Boot fixes: drop the stock BLS entry, define load_video, set kernel cmdline

First boot on the hardware failed, returning to the GRUB menu with:

    can't find command 'load_video'
    file '/boot/vmlinuz-7.1.5-200.fc44.aarch64' not found
    you need to load the kernel first

The title in that message was the tell: "Fedora Linux (7.1.5-...) 44 (Forty
Four)" is Fedora's stock format, not ours. GRUB was booting an entry we did not
write. Confirmed by unpacking the published image and reading the boot
filesystem — /loader/entries held two files, and the one named after the
machine-id sorts before c630-*, so it won.

kernel-install wrote it during the dnf transaction, from inside the install
root where /boot is an ordinary directory rather than a partition. It was wrong
three ways: paths of /boot/vmlinuz-… that resolve nowhere once /boot is its own
filesystem; an empty options line, so no root= and no command line at all; and
no devicetree, so even had it loaded, the kernel would not have known what
machine it was on. Ours, sitting right beside it, was correct throughout.

So: delete any entry we did not write, and define load_video in grub.cfg —
blscfg emits menuentries that call it, and Fedora's generated config defines it
where a hand-written one must too.

Also write /etc/kernel/cmdline. That empty options line was not a build-time
quirk; it is what kernel-install produces when nothing tells it the command
line. The same gap would have bitten on the device at the first
`dnf update kernel`, writing an entry with no root= and no C630 quirks, and the
laptop would not have come back.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XWRjNJMistCy6ngXH5aJLS

build/stage2.sh

@@ -245,6 +245,15 @@ UUID=${BOOT_UUID}  /boot      ext4  defaults              1 2
 UUID=${ESP_UUID}   /boot/efi  vfat  umask=0077,shortname=winnt 0 2
 EOF
 
+# The entry kernel-install wrote during the transaction had an empty options
+# line, because nothing told it what the command line should be. That same gap
+# would bite on the device: the first `dnf update kernel` would write an entry
+# with no root= and no C630 quirks, and the machine would not come back. This is
+# where kernel-install looks.
+mkdir -p "$ROOTFS/etc/kernel"
+printf 'root=UUID=%s ro %s\n' "$ROOT_UUID" "$DEVICE_CMDLINE" \
+    > "$ROOTFS/etc/kernel/cmdline"
+
 # Empty (not missing) machine-id marks this as a first boot for systemd, which
 # then generates a unique one per device rather than cloning the builder's.
 : > "$ROOTFS/etc/machine-id"
@@ -290,9 +299,19 @@ chroot "$ROOTFS" dracut --force --no-hostonly --no-hostonly-cmdline \
 # ---------------------------------------------------------------------------
 log "Writing bootloader configuration"
 # ---------------------------------------------------------------------------
+mkdir -p "$ROOTFS/boot/loader/entries"
+
+# kernel-install already wrote an entry during the dnf transaction, from inside
+# the install root — where /boot is an ordinary directory, not a partition. It
+# is wrong in three ways: its paths are /boot/vmlinuz-… which resolve nowhere
+# once /boot is a filesystem in its own right; its options line is empty, so no
+# root= and no command line; and it has no devicetree, so even if it loaded, the
+# kernel would not know what machine it was on. Being named after the machine-id
+# it also sorts before ours, so GRUB picks it. Delete anything we did not write.
+rm -f "$ROOTFS/boot/loader/entries/"*.conf
+
 # The bootstrap BLS entry. Subsequent kernels get theirs from kernel-install,
 # with the devicetree line supplied by 95-c630-devicetree.install.
-mkdir -p "$ROOTFS/boot/loader/entries"
 cat > "$ROOTFS/boot/loader/entries/c630-${KVER}.conf" <<EOF
 title Fedora Linux ${FEDORA_RELEASE} (${KVER}) — ${DEVICE_DESC}
 version ${KVER}
@@ -320,6 +339,19 @@ insmod all_video
 insmod gzio
 insmod blscfg
 
+# blscfg turns each BLS entry into a menuentry that calls load_video before
+# loading the kernel. Fedora's generated grub.cfg defines it; a hand-written one
+# has to as well, or every entry fails with "can't find command 'load_video'".
+function load_video {
+  if [ x\$feature_all_video_module = xy ]; then
+    insmod all_video
+  else
+    insmod efi_gop
+    insmod video_bochs
+    insmod video_cirrus
+  fi
+}
+
 search --no-floppy --fs-uuid --set=root ${BOOT_UUID}
 
 if [ -s \$prefix/grubenv ]; then