks to; and resume loading the matching kernel dtb from disk

  Option 1) sounds easier for release.

  The diff between u-boot's unmatched dtb & kernel provided dtb is at
  https://paste.ubuntu.com/p/YGKCvVM6yz/

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