initramfs-boot-android: New generic init.sh that boots from /sdcard/asteroidos.ext4

recipes-core/initrdscripts/initramfs-boot-android/init.sh

+#! /bin/sh
+
+# machine.conf should provide $sdcard_partition
+. /machine.conf
+
+# Logging functions
+info() {
+    echo "$1" > /dev/ttyprintk
+}
+
+fail() {
+    echo "Failed" > /dev/ttyprintk
+    echo "$1" > /dev/ttyprintk
+    echo "Waiting for 15 seconds before rebooting ..." > /dev/ttyprintk
+    sleep 15s
+    reboot
+}
+
+# Populates /dev (called for /dev and /rfs/dev)
+setup_devtmpfs() {
+    mount -t devtmpfs -o mode=0755,nr_inodes=0 devtmpfs $1/dev
+
+    mkdir $1/dev/pts
+    mount -t devpts none $1/dev/pts/
+
+    test -c $1/dev/fd     || ln -sf /proc/self/fd $1/dev/fd
+    test -c $1/dev/stdin  || ln -sf fd/0 $1/dev/stdin
+    test -c $1/dev/stdout || ln -sf fd/1 $1/dev/stdout
+    test -c $1/dev/stderr || ln -sf fd/2 $1/dev/stderr
+    test -c $1/dev/socket || mkdir -m 0755 $1/dev/socket
+}
+
+echo "Mounting relevant filesystems ..."
+mkdir -m 0755 /proc
+mount -t proc proc /proc
+mkdir -m 0755 /sys
+mount -t sysfs sys /sys
+mkdir -p /dev
+setup_devtmpfs ""
+
+# Checks wether we need to start adbd for interactive debugging
+cat /proc/cmdline | grep debug-ramdisk
+if [ $? -ne 1 ] ; then
+    mkdir -p /dev/usb-ffs/adb
+    mount -t functionfs adb /dev/usb-ffs/adb
+
+    echo 0 > /sys/class/android_usb/android0/enable
+    echo 18d1 > /sys/class/android_usb/android0/idVendor
+    echo d002 > /sys/class/android_usb/android0/idProduct
+    echo adb > /sys/class/android_usb/android0/f_ffs/aliases
+    echo ffs > /sys/class/android_usb/android0/functions
+    echo AsteroidOS > /sys/class/android_usb/android0/iManufacturer
+    echo InitRamDisk > /sys/class/android_usb/android0/iProduct
+    serial="$(cat /proc/cmdline | sed 's/.*androidboot.serialno=//' | sed 's/ .*//')"
+    echo $serial > /sys/class/android_usb/android0/iSerial
+    echo 1 > /sys/class/android_usb/android0/enable
+
+    /usr/bin/android-gadget-setup adb
+    /usr/bin/adbd
+fi
+
+# The sdcard partition may be the rootfs itself or contain a loop file
+info "Mounting sdcard..."
+mkdir -m 0777 /sdcard /loop
+
+while [ ! -e /sys/block/mmcblk0 ] ; do
+    info "Waiting for mmcblk0..."
+    sleep 1
+done
+mount -t auto -o rw,noatime,nodiratime /dev/$sdcard_partition /sdcard
+[ $? -eq 0 ] || fail "Failed to mount the sdcard. Cannot continue."
+
+info "Checking for loop rootfs image on the sdcard..."
+ANDROID_MEDIA_DIR="/sdcard/media/"
+if [ -d /sdcard/media/0 ] ; then
+    ANDROID_MEDIA_DIR="/sdcard/media/0"
+fi
+
+BOOT_DIR="/sdcard"
+if [ -e $ANDROID_MEDIA_DIR/asteroidos.ext4 ] ; then
+    # Boots from a /sdcard/asteroidos.ext4 loop file
+    info "Rootfs image found at $ANDROID_MEDIA_DIR/asteroidos.ext4; mounting it now ..."
+    mount -o noatime,nodiratime,sync,rw,loop $ANDROID_MEDIA_DIR/asteroidos.ext4 /loop
+    [ $? -ne 0 ] || BOOT_DIR="/loop"
+fi
+
+setup_devtmpfs $BOOT_DIR
+
+info "Move the /proc and /sys filesystems..."
+umount -l /proc
+umount -l /sys
+mount -t proc proc $BOOT_DIR/proc
+mount -t sysfs sys $BOOT_DIR/sys
+
+info "Switching to rootfs..."
+exec switch_root -c /dev/ttyprintk $BOOT_DIR /lib/systemd/systemd > /dev/ttyprintk