1 files changed, 102 insertions, 0 deletions

diff --git a/recipes/initramfs-basic/files/init.sh b/recipes/initramfs-basic/files/init.sh
new file mode 100644
index 0000000..3db235b
--- /dev/null
+++ b/recipes/initramfs-basic/files/init.sh
@@ -0,0 +1,102 @@
+#!/bin/sh
+
+PATH=/sbin:/bin:/usr/sbin:/usr/bin
+ROOT_MOUNT="/sysroot/"
+ROOT_DEVICE=""
+
+early_setup() {
+
+    mkdir -p /proc
+    mkdir -p /sys
+    mount -t proc proc /proc
+    mount -t sysfs sysfs /sys
+    mount -t devtmpfs none /dev
+
+    mkdir -p /run
+    mkdir -p /var/run
+}
+
+read_args() {
+
+    for arg in $(cat /proc/cmdline); do
+        value=$(echo ${arg} | cut -s -f2- -d '=')
+        case $arg in
+            root=*)
+                root=$value
+                ;;
+            debugshell*)
+                if [ -z "$value" ]; then
+                     shelltimeout=30
+                else
+                     shelltimeout=$value
+                fi
+                ;;
+        esac
+    done
+
+    if [ -z "$root" ] ; then
+        debug_shell "No root= specified via kernel command line."
+    else
+        case $root in
+            LABEL=*)
+                label=${root#LABEL=}
+                ;;
+            *)
+                debug_shell "This init script only supports root=LABEL=* for specifying root file system, but root=$root was provided."
+                ;;
+        esac
+    fi
+}
+
+mount_rootfs() {
+
+    mkdir -p $ROOT_MOUNT
+    mount $ROOT_DEVICE $ROOT_MOUNT
+    mount -n --move /proc $ROOT_MOUNT/proc
+    mount -n --move /sys $ROOT_MOUNT/sys
+    mount -n --move /dev $ROOT_MOUNT/dev
+
+    exec switch_root $ROOT_MOUNT /sbin/init || debug_shell "Couldn't switch_root."
+}
+
+switch_real_root() {
+
+    echo "Searching for media..."
+    C=0
+    while true
+    do
+
+    rootfs=$(findfs LABEL=$label)
+    if [ -n "$rootfs" ] ; then
+        ROOT_DEVICE=$rootfs
+        mount_rootfs
+    fi
+
+    # don't wait for more than $shelltimeout seconds, if it's set
+    if [ -n "$shelltimeout" ]; then
+        echo -n " " $(( $shelltimeout - $C ))
+        if [ $C -ge $shelltimeout ]; then
+            debug_shell "Cannot find root file system."
+        fi
+        C=$(( C + 1 ))
+    fi
+
+    sleep 1
+    done
+}
+
+debug_shell() {
+
+    echo ${1}
+    echo "Dropping to a shell."
+    exec sh
+}
+
+main() {
+
+    early_setup
+    read_args
+    switch_real_root
+}
+
+main