Merge Magisk install zip into Magisk Manager

Distribute Magisk directly with Magisk Manager APK. The APK will
contain all required binaries and scripts for installation and
uninstallation. App versions will now align with Magisk releases.

Extra effort is spent to make the APK itself also a flashable zip that
can be used in custom recoveries, so those still prefer to install
Magisk with recoveries will not be affected with this change.

As a bonus, this makes the whole installation and uninstallation
process 100% offline. The existing Magisk Manager was not really
functional without an Internet connection, as the installation process
was highly tied to zips hosted on the server.

An additional bonus: since all binaries are now shipped as "native
libraries" of the APK, we can finally bump the target SDK version
higher than 28. The target SDK version was stuck at 28 for a long time
because newer SELinux restricts running executables from internal
storage. More details can be found here: https://github.com/termux/termux-app/issues/1072
The target SDK bump will be addressed in a future commit.

Co-authored with @vvb2060

scripts/magisk_uninstaller.sh

@@ -1,72 +1,75 @@
 #MAGISK
 ############################################
-#
-# Magisk Uninstaller
-# by topjohnwu
-#
+# Magisk Uninstaller (updater-script)
 ############################################
 
 ##############
 # Preparation
 ##############
 
-# This path should work in any cases
-TMPDIR=/dev/tmp
-
-INSTALLER=$TMPDIR/install
-CHROMEDIR=$INSTALLER/chromeos
-
 # Default permissions
 umask 022
 
 OUTFD=$2
-ZIP=$3
+APK="$3"
+COMMONDIR=$INSTALLER/assets
+CHROMEDIR=$INSTALLER/assets/chromeos
 
-if [ ! -f $INSTALLER/util_functions.sh ]; then
+if [ ! -f $COMMONDIR/util_functions.sh ]; then
   echo "! Unable to extract zip file!"
   exit 1
 fi
 
 # Load utility functions
-. $INSTALLER/util_functions.sh
+. $COMMONDIR/util_functions.sh
 
 setup_flashable
 
-print_title "Magisk Uninstaller"
+############
+# Detection
+############
+
+if echo $MAGISK_VER | grep -q '\.'; then
+  PRETTY_VER=$MAGISK_VER
+else
+  PRETTY_VER="$MAGISK_VER($MAGISK_VER_CODE)"
+fi
+print_title "Magisk $PRETTY_VER Uninstaller"
 
 is_mounted /data || mount /data || abort "! Unable to mount /data, please uninstall with Magisk Manager"
+mount_partitions
+check_data
+$DATA_DE || abort "! Cannot access /data, please uninstall with Magisk Manager"
 if ! $BOOTMODE; then
   # Mounting stuffs in recovery (best effort)
   mount_name metadata /metadata
   mount_name "cache cac" /cache
   mount_name persist /persist
 fi
-mount_partitions
+get_flags
+find_boot_image
 
+[ -z $BOOTIMAGE ] && abort "! Unable to detect target image"
+ui_print "- Target image: $BOOTIMAGE"
+
+# Detect version and architecture
 api_level_arch_detect
 
 ui_print "- Device platform: $ARCH"
-MAGISKBIN=$INSTALLER/$ARCH32
-mv $CHROMEDIR $MAGISKBIN
-chmod -R 755 $MAGISKBIN
 
-check_data
-$DATA_DE || abort "! Cannot access /data, please uninstall with Magisk Manager"
-$BOOTMODE || recovery_actions
-run_migrations
+BINDIR=$INSTALLER/lib/$ARCH32
+[ ! -d "$BINDIR" ] && BINDIR=$INSTALLER/lib/armeabi-v7a
+cd $BINDIR
+for file in lib*.so; do mv "$file" "${file:3:${#file}-6}"; done
+cd /
+chmod -R 755 $CHROMEDIR $BINDIR
+cp -af $CHROMEDIR/. $BINDIR/chromeos
 
 ############
 # Uninstall
 ############
 
-get_flags
-find_boot_image
-
-[ -e $BOOTIMAGE ] || abort "! Unable to detect boot image"
-ui_print "- Found target image: $BOOTIMAGE"
-[ -z $DTBOIMAGE ] || ui_print "- Found dtbo image: $DTBOIMAGE"
-
-cd $MAGISKBIN
+cd $BINDIR
 
 CHROMEOS=false
 
@@ -108,14 +111,14 @@ case $((STATUS & 3)) in
   1 )  # Magisk patched
     ui_print "- Magisk patched image detected"
     # Find SHA1 of stock boot image
-    SHA1=`./magiskboot cpio ramdisk.cpio sha1 2>/dev/null`
+    SHA1=$(./magiskboot cpio ramdisk.cpio sha1 2>/dev/null)
     BACKUPDIR=/data/magisk_backup_$SHA1
     if [ -d $BACKUPDIR ]; then
       ui_print "- Restoring stock boot image"
       flash_image $BACKUPDIR/boot.img.gz $BOOTIMAGE
       for name in dtb dtbo dtbs; do
         [ -f $BACKUPDIR/${name}.img.gz ] || continue
-        IMAGE=`find_block $name$SLOT`
+        IMAGE=$(find_block $name$SLOT)
         [ -z $IMAGE ] && continue
         ui_print "- Restoring stock $name image"
         flash_image $BACKUPDIR/${name}.img.gz $IMAGE
@@ -124,7 +127,7 @@ case $((STATUS & 3)) in
       ui_print "! Boot image backup unavailable"
       ui_print "- Restoring ramdisk with internal backup"
       ./magiskboot cpio ramdisk.cpio restore
-      if ! ./magiskboot cpio ramdisk.cpio "exists init.rc"; then
+      if ! ./magiskboot cpio ramdisk.cpio "exists init"; then
         # A only system-as-root
         rm -f ramdisk.cpio
       fi
@@ -148,10 +151,11 @@ rm -rf \
 /data/adb/post-fs-data.d /data/adb/service.d /data/adb/modules* \
 /data/unencrypted/magisk /metadata/magisk /persist/magisk /mnt/vendor/persist/magisk
 
-if [ -f /system/addon.d/99-magisk.sh ]; then
+ADDOND=/system/addon.d/99-magisk.sh
+if [ -f $ADDOND ]; then
   blockdev --setrw /dev/block/mapper/system$SLOT 2>/dev/null
   mount -o rw,remount /system || mount -o rw,remount /
-  rm -f /system/addon.d/99-magisk.sh
+  rm -f $ADDOND
 fi
 
 cd /
@@ -163,7 +167,10 @@ if $BOOTMODE; then
   ui_print "********************************************"
   (sleep 8; /system/bin/reboot)&
 else
-  rm -rf /data/data/*magisk* /data/user*/*/*magisk* /data/app/*magisk* /data/app/*/*magisk*
+  ui_print "********************************************"
+  ui_print " Magisk Manager will not be uninstalled"
+  ui_print " Please uninstall it manually after reboot"
+  ui_print "********************************************"
   recovery_cleanup
   ui_print "- Done"
 fi