lsinitrd: update help message and man page

Signed-off-by: Kairui Song <kasong@redhat.com>

lsinitrd.1.asc

@@ -34,11 +34,17 @@ OPTIONS
 **-k, --kver** _<kernel version>_::
     inspect the initramfs of <kernel version>.
 
+**-m, --mod**::
+    list dracut modules included of the initramfs image.
+
 **--unpack**::
     unpack the initramfs to the current directory, instead of displaying the contents.
+    If optional filenames are given, will only unpack specified files, else the whole image will be unpacked.
+    Won't unpack anything from early cpio part.
 
 **--unpackearly**::
     unpack the early microcode initramfs to the current directory, instead of displaying the contents.
+    Same as --unpack, but only unpack files from early cpio part.
 
 **-v, --verbose**::
     unpack verbosely

lsinitrd.sh

@@ -28,7 +28,10 @@ usage()
         echo "-m, --mod                   list modules."
         echo "-f, --file <filename>       print the contents of <filename>."
         echo "--unpack                    unpack the initramfs, instead of displaying the contents."
+        echo "                            If optional filenames are given, will only unpack specified files,"
+        echo "                            else the whole image will be unpacked. Won't unpack anything from early cpio part."
         echo "--unpackearly               unpack the early microcode part of the initramfs."
+        echo "                            Same as --unpack, but only unpack files from early cpio part."
         echo "-v, --verbose               unpack verbosely."
         echo "-k, --kver <kernel version> inspect the initramfs of <kernel version>."
         echo