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>
(From OE-Core rev: c5fa4320e666a0606b18be8f0a08e659170568f2)

Signed-off-by: Mikko Rapeli <mikko.rapeli@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 5 insertions, 0 deletions

diff --git a/meta/recipes-bsp/u-boot/files/disable-CONFIG_BLOBLIST.cfg b/meta/recipes-bsp/u-boot/files/disable-CONFIG_BLOBLIST.cfg
new file mode 100644
index 0000000000..d01d3d12d8
--- /dev/null
+++ b/meta/recipes-bsp/u-boot/files/disable-CONFIG_BLOBLIST.cfg
@@ -0,0 +1 @@
+# CONFIG_BLOBLIST is not set
diff --git a/meta/recipes-bsp/u-boot/u-boot-common.inc b/meta/recipes-bsp/u-boot/u-boot-common.inc
index fd1eab5cdd..a77c49cb8b 100644
--- a/meta/recipes-bsp/u-boot/u-boot-common.inc
+++ b/meta/recipes-bsp/u-boot/u-boot-common.inc
@@ -16,6 +16,10 @@ SRCREV = "34820924edbc4ec7803eb89d9852f4b870fa760a"
 
 SRC_URI = "git://source.denx.de/u-boot/u-boot.git;protocol=https;branch=master;tag=v${PV}"
 
+# workaround for aarch64 kvm qemu boot regression
+SRC_URI:append:qemuarm64 = " file://disable-CONFIG_BLOBLIST.cfg"
+SRC_URI:append:genericarm64 = " file://disable-CONFIG_BLOBLIST.cfg"
+
 S = "${WORKDIR}/git"
 B = "${WORKDIR}/build"