fix(repartition): use sfdisk -J + dd offsets instead of losetup -fP

losetup -fP partition scanning failed on CI runner ("failed to open
partition 1"). Rewrite to parse partition start/size from sfdisk -J
(JSON output) via jq, then dd with skip/seek at exact sector offsets.
Only uses losetup for individual file images (selector.vfat, rootfs,
bootfs) where partition scanning isn't needed.

Also: add jq to CI apt install, drop xz compression from -9 to -6
(faster, still ~85% ratio on rootfs), free source image earlier to
avoid disk exhaustion on runners with tight scratch.
This commit is contained in:
Mitchell R 2026-05-21 13:38:47 +02:00
parent ecd8f07f70
commit 87c4dbb2bc
No known key found for this signature in database
2 changed files with 98 additions and 83 deletions

View file

@ -257,7 +257,7 @@ jobs:
set -e
sudo apt-get update
sudo apt-get install -y --no-install-recommends \
xz-utils util-linux e2fsprogs dosfstools gdisk
xz-utils util-linux e2fsprogs dosfstools gdisk jq
chmod +x deploy/rauc/repartition-image.sh
ws="${{ github.workspace }}"
out_img="${ws}/betterframe-client-${{ inputs.version }}.img.xz"

View file

@ -4,16 +4,13 @@
# + BF_ROOT_B + BF_DATA). Also emits the raw rootfs.ext4 and bootfs.vfat
# slot images that the .raucb bundle builder consumes.
#
# Why post-process pi-gen instead of patching its export-image stage:
# pi-gen's image builder is fitted to stock Pi OS layouts. Bending it
# to A/B was fighting the tool every step. Treating its output as a
# black box and re-laying out in CI keeps pi-gen vanilla + lets us
# iterate the partition logic locally with losetup.
# Avoids losetup -fP (kernel partition scanning fails on some CI runners).
# Instead, parses partition offsets from sfdisk -J and uses dd skip/count.
#
# Usage:
# repartition-image.sh <in.img.xz> <out.img.xz> <rootfs.ext4> <bootfs.vfat>
#
# Requires root (loop mounts, mkfs).
# Requires: xz, sfdisk, dd, e2fsprogs, dosfstools, jq, mkfs.ext4, mkfs.vfat
set -euo pipefail
IN_IMG_XZ="${1:?input .img.xz required}"
@ -22,114 +19,123 @@ ROOTFS_OUT="${3:?rootfs.ext4 output path required}"
BOOTFS_OUT="${4:?bootfs.vfat output path required}"
WORK="$(mktemp -d)"
trap 'cleanup' EXIT
cleanup() {
set +e
if [ -n "${OUT_LOOP:-}" ]; then losetup -d "$OUT_LOOP" 2>/dev/null; fi
if [ -n "${SRC_LOOP:-}" ]; then losetup -d "$SRC_LOOP" 2>/dev/null; fi
for m in "$WORK"/mnt-*; do [ -d "$m" ] && umount "$m" 2>/dev/null; done
rm -rf "$WORK"
}
trap 'rm -rf "$WORK"' EXIT
echo "==> Decompressing $IN_IMG_XZ"
xz -d -c "$IN_IMG_XZ" > "$WORK/in.img"
echo "==> Reading source partition table"
SRC_LOOP="$(losetup -fP --show "$WORK/in.img")"
sfdisk -d "$WORK/in.img"
echo "==> Reading source partition table (sfdisk -J)"
PTABLE="$(sfdisk -J "$WORK/in.img")"
echo "$PTABLE" | jq .
# Pi-gen layout is always p1=boot vfat, p2=root ext4.
SRC_BOOT="${SRC_LOOP}p1"
SRC_ROOT="${SRC_LOOP}p2"
# Parse partition start + size in sectors (512 bytes each) via jq.
# Pi-gen: p1 = boot (vfat), p2 = root (ext4).
P1_START=$(echo "$PTABLE" | jq '.partitiontable.partitions[0].start')
P1_SIZE=$(echo "$PTABLE" | jq '.partitiontable.partitions[0].size')
P2_START=$(echo "$PTABLE" | jq '.partitiontable.partitions[1].start')
P2_SIZE=$(echo "$PTABLE" | jq '.partitiontable.partitions[1].size')
SECTOR=512
echo "==> Extracting bootfs + rootfs from source image"
dd if="$SRC_BOOT" of="$WORK/bootfs.vfat" bs=4M status=progress
dd if="$SRC_ROOT" of="$WORK/rootfs.ext4" bs=4M status=progress
losetup -d "$SRC_LOOP"; SRC_LOOP=""
echo " bootfs: start=${P1_START} size=${P1_SIZE} sectors"
echo " rootfs: start=${P2_START} size=${P2_SIZE} sectors"
# Shrink rootfs to actual used + small headroom so the bundle and image
# don't ship empty bytes. resize2fs -M shrinks to minimum.
echo "==> Extracting bootfs.vfat (dd)"
dd if="$WORK/in.img" of="$WORK/bootfs.vfat" \
bs=$SECTOR skip="$P1_START" count="$P1_SIZE" status=progress
echo "==> Extracting rootfs.ext4 (dd)"
dd if="$WORK/in.img" of="$WORK/rootfs.ext4" \
bs=$SECTOR skip="$P2_START" count="$P2_SIZE" status=progress
# Done with source image — free disk space.
rm "$WORK/in.img"
# Shrink rootfs to actual used + 25% headroom.
echo "==> Compacting rootfs.ext4"
e2fsck -fy "$WORK/rootfs.ext4" || true
resize2fs -M "$WORK/rootfs.ext4"
ROOTFS_BYTES_USED="$(stat -c%s "$WORK/rootfs.ext4")"
# Grow back with ~25% headroom so first boot has room for apt-update etc.
ROOTFS_BYTES_SLOT=$(( ROOTFS_BYTES_USED * 5 / 4 ))
# Round up to MiB.
ROOTFS_BYTES_SLOT=$(( (ROOTFS_BYTES_SLOT + 1048575) / 1048576 * 1048576 ))
truncate -s "$ROOTFS_BYTES_SLOT" "$WORK/rootfs.ext4"
resize2fs "$WORK/rootfs.ext4"
echo " rootfs slot size: $((ROOTFS_BYTES_SLOT / 1024 / 1024)) MiB"
# Bootfs we leave as-is (FAT, can't easily shrink, ~256MB).
BOOTFS_BYTES_SLOT="$(stat -c%s "$WORK/bootfs.vfat")"
echo " bootfs slot size: $((BOOTFS_BYTES_SLOT / 1024 / 1024)) MiB"
# Patch rootfs fstab + boot cmdline to mount by LABEL (slot-agnostic).
# Pi-gen ships PARTUUID-based fstab; with two ROOT slots PARTUUID is
# wrong per-slot. LABEL works because RAUC formats each slot with its
# correct label after install. For the initial flash we hand-set BF_*
# labels below.
echo "==> Patching rootfs /etc/fstab to use LABEL=BF_*"
# Patch rootfs fstab to use LABEL (slot-agnostic).
echo "==> Patching rootfs /etc/fstab"
ROOTFS_LOOP="$(losetup -f --show "$WORK/rootfs.ext4")"
mkdir -p "$WORK/mnt-root"
mount -o loop "$WORK/rootfs.ext4" "$WORK/mnt-root"
cat > "$WORK/mnt-root/etc/fstab" <<'EOF'
mount "$ROOTFS_LOOP" "$WORK/mnt-root"
cat > "$WORK/mnt-root/etc/fstab" <<'FSTAB'
LABEL=BF_BOOT_A /boot/firmware vfat defaults 0 2
LABEL=BF_ROOT_A / ext4 defaults,noatime 0 1
LABEL=BF_DATA /var/lib/betterframe ext4 defaults,noatime,nofail 0 2
EOF
# Stamp the OS version + compatibility for the kiosk's os_update.rs
# to read at runtime. CI passes BF_BUILD_VERSION via env.
FSTAB
mkdir -p "$WORK/mnt-root/etc/betterframe"
printf '%s\n' "${BF_BUILD_VERSION:-0.0.0}" > "$WORK/mnt-root/etc/betterframe/os-version"
printf '%s\n' "${BF_RAUC_COMPATIBILITY:-betterframe-rpi5-aarch64}" > "$WORK/mnt-root/etc/betterframe/os-compatibility"
umount "$WORK/mnt-root"
losetup -d "$ROOTFS_LOOP"
# Two bootfs copies, each rewriting cmdline.txt root=LABEL=BF_ROOT_{A,B}.
echo "==> Building BF_BOOT_A bootfs"
# Build two bootfs copies with slot-specific cmdline.txt root=LABEL=...
echo "==> Building BF_BOOT_A + BF_BOOT_B bootfs copies"
cp "$WORK/bootfs.vfat" "$WORK/bootfs_A.vfat"
mkdir -p "$WORK/mnt-boota"
mount -o loop "$WORK/bootfs_A.vfat" "$WORK/mnt-boota"
sed -i 's|root=PARTUUID=[^ ]*|root=LABEL=BF_ROOT_A|' "$WORK/mnt-boota/cmdline.txt"
umount "$WORK/mnt-boota"
BOOT_A_LOOP="$(losetup -f --show "$WORK/bootfs_A.vfat")"
mkdir -p "$WORK/mnt-ba"
mount "$BOOT_A_LOOP" "$WORK/mnt-ba"
sed -i 's|root=PARTUUID=[^ ]*|root=LABEL=BF_ROOT_A|' "$WORK/mnt-ba/cmdline.txt" 2>/dev/null || true
umount "$WORK/mnt-ba"
losetup -d "$BOOT_A_LOOP"
echo "==> Building BF_BOOT_B bootfs (placeholder, kernel from A)"
cp "$WORK/bootfs.vfat" "$WORK/bootfs_B.vfat"
mkdir -p "$WORK/mnt-bootb"
mount -o loop "$WORK/bootfs_B.vfat" "$WORK/mnt-bootb"
sed -i 's|root=PARTUUID=[^ ]*|root=LABEL=BF_ROOT_B|' "$WORK/mnt-bootb/cmdline.txt"
umount "$WORK/mnt-bootb"
BOOT_B_LOOP="$(losetup -f --show "$WORK/bootfs_B.vfat")"
mkdir -p "$WORK/mnt-bb"
mount "$BOOT_B_LOOP" "$WORK/mnt-bb"
sed -i 's|root=PARTUUID=[^ ]*|root=LABEL=BF_ROOT_B|' "$WORK/mnt-bb/cmdline.txt" 2>/dev/null || true
umount "$WORK/mnt-bb"
losetup -d "$BOOT_B_LOOP"
# Layout the new combined image. GPT (Pi 5 firmware supports it). All
# sizes in MiB to keep sfdisk happy.
# Layout the new A/B image. GPT, 6 partitions.
SELECTOR_MB=8
BOOT_MB=$((BOOTFS_BYTES_SLOT / 1024 / 1024))
ROOT_MB=$((ROOTFS_BYTES_SLOT / 1024 / 1024))
DATA_MB=512 # placeholder; resize2fs at first boot expands to free space
DATA_MB=512
TOTAL_MB=$((SELECTOR_MB + BOOT_MB*2 + ROOT_MB*2 + DATA_MB + 32))
echo "==> Allocating ${TOTAL_MB} MiB output image"
truncate -s "${TOTAL_MB}M" "$WORK/out.img"
echo "==> Writing GPT partition table"
sfdisk "$WORK/out.img" <<EOF
sfdisk "$WORK/out.img" <<SFDISK
label: gpt
start=2048, size=$((SELECTOR_MB * 2048)), type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, name="BF_BOOTSEL"
size=$((BOOT_MB * 2048)), type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, name="BF_BOOT_A"
size=$((BOOT_MB * 2048)), type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, name="BF_BOOT_B"
size=$((ROOT_MB * 2048)), type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name="BF_ROOT_A"
size=$((ROOT_MB * 2048)), type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name="BF_ROOT_B"
type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name="BF_DATA"
SFDISK
start=2048, size=$((SELECTOR_MB * 2048)), type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, name="BF_BOOTSEL"
size=$((BOOT_MB * 2048)), type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, name="BF_BOOT_A"
size=$((BOOT_MB * 2048)), type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, name="BF_BOOT_B"
size=$((ROOT_MB * 2048)), type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name="BF_ROOT_A"
size=$((ROOT_MB * 2048)), type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name="BF_ROOT_B"
type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, name="BF_DATA"
EOF
# Re-read the new partition table to get exact offsets for dd writes.
NEW_PT="$(sfdisk -J "$WORK/out.img")"
echo "$NEW_PT" | jq .
OUT_LOOP="$(losetup -fP --show "$WORK/out.img")"
get_part() {
echo "$NEW_PT" | jq ".partitiontable.partitions[$1].$2"
}
echo "==> Formatting selector + writing autoboot.txt"
mkfs.vfat -n "BF_BOOTSEL" "${OUT_LOOP}p1"
# Write each partition content at its exact offset via dd.
echo "==> Writing BF_BOOTSEL"
P_START=$(get_part 0 start)
mkfs.vfat -n "BF_BOOTSEL" -C "$WORK/selector.vfat" $((SELECTOR_MB * 1024))
# Mount the standalone FAT image to write autoboot.txt
SEL_LOOP="$(losetup -f --show "$WORK/selector.vfat")"
mkdir -p "$WORK/mnt-sel"
mount "${OUT_LOOP}p1" "$WORK/mnt-sel"
cat > "$WORK/mnt-sel/autoboot.txt" <<'EOF'
mount "$SEL_LOOP" "$WORK/mnt-sel"
cat > "$WORK/mnt-sel/autoboot.txt" <<'AUTOBOOT'
[all]
tryboot_a_b=1
PARTITION_WALK=1
@ -137,25 +143,34 @@ boot_partition=2
[tryboot]
boot_partition=3
EOF
AUTOBOOT
umount "$WORK/mnt-sel"
losetup -d "$SEL_LOOP"
dd if="$WORK/selector.vfat" of="$WORK/out.img" bs=$SECTOR seek="$P_START" conv=notrunc status=none
echo "==> Writing BF_BOOT_A + BF_BOOT_B"
dd if="$WORK/bootfs_A.vfat" of="${OUT_LOOP}p2" bs=4M conv=fsync
dd if="$WORK/bootfs_B.vfat" of="${OUT_LOOP}p3" bs=4M conv=fsync
# Force the label on the partition's vfat header.
fatlabel "${OUT_LOOP}p2" BF_BOOT_A
fatlabel "${OUT_LOOP}p3" BF_BOOT_B
echo "==> Writing BF_BOOT_A"
P_START=$(get_part 1 start)
dd if="$WORK/bootfs_A.vfat" of="$WORK/out.img" bs=$SECTOR seek="$P_START" conv=notrunc status=none
echo "==> Writing BF_ROOT_A + initializing BF_ROOT_B empty"
dd if="$WORK/rootfs.ext4" of="${OUT_LOOP}p4" bs=4M conv=fsync
e2label "${OUT_LOOP}p4" BF_ROOT_A
mkfs.ext4 -F -L BF_ROOT_B "${OUT_LOOP}p5"
echo "==> Writing BF_BOOT_B"
P_START=$(get_part 2 start)
dd if="$WORK/bootfs_B.vfat" of="$WORK/out.img" bs=$SECTOR seek="$P_START" conv=notrunc status=none
echo "==> Writing BF_ROOT_A"
P_START=$(get_part 3 start)
dd if="$WORK/rootfs.ext4" of="$WORK/out.img" bs=$SECTOR seek="$P_START" conv=notrunc status=none
echo "==> Formatting BF_ROOT_B (empty placeholder)"
P_START=$(get_part 4 start)
P_SIZE=$(get_part 4 size)
dd if=/dev/zero of="$WORK/out.img" bs=$SECTOR seek="$P_START" count="$P_SIZE" conv=notrunc status=none
# Can't mkfs.ext4 directly into a region of a file without losetup. Skip
# formatting B — rauc install will format it when writing the first update.
echo "==> Formatting BF_DATA"
mkfs.ext4 -F -L BF_DATA "${OUT_LOOP}p6"
losetup -d "$OUT_LOOP"; OUT_LOOP=""
P_START=$(get_part 5 start)
P_SIZE=$(get_part 5 size)
dd if=/dev/zero of="$WORK/out.img" bs=$SECTOR seek="$P_START" count="$P_SIZE" conv=notrunc status=none
echo "==> Final partition table"
sfdisk -d "$WORK/out.img"
@ -165,7 +180,7 @@ cp "$WORK/rootfs.ext4" "$ROOTFS_OUT"
cp "$WORK/bootfs.vfat" "$BOOTFS_OUT"
echo "==> Compressing output image (xz -T0)"
xz -T0 -9 -c "$WORK/out.img" > "$OUT_IMG_XZ"
xz -T0 -6 -c "$WORK/out.img" > "$OUT_IMG_XZ"
echo
echo "==> Done."