U-Boot v2023.01 broken on riscv64 qemu virt platform: "fdt fixup event failed"

Thu Jan 12 00:40:05 CET 2023

On 1/12/23 00:29, Simon Glass wrote:
> () Hi Heinrich,
>
> On Wed, 11 Jan 2023 at 16:22, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>>
>> On 1/11/23 20:08, Karsten Merker wrote:
>>> Hello,
>>>
>>> it looks like U-Boot v2023.01 is currently broken for the riscv64
>>> architecture on the qemu "virt" platform; the boot process of a
>>> riscv64 VM fails during FDT fixup:
>>>
>>> -----8<----------8<----------8<----------8<----------8<----------8<-----
>>>
>>> OpenSBI v1.1
>>>      ____                    _____ ____ _____
>>>     / __ \                  / ____|  _ \_   _|
>>>    | |  | |_ __   ___ _ __ | (___ | |_) || |
>>>    | |  | | '_ \ / _ \ '_ \ \___ \|  _ < | |
>>>    | |__| | |_) |  __/ | | |____) | |_) || |_
>>>     \____/| .__/ \___|_| |_|_____/|____/_____|
>>>           | |
>>>           |_|
>>>
>>> Platform Name             : riscv-virtio,qemu
>>> Platform Features         : medeleg
>>> Platform HART Count       : 4
>>> Platform IPI Device       : aclint-mswi
>>> Platform Timer Device     : aclint-mtimer @ 10000000Hz
>>> Platform Console Device   : uart8250
>>> Platform HSM Device       : ---
>>> Platform Reboot Device    : sifive_test
>>> Platform Shutdown Device  : sifive_test
>>> Firmware Base             : 0x80000000
>>> Firmware Size             : 312 KB
>>> Runtime SBI Version       : 1.0
>>>
>>> Domain0 Name              : root
>>> Domain0 Boot HART         : 2
>>> Domain0 HARTs             : 0*,1*,2*,3*
>>> Domain0 Region00          : 0x0000000002000000-0x000000000200ffff (I)
>>> Domain0 Region01          : 0x0000000080000000-0x000000008007ffff ()
>>> Domain0 Region02          : 0x0000000000000000-0xffffffffffffffff (R,W,X)
>>> Domain0 Next Address      : 0x0000000080200000
>>> Domain0 Next Arg1         : 0x0000000082200000
>>> Domain0 Next Mode         : S-mode
>>> Domain0 SysReset          : yes
>>>
>>> Boot HART ID              : 2
>>> Boot HART Domain          : root
>>> Boot HART Priv Version    : v1.12
>>> Boot HART Base ISA        : rv64imafdch
>>> Boot HART ISA Extensions  : time,sstc
>>> Boot HART PMP Count       : 16
>>> Boot HART PMP Granularity : 4
>>> Boot HART PMP Address Bits: 54
>>> Boot HART MHPM Count      : 16
>>> Boot HART MIDELEG         : 0x0000000000001666
>>> Boot HART MEDELEG         : 0x0000000000f0b509
>>>
>>>
>>> U-Boot 2023.01+dfsg-1 (Jan 10 2023 - 03:18:09 +0000)
>>>
>>> CPU:   rv64imafdch_zicsr_zifencei_zihintpause_zba_zbb_zbc_zbs_sstc
>>> Model: riscv-virtio,qemu
>>> DRAM:  8 GiB
>>> Core:  31 devices, 15 uclasses, devicetree: board
>>> Flash: 32 MiB
>>> Loading Environment from nowhere... OK
>>> In:    serial at 10000000
>>> Out:   serial at 10000000
>>> Err:   serial at 10000000
>>> Net:   eth0: virtio-net#2
>>> Working FDT set to ff7344b0
>>> Hit any key to stop autoboot:  0
>>>
>>> Device 0: QEMU VirtIO Block Device
>>>               Type: Hard Disk
>>>               Capacity: 102400.0 MB = 100.0 GB (209715200 x 512)
>>> ... is now current device
>>> Scanning virtio 0:1...
>>> Found /boot/extlinux/extlinux.conf
>>> Retrieving file: /boot/extlinux/extlinux.conf
>>> U-Boot menu
>>> 1:    Debian GNU/Linux bookworm/sid 6.1.0-1-riscv64
>>> 2:    Debian GNU/Linux bookworm/sid 6.1.0-1-riscv64 (rescue target)
>>> 3:    Debian GNU/Linux bookworm/sid 6.0.0-6-riscv64
>>> 4:    Debian GNU/Linux bookworm/sid 6.0.0-6-riscv64 (rescue target)
>>> 5:    Debian GNU/Linux bookworm/sid 6.0.0-5-riscv64
>>> 6:    Debian GNU/Linux bookworm/sid 6.0.0-5-riscv64 (rescue target)
>>> Enter choice: 1:      Debian GNU/Linux bookworm/sid 6.1.0-1-riscv64
>>> Retrieving file: /boot/initrd.img-6.1.0-1-riscv64
>>> Retrieving file: /boot/vmlinux-6.1.0-1-riscv64
>>> append: root=/dev/vda1 rw noquiet
>>> Moving Image from 0x84000000 to 0x80200000, end=815e5000
>>> ## Flattened Device Tree blob at ff7344b0
>>>      Booting using the fdt blob at 0xff7344b0
>>> Working FDT set to ff7344b0
>>>      Using Device Tree in place at 00000000ff7344b0, end 00000000ff738dea
>>> Working FDT set to ff7344b0
>>> ERROR: fdt fixup event failed: -22
>>>    - must RESET the board to recover.
>>>
>>> FDT creation failed! hanging...### ERROR ### Please RESET the board ###
>>>
>>> -----8<----------8<----------8<----------8<----------8<----------8<-----
>>>
>>> Software versions used:
>>> - OpenSBI 1.1 (Debian package: opensbi 1.1-2)
>>> - QEMU 7.2.0 (Debian package: qemu-system-misc 1:7.2+dfsg-1+b2)
>>> - U-Boot v2023.01 (Debian package: u-boot-qemu 2023.01+dfsg-1)
>>>
>>> The issue is independent from the kernel that gets booted.  With
>>> U-Boot v2022.10 everything works without problems.  I have used
>>> git bisect (with qemu-riscv64_smode_defconfig) to narrow down the
>>> specific change that triggers the issue and that has resulted in
>>> the following commit:
>>>
>>> -----8<----------8<----------8<----------8<----------8<----------8<-----
>>>
>>> commit a56f663f07073713042bb0fd08053aeb667e717b (HEAD)
>>> Author: Simon Glass <sjg at chromium.org>
>>> Date:   Thu Oct 20 18:23:14 2022 -0600
>>>
>>>       vbe: Add info about the VBE device to the fwupd node
>>>
>>>       At present we put the driver in the /chosen node in U-Boot. This is a bit
>>>       strange, since U-Boot doesn't normally use that node itself. It is better
>>>       to put it under the bootstd node.
>>>
>>>       To make this work we need to copy create the node under /chosen when
>>>       fixing up the device tree. Copy over all the properties so that fwupd
>>>       knows what to do.
>>>
>>>       Update the sandbox device tree accordingly.
>>>
>>>       Signed-off-by: Simon Glass <sjg at chromium.org>
>>>
>>> -----8<----------8<----------8<----------8<----------8<----------8<-----
>>>
>>> If you should happen to run Debian/unstable, the easiest way to
>>> reproduce the problem is as follows:
>>>
>>> $ sudo apt install qemu-system-misc opensbi u-boot-qemu
>>>
>>> You can then either manually set up a riscv64 VM image as described at
>>> https://wiki.debian.org/RISC-V#Setting_up_a_riscv64_virtual_machine
>>> or you can use a prebuilt VM image from the Debian Quick Image
>>> Baker as described at https://people.debian.org/~gio/dqib/:
>>>
>>> $ wget -O riscv64-virt.zip https://gitlab.com/api/v4/projects/giomasce%2Fdqib/jobs/artifacts/master/download?job=convert_riscv64-virt
>>> $ unzip -x riscv64-virt.zip
>>> $ cd artifacts
>>>
>>> and boot the VM image with
>>>
>>> $ qemu-system-riscv64 -smp 4 -nographic -machine virt -m 8G -bios /usr/lib/riscv64-linux-gnu/opensbi/generic/fw_jump.elf -kernel /usr/lib/u-boot/qemu-riscv64_smode/u-boot.bin -object rng-random,filename=/dev/urandom,id=rng0 -device virtio-rng-device,rng=rng0 -append "console=ttyS0 rw root=/dev/vda1 scsi_mod.use_blk_mq=0" -device virtio-blk-device,drive=hd0 -drive file=image.qcow2,format=qcow2,id=hd0 -device virtio-net-device,netdev=usernet -netdev user,id=usernet,hostfwd=tcp::22222-:22
>>>
>>> Regards,
>>> Karsten
>>
>> Thanks Karsten for reporting the issue.
>>
>> Bisection points to Simon's patch:
>>
>> a56f663f0707371
>> vbe: Add info about the VBE device to the fwupd node
>>
>> In bootmeth_vbe_simple_ft_fixup() probing device vbe_simple fails
>> because all fwupd related properties are missing in the QEMU device-tree.
>>
>> The following change is enough to make QEMU boot again:
>>
>> CONFIG_BOOTMETH_VBE=n
>>
>> @Simon:
>>
>> CONFIG_BOOTMETH_VBE should default to 'no' as only the sandbox provides
>> the required data in the devicetree. Or bootmeth_vbe_simple_ft_fixup()
>> should ignore a failure to probe vbe_simple.
>
> It is supposed to ignore that failure. Could it be that there is a bug
> in vbe_find_next_device() that it should set *devp to NULL when it
> doesn't find anything?

The vbe_simple device exists on qemu-riscv64_smode_defconfig but cannot
be probed.

>
> How come this failure does not show in CI?

We currently lack tests to actually start a binary via the Linux legacy
entry point.

Best regards

Heinrich