add messages to dmesg about geninitrd startup and when it switches root

diff --git a/geninitrd b/geninitrd
index fe7e13efc3ef585ac4fe24a01c64516f1098ba21..44b254b7d3218eca5b390661e6aad429bf64d251 100755 (executable)
--- a/geninitrd
+++ b/geninitrd
@@ -86,6 +86,25 @@ debug() {
        [ x"$verbose" = x"-v -v" ] && msg "$*" >&3
 }
 
+# add initrd code to print to kmsg
+# @param string message
+# @param int loglevel. defaults to "6" (info)
+# Log levels can be:
+# Name         String  Meaning
+# KERN_EMERG   "0"     Emergency messages, system is about to crash or is unstable
+# KERN_ALERT   "1"     Something bad happened and action must be taken immediately
+# KERN_CRIT    "2"     A critical condition occurred like a serious hardware/software failure
+# KERN_ERR     "3"     An error condition, often used by drivers to indicate difficulties with the hardware
+# KERN_WARNING "4"     A warning, meaning nothing serious by itself but might indicate problems
+# KERN_NOTICE  "5"     Nothing serious, but notably nevertheless. Often used to report security events.
+# KERN_INFO    "6"     Informational message e.g. startup information at driver initialization
+# KERN_DEBUG   "7"     Debug messages
+# KERN_CONT    "c"     "continued" line of log printout (only done after a line that had no enclosing \n)
+kmsg() {
+       local msg="$1" level=${2:-6}
+       echo "echo '<$level>$msg' > /dev/kmsg" | add_linuxrc
+}
+
 # aborts program abnormally
 die() {
        local rc=${2:-1}
@@ -956,8 +975,11 @@ initrd_gen_initramfs_switchroot() {
                        echo "Last 20 lines of dmesg:"
                        dmesg | tail -n 20
                fi
+
        EOF
 
+       kmsg "geninitrd/$VERSION switching root"
+
        umount_all
        busybox_applet switch_root usleep
        add_linuxrc <<-'EOF'
@@ -1423,6 +1445,7 @@ mknod -m 666 "$DESTDIR/dev/null" c 1 3
 mknod -m 666 "$DESTDIR/dev/zero" c 1 5
 mknod -m 666 "$DESTDIR/dev/random" c 1 8
 mknod -m 666 "$DESTDIR/dev/urandom" c 1 9
+mknod -m 644 "$DESTDIR/dev/kmsg" c 1 11
 
 inst_exec $busybox /bin/busybox
 ln -s busybox $DESTDIR/bin/sh
@@ -1436,6 +1459,9 @@ add_linuxrc <<EOF
 
 EOF
 mount_proc
+
+kmsg "geninitrd/$VERSION starting"
+
 add_linuxrc <<-EOF
        # builtin defaults from geninitrd
        ROOT=$rootdev