[v3,1/3] u-boot: disable CONFIG_BLOBLIST on genericarm64 and qemuarm64

Booting u-boot on qemu with kvm is currently hanging on aarch64
build host. Root cause is in u-boot and CONFIG_BLOBLIST can be
disabled as a workaround.

To reproduce, build on kvm enabled host where "kvm-ok"
succeeds. For example genericarm64 machine and core-image-base
should then boot with:

$ runqemu slirp nographic novga snapshot kvm

On qemuarm64, default kvm setup will boot directly to kernel
and is not affected by this. If build enables u-boot as bios
then the same issue happens.

Without this config workaround, the boot hangs without
any messages in qemu output but ctrl-a-c to qemu console
can shutdown the emulated machine.

This seems to have regressed after u-boot 2025.04 update.
KVM boot can be detected from speed, for example genericarm64
boots in 550 ms with KVM and without in over 5 seconds.

Fixes: [YOCTO #15872]

Upstream u-boot discussion:
https://lists.denx.de/pipermail/u-boot/2025-May/590101.html

Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>
---
 meta/recipes-bsp/u-boot/files/disable-CONFIG_BLOBLIST.cfg | 1 +
 meta/recipes-bsp/u-boot/u-boot-common.inc                 | 4 ++++
 2 files changed, 5 insertions(+)
 create mode 100644 meta/recipes-bsp/u-boot/files/disable-CONFIG_BLOBLIST.cfg

v3: added u-boot discussion link to commit message

v2: applying to genericarm64 and qemuarm64 machines only
    https://lists.openembedded.org/g/openembedded-core/message/217054

v1: https://lists.openembedded.org/g/openembedded-core/message/217030

Hi,

On Thu, May 22, 2025 at 04:41:16PM +0300, Mikko Rapeli via lists.openembedded.org wrote:
> Add a test case to boot target system via u-boot
> using qemu with KVM. This was broken recently
> and workaround proposed to u-boot. Test case
> works with genericarm64 and qemuarm64 target machines
> compiled and tested on aarch64 build host with KVM
> support.
> 
> Test execution time with full sstate cache is
> around 170 seconds. qemu boot itself takes just
> a few seconds to full userspace.
> 
> Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>
> ---
>  meta/lib/oeqa/selftest/cases/uboot.py | 55 ++++++++++++++++++++++++++-
>  1 file changed, 53 insertions(+), 2 deletions(-)
> 
> diff --git a/meta/lib/oeqa/selftest/cases/uboot.py b/meta/lib/oeqa/selftest/cases/uboot.py
> index 39e48f8bdb..982822b389 100644
> --- a/meta/lib/oeqa/selftest/cases/uboot.py
> +++ b/meta/lib/oeqa/selftest/cases/uboot.py
> @@ -6,8 +6,8 @@
>  #
>  
>  from oeqa.selftest.case import OESelftestTestCase
> -from oeqa.utils.commands import bitbake, runqemu, get_bb_var
> -from oeqa.core.decorator.data import skipIfNotArch
> +from oeqa.utils.commands import bitbake, runqemu, get_bb_var, runCmd
> +from oeqa.core.decorator.data import skipIfNotArch, skipIfNotMachine
>  from oeqa.core.decorator import OETestTag
>  
>  uboot_boot_patterns = {
> @@ -42,3 +42,54 @@ QEMU_USE_KVM = "False"
>              status, output = qemu.run_serial(cmd)
>              self.assertEqual(status, 1, msg=output)
>              self.assertTrue("U-Boot" in output, msg=output)
> +
> +    @skipIfNotArch(['aarch64'])
> +    # Also works on genericarm64 but no way to encode that currently
> +    @skipIfNotMachine('qemuarm64', 'KVM depends that host and target architectures match, e.g. aarch64 and qemuarm64')

On second thought, these are not quite right. I think HOST_ARCH limit
to "aarch64" is ok but will still cause this to run on x86_64 build machines
which will not work. I think I need to add a BUILD_ARCH decorator to limit this to
run on 'aarch64' build host when building 'aarch64' targets. Then
KVM can work.

I'll update the changes.

Cheers,

-Mikko

> +    @OETestTag("runqemu")
> +    def test_boot_uboot_kvm_to_full_target(self):
> +        """
> +        Tests building u-boot and booting it with QEMU and KVM.
> +        Requires working KVM on build host. See "kvm-ok" output.
> +        """
> +
> +        runCmd("kvm-ok")
> +
> +        self.write_config("""
> +QEMU_USE_KVM = "1"
> +
> +# Using u-boot in EFI mode, need ESP partition for grub/systemd-boot/kernel etc
> +IMAGE_FSTYPES:pn-core-image-minimal:append = " wic"
> +
> +# easiest to follow genericarm64 setup with wks file, initrd and EFI loader
> +INITRAMFS_IMAGE="core-image-initramfs-boot"
> +EFI_PROVIDER = "${@bb.utils.contains("DISTRO_FEATURES", "systemd", "systemd-boot", "grub-efi", d)}"
> +WKS_FILE = "genericarm64.wks.in"
> +
> +# use wic image with ESP for u-boot, not ext4
> +QB_DEFAULT_FSTYPE = "wic"
> +
> +PREFERRED_PROVIDER_virtual/bootloader = "u-boot"
> +QB_DEFAULT_BIOS = "u-boot.bin"
> +
> +# let u-boot or EFI loader load kernel from ESP
> +QB_DEFAULT_KERNEL = "none"
> +
> +# virt pci, not scsi because support not in u-boot to find ESP
> +QB_DRIVE_TYPE = "vd"
> +# qemu usb causes u-boot reset atm
> +QB_OPT_APPEND = ""
> +""")
> +        bitbake("virtual/bootloader core-image-minimal")
> +
> +        runqemu_params = get_bb_var('TEST_RUNQEMUPARAMS', "core-image-minimal") or ""
> +        with runqemu('core-image-minimal', ssh=False, runqemuparams='nographic kvm %s' % runqemu_params) as qemu:
> +
> +            # boot to target and login worked, should have been fast with kvm
> +            cmd = "dmesg"
> +            status, output = qemu.run_serial(cmd)
> +            self.assertEqual(status, 1, msg=output)
> +            # Machine is qemu
> +            self.assertTrue("Machine model: linux,dummy-virt" in output, msg=output)
> +            # with KVM enabled
> +            self.assertTrue("KVM: hypervisor services detected" in output, msg=output)
> -- 
> 2.43.0
> 

> 
> -=-=-=-=-=-=-=-=-=-=-=-
> Links: You receive all messages sent to this group.
> View/Reply Online (#217107): https://lists.openembedded.org/g/openembedded-core/message/217107
> Mute This Topic: https://lists.openembedded.org/mt/113247084/7159507
> Group Owner: openembedded-core+owner@lists.openembedded.org
> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [mikko.rapeli@linaro.org]
> -=-=-=-=-=-=-=-=-=-=-=-
>