kxtzownsu
e8b6a73f87
(THIS COMMIT WILL NOT BUILD) changelog: - builder will now apply rootfs to image - builder has basic functions to shrink image
115 lines
2.5 KiB
Bash
115 lines
2.5 KiB
Bash
#!/bin/bash
|
|
# Code was borrowed from the SH1mmer repo, credits to them
|
|
# https://github.com/MercuryWorkshop/sh1mmer
|
|
|
|
is_ext2() {
|
|
local rootfs="$1"
|
|
local offset="${2-0}"
|
|
|
|
local sb_magic_offset=$((0x438))
|
|
local sb_value=$(dd if="$rootfs" skip=$((offset + sb_magic_offset)) \
|
|
count=2 bs=1 2>/dev/null)
|
|
local expected_sb_value=$(printf '\123\357')
|
|
if [ "$sb_value" = "$expected_sb_value" ]; then
|
|
return 0
|
|
fi
|
|
return 1
|
|
}
|
|
|
|
enable_rw_mount() {
|
|
local rootfs="$1"
|
|
local offset="${2-0}"
|
|
|
|
if ! is_ext2 "$rootfs" $offset; then
|
|
echo "enable_rw_mount called on non-ext2 filesystem: $rootfs $offset" 1>&2
|
|
return 1
|
|
fi
|
|
|
|
local ro_compat_offset=$((0x464 + 3))
|
|
printf '\000' |
|
|
dd of="$rootfs" seek=$((offset + ro_compat_offset)) \
|
|
conv=notrunc count=1 bs=1 2>/dev/null
|
|
}
|
|
|
|
disable_rw_mount() {
|
|
local rootfs="$1"
|
|
local offset="${2-0}"
|
|
|
|
if ! is_ext2 "$rootfs" $offset; then
|
|
echo "disable_rw_mount called on non-ext2 filesystem: $rootfs $offset" 1>&2
|
|
return 1
|
|
fi
|
|
|
|
local ro_compat_offset=$((0x464 + 3))
|
|
printf '\377' |
|
|
dd of="$rootfs" seek=$((offset + ro_compat_offset)) \
|
|
conv=notrunc count=1 bs=1 2>/dev/null
|
|
}
|
|
|
|
shrink_partitions() {
|
|
local shim="$1"
|
|
fdisk "$shim" <<EOF
|
|
d
|
|
12
|
|
d
|
|
11
|
|
d
|
|
10
|
|
d
|
|
9
|
|
d
|
|
8
|
|
d
|
|
7
|
|
d
|
|
6
|
|
d
|
|
5
|
|
d
|
|
4
|
|
d
|
|
1
|
|
p
|
|
w
|
|
EOF
|
|
}
|
|
|
|
truncate_image() {
|
|
local buffer=35
|
|
local sector_size=$("$SFDISK" -l "$1" | grep "Sector size" | awk '{print $4}')
|
|
local final_sector=$(get_final_sector "$1")
|
|
local end_bytes=$(((final_sector + buffer) * sector_size))
|
|
|
|
log "Truncating image to $(format_bytes "$end_bytes")"
|
|
truncate -s "$end_bytes" "$1"
|
|
|
|
# recreate backup gpt table/header
|
|
suppress sgdisk -e "$1" 2>&1 | sed 's/\a//g'
|
|
}
|
|
|
|
format_bytes() {
|
|
numfmt --to=iec-i --suffix=B "$@"
|
|
}
|
|
|
|
shrink_root() {
|
|
log "Shrinking ROOT-A Partition"
|
|
|
|
enable_rw_mount "${LOOPDEV}p3"
|
|
suppress e2fsck -fy "${LOOPDEV}p3"
|
|
suppress resize2fs -M "${LOOPDEV}p3"
|
|
disable_rw_mount "${LOOPDEV}p3"
|
|
|
|
local sector_size=$(get_sector_size "$LOOPDEV")
|
|
local block_size=$(tune2fs -l "${LOOPDEV}p3" | grep "Block size" | awk '{print $3}')
|
|
local block_count=$(tune2fs -l "${LOOPDEV}p3" | grep "Block count" | awk '{print $3}')
|
|
|
|
local original_sectors=$("$CGPT" show -i 3 -s -n -q "$LOOPDEV")
|
|
local original_bytes=$((original_sectors * sector_size))
|
|
|
|
local resized_bytes=$((block_count * block_size))
|
|
local resized_sectors=$((resized_bytes / sector_size))
|
|
|
|
echo "Resizing ROOT from $(format_bytes ${original_bytes}) to $(format_bytes ${resized_bytes})"
|
|
"$CGPT" add -i 3 -s "$resized_sectors" "$LOOPDEV"
|
|
partx -u -n 3 "$LOOPDEV"
|
|
} |