Magisk/scripts/boot_patch.sh
2023-06-14 17:05:49 -07:00

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#!/system/bin/sh
#######################################################################################
# Magisk Boot Image Patcher
#######################################################################################
#
# Usage: boot_patch.sh <bootimage>
#
# The following flags can be set in environment variables:
# KEEPVERITY, KEEPFORCEENCRYPT, PATCHVBMETAFLAG, RECOVERYMODE, SYSTEM_ROOT
#
# This script should be placed in a directory with the following files:
#
# File name Type Description
#
# boot_patch.sh script A script to patch boot image for Magisk.
# (this file) The script will use files in its same
# directory to complete the patching process.
# util_functions.sh script A script which hosts all functions required
# for this script to work properly.
# magiskinit binary The binary to replace /init.
# magisk(32/64) binary The magisk binaries.
# magiskboot binary A tool to manipulate boot images.
# stub.apk binary The stub Magisk app to embed into ramdisk.
# chromeos folder This folder includes the utility and keys to sign
# (optional) chromeos boot images. Only used for Pixel C.
#
#######################################################################################
############
# Functions
############
# Pure bash dirname implementation
getdir() {
case "$1" in
*/*)
dir=${1%/*}
if [ -z $dir ]; then
echo "/"
else
echo $dir
fi
;;
*) echo "." ;;
esac
}
#################
# Initialization
#################
if [ -z $SOURCEDMODE ]; then
# Switch to the location of the script file
cd "$(getdir "${BASH_SOURCE:-$0}")"
# Load utility functions
. ./util_functions.sh
# Check if 64-bit
api_level_arch_detect
fi
BOOTIMAGE="$1"
[ -e "$BOOTIMAGE" ] || abort "$BOOTIMAGE does not exist!"
# Dump image for MTD/NAND character device boot partitions
if [ -c "$BOOTIMAGE" ]; then
nanddump -f boot.img "$BOOTIMAGE"
BOOTNAND="$BOOTIMAGE"
BOOTIMAGE=boot.img
fi
# Flags
[ -z $KEEPVERITY ] && KEEPVERITY=false
[ -z $KEEPFORCEENCRYPT ] && KEEPFORCEENCRYPT=false
[ -z $PATCHVBMETAFLAG ] && PATCHVBMETAFLAG=false
[ -z $RECOVERYMODE ] && RECOVERYMODE=false
[ -z $SYSTEM_ROOT ] && SYSTEM_ROOT=false
export KEEPVERITY
export KEEPFORCEENCRYPT
export PATCHVBMETAFLAG
chmod -R 755 .
#########
# Unpack
#########
CHROMEOS=false
ui_print "- Unpacking boot image"
./magiskboot unpack "$BOOTIMAGE"
case $? in
0 ) ;;
1 )
abort "! Unsupported/Unknown image format"
;;
2 )
ui_print "- ChromeOS boot image detected"
CHROMEOS=true
;;
* )
abort "! Unable to unpack boot image"
;;
esac
###################
# Ramdisk Restores
###################
# Test patch status and do restore
ui_print "- Checking ramdisk status"
if [ -e ramdisk.cpio ]; then
./magiskboot cpio ramdisk.cpio test
STATUS=$?
else
# Stock A only legacy SAR, or some Android 13 GKIs
STATUS=0
fi
case $((STATUS & 3)) in
0 ) # Stock boot
ui_print "- Stock boot image detected"
SHA1=$(./magiskboot sha1 "$BOOTIMAGE" 2>/dev/null)
cat $BOOTIMAGE > stock_boot.img
cp -af ramdisk.cpio ramdisk.cpio.orig 2>/dev/null
;;
1 ) # Magisk patched
ui_print "- Magisk patched boot image detected"
./magiskboot cpio ramdisk.cpio \
"extract .backup/.magisk config.orig" \
"restore"
cp -af ramdisk.cpio ramdisk.cpio.orig
rm -f stock_boot.img
;;
2 ) # Unsupported
ui_print "! Boot image patched by unsupported programs"
abort "! Please restore back to stock boot image"
;;
esac
# Workaround custom legacy Sony /init -> /(s)bin/init_sony : /init.real setup
INIT=init
if [ $((STATUS & 4)) -ne 0 ]; then
INIT=init.real
fi
if [ -f config.orig ]; then
# Read existing configs
chmod 0644 config.orig
SHA1=$(grep_prop SHA1 config.orig)
if ! $BOOTMODE; then
# Do not inherit config if not in recovery
PREINITDEVICE=$(grep_prop PREINITDEVICE config.orig)
fi
rm config.orig
fi
##################
# Ramdisk Patches
##################
ui_print "- Patching ramdisk"
# Compress to save precious ramdisk space
SKIP32="#"
SKIP64="#"
if [ -f magisk64 ]; then
$BOOTMODE && [ -z "$PREINITDEVICE" ] && PREINITDEVICE=$(./magisk64 --preinit-device)
./magiskboot compress=xz magisk64 magisk64.xz
unset SKIP64
fi
if [ -f magisk32 ]; then
$BOOTMODE && [ -z "$PREINITDEVICE" ] && PREINITDEVICE=$(./magisk32 --preinit-device)
./magiskboot compress=xz magisk32 magisk32.xz
unset SKIP32
fi
./magiskboot compress=xz stub.apk stub.xz
echo "KEEPVERITY=$KEEPVERITY" > config
echo "KEEPFORCEENCRYPT=$KEEPFORCEENCRYPT" >> config
echo "PATCHVBMETAFLAG=$PATCHVBMETAFLAG" >> config
echo "RECOVERYMODE=$RECOVERYMODE" >> config
if [ -n "$PREINITDEVICE" ]; then
ui_print "- Pre-init storage partition: $PREINITDEVICE"
echo "PREINITDEVICE=$PREINITDEVICE" >> config
fi
[ -n "$SHA1" ] && echo "SHA1=$SHA1" >> config
./magiskboot cpio ramdisk.cpio \
"add 0750 $INIT magiskinit" \
"mkdir 0750 overlay.d" \
"mkdir 0750 overlay.d/sbin" \
"$SKIP32 add 0644 overlay.d/sbin/magisk32.xz magisk32.xz" \
"$SKIP64 add 0644 overlay.d/sbin/magisk64.xz magisk64.xz" \
"add 0644 overlay.d/sbin/stub.xz stub.xz" \
"patch" \
"backup ramdisk.cpio.orig" \
"mkdir 000 .backup" \
"add 000 .backup/.magisk config" \
|| abort "! Unable to patch ramdisk"
rm -f ramdisk.cpio.orig config magisk*.xz stub.xz
#################
# Binary Patches
#################
for dt in dtb kernel_dtb extra; do
if [ -f $dt ]; then
if ! ./magiskboot dtb $dt test; then
ui_print "! Boot image $dt was patched by old (unsupported) Magisk"
abort "! Please try again with *unpatched* boot image"
fi
if ./magiskboot dtb $dt patch; then
ui_print "- Patch fstab in boot image $dt"
fi
fi
done
if [ -f kernel ]; then
PATCHEDKERNEL=false
# Remove Samsung RKP
./magiskboot hexpatch kernel \
49010054011440B93FA00F71E9000054010840B93FA00F7189000054001840B91FA00F7188010054 \
A1020054011440B93FA00F7140020054010840B93FA00F71E0010054001840B91FA00F7181010054 \
&& PATCHEDKERNEL=true
# Remove Samsung defex
# Before: [mov w2, #-221] (-__NR_execve)
# After: [mov w2, #-32768]
./magiskboot hexpatch kernel 821B8012 E2FF8F12 && PATCHEDKERNEL=true
# Force kernel to load rootfs for legacy SAR devices
# skip_initramfs -> want_initramfs
$SYSTEM_ROOT && ./magiskboot hexpatch kernel \
736B69705F696E697472616D667300 \
77616E745F696E697472616D667300 \
&& PATCHEDKERNEL=true
# If the kernel doesn't need to be patched at all,
# keep raw kernel to avoid bootloops on some weird devices
$PATCHEDKERNEL || rm -f kernel
fi
#################
# Repack & Flash
#################
ui_print "- Repacking boot image"
./magiskboot repack "$BOOTIMAGE" || abort "! Unable to repack boot image"
# Sign chromeos boot
$CHROMEOS && sign_chromeos
# Restore the original boot partition path
[ -e "$BOOTNAND" ] && BOOTIMAGE="$BOOTNAND"
# Reset any error code
true