NAME

       mkimage - Generate image for U-Boot

SYNOPSIS

       mkimage -l [uimage file name]

       mkimage [options] -f [image tree source file] [uimage file name]

       mkimage [options] -F [uimage file name]

       mkimage [options] (legacy mode)

DESCRIPTION

       The  mkimage  command is used to create images for use with the U-Boot boot loader.  These
       images can contain the linux kernel, device tree blob, root file  system  image,  firmware
       images etc., either separate or combined.

       mkimage supports two different formats:

       The  old legacy image format concatenates the individual parts (for example, kernel image,
       device tree blob and ramdisk image) and adds a  64  bytes  header  containing  information
       about target architecture, operating system, image type, compression method, entry points,
       time stamp, checksums, etc.

       The new FIT (Flattened Image Tree) format allows for more flexibility in  handling  images
       of various types and also enhances integrity protection of images with stronger checksums.
       It also supports verified boot.

OPTIONS

       List image information:

       -l [uimage file name]
              mkimage lists the information contained in the header of an existing U-Boot image.

       Create old legacy image:

       -A [architecture]
              Set architecture. Pass -h  as  the  architecture  to  see  the  list  of  supported
              architectures.

       -O [os]
              Set operating system. bootm command of u-boot changes boot method by os type.  Pass
              -h as the OS to see the list of supported OS.

       -T [image type]
              Set image type.  Pass -h as the image to see the list of supported image type.

       -C [compression type]
              Set compression type.  Pass -h as the compression to  see  the  list  of  supported
              compression type.

       -a [load addess]
              Set load address with a hex number.

       -e [entry point]
              Set entry point with a hex number.

       -l     List the contents of an image.

       -n [image name]
              Set image name to 'image name'.

       -d [image data file]
              Use image data from 'image data file'.

       -x     Set XIP (execute in place) flag.

       Create FIT image:

       -c [comment]
              Specifies  a  comment  to be added when signing. This is typically a useful message
              which describes how the image was signed or some other useful information.

       -D [dtc options]
              Provide special options to the device tree compiler that  is  used  to  create  the
              image.

       -f [image tree source file]
              Image tree source file that describes the structure and contents of the FIT image.

       -F     Indicates  that  an  existing  FIT  image should be modified. No dtc compilation is
              performed and the -f flag should not be given.  This can be  used  to  sign  images
              with additional keys after initial image creation.

       -k [key_directory]
              Specifies  the  directory containing keys to use for signing. This directory should
              contain a private key file <name>.key  for  use  with  signing  and  a  certificate
              <name>.crt (containing the public key) for use with verification.

       -K [key_destination]
              Specifies  a  compiled device tree binary file (typically .dtb) to write public key
              information into. When a private key is used to sign an  image,  the  corresponding
              public  key  is written into this file for for run-time verification. Typically the
              file here is the device tree binary used by CONFIG_OF_CONTROL in U-Boot.

       -r     Specifies that keys used to sign the FIT are required. This means that they must be
              verified  for  the  image  to  boot.  Without this option, the verification will be
              optional (useful for testing but not for release).

EXAMPLES

       List image information:
       mkimage -l uImage

       Create legacy image with compressed PowerPC Linux kernel:
       mkimage -A powerpc -O linux -T kernel -C gzip \
       -a 0 -e 0 -n Linux -d vmlinux.gz uImage

       Create FIT image with compressed PowerPC Linux kernel:
       mkimage -f kernel.its kernel.itb

       Create FIT image with compressed kernel and sign it with keys in the  /public/signing-keys
       directory.  Add  corresponding  public keys into u-boot.dtb, skipping those for which keys
       cannot be found. Also add a comment.
       mkimage -f kernel.its -k /public/signing-keys -K u-boot.dtb \
       -c Kernel 3.8 image for production devices kernel.itb

       Update an existing FIT image, signing it with additional keys.  Add  corresponding  public
       keys  into u-boot.dtb. This will resign all images with keys that are available in the new
       directory. Images that request signing with unavailable keys are skipped.
       mkimage -F -k /secret/signing-keys -K u-boot.dtb \
       -c Kernel 3.8 image for production devices kernel.itb

HOMEPAGE

       http://www.denx.de/wiki/U-Boot/WebHome

AUTHOR

       This manual page was written by Nobuhiro Iwamatsu <iwamatsu@nigauri.org> and Wolfgang Denk
       <wd@denx.de>. It was updated for image signing by Simon Glass <sjg@chromium.org>.

                                            2010-05-16                                 MKIMAGE(1)