Notes on boot images - There have the magic.

http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html



Usage:  bootimg-tools [actions] <switches>
Actions:
unpack		unpack a boot image into it's constituent parts
pack		pack seperate files into a boot image
list		print boot image header details or ramdisk fileinfo
extract   	extract a single file from a boot image ramdisk
update    	update the boot image ramdisk and header property
help		print the help information for the specificed actionn
See bootimg-tools help <action> for detailed informationn"


Unpack: unpacks a boot image into it's constituent parts
Usage:  	bootimg-tools unpack <boot image file> <switches>
Switches:
    -h, --header [filename]           Extract the boot image header and additional useful
                                      information to [filename] leave filename empty to use
                                      default filename ( default=header)
    -c, --cmdline [filename]          Extract the boot image kernel cmdline to [filename]
                                      leave filename empty to use default filename ( default=cmdline )
    -p, --pagesize [filename]         Extract the value of the boot image pagesize to [filename]
                                      leave filename empty to use default filename ( default=pagesize )
    -k, --kernel [filename]           Extract kernel image to [filename] leave filename
                                      empty to use default filename ( defualt=kernel )
    -d, --ramdisk-directory [dir]     Fully Extract the ramdisk to [dir] leave dir empty to use
                                      default directory ( default=root )
    -x, --ramdisk-archive [filename]  Extract the compressed ramdisk to [filename] leave filename
                                      empty to use default ( default=initramfs.cpio.<type> ), when
                                      using the defaults the <type> will be determined by the file magic
                                      common type are lzop (.lzo) and gzip (.gz)
Notes: <boot image file>  is required and must be a valid android boot image
       --kernel, --header, --cmdline and --pagesize are optional --header includes the cmdline and pagesize info
       --ramdisk-archive and --ramdisk-directory are optional
  All optional commands can be used in any combination required.
                                      

Unpack: creates a boot image from constituent parts
Usage:  	bootimg-tools pack <bootimage file> <switches>
Switches:
    -h, --header [filename]           Use cmdline and pagesize information contained in [filename]
                                      leave filename empty to use default filename ( default=header)
    -c, --cmdline <filename | text >  Use cmdline information contained in [filename] leave filename
                                      empty to use default filename ( default=cmdline ) or specify a
                                      cmdline text directly using text enclosed in single quotes ''
    -p, --pagesize <filename | text > Use pagesize information contained in [filename] leave filename
                                      empty to use default filename ( default=pagesize ) or specify a
                                      pagesize value directly using text
    -k, --kernel [filename]           Use kernel image in [filename] leave filename
                                      empty to use default filename ( defualt=kernel )
    -d, --ramdisk-directory [dir]     Use [dir] as the ramdisk root leave dir empty to use
                                      default directory ( default=root ) 
    -x, --ramdisk-archive [filename]  Use [filename] as compressed ramdisk leave filename
                                      empty to use default ( default=initramfs.cpio.gz )
Notes: <boot image file>  is required and must be a valid android boot image
       --kernel, --header, --cmdline and --pagesize are optional --header includes the cmdline and pagesize info
       --ramdisk-archive and --ramdisk-directory are require an exclusive to one another
  All optional commands can be used in any combination required.