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 address]
              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:

       -b [device tree file]
              Appends the device tree binary file (.dtb) to the FIT.

       -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.

       -E     After processing, move the image data outside the FIT and store a data offset in the  FIT.  Images
              will  be  placed  one after the other immediately after the FIT, with each one aligned to a 4-byte
              boundary. The existing 'data' property in each image  will  be  replaced  with  'data-offset'  and
              'data-size'  properties.   A  'data-offset'  of  0  indicates  that it starts in the first (4-byte
              aligned) byte after the FIT.

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

              This can be automatically generated for some simple cases.  Use "-f auto" for this. In  that  case
              the  arguments  -d,  -A, -O, -T, -C, -a and -e are used to specify the image to include in the FIT
              and its attributes.  No .its file is required.

       -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.

       -i [ramdisk_file]
              Appends the ramdisk file to the FIT.

       -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.

       -p [external position]
              Place external data at a static external position. See -E.  Instead  of  writing  a  'data-offset'
              property  defining the offset from the end of the FIT, -p will use 'data-position' as the absolute
              position from the base of the FIT.

       -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).

       -t     Update the timestamp in the FIT.

              Normally the FIT timestamp is created the first time mkimage is run on a FIT, when converting  the
              source  .its  to  the binary .fit file. This corresponds to using the -f flag. But if the original
              input to mkimage is a binary file (already compiled) then the timestamp is assumed  to  have  been
              set previously.

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

       Create a FIT image containing a kernel, using automatic mode. No .its file is required.
       mkimage -f auto -A arm -O linux -T kernel -C none -a 43e00000 -e 0 \
       -c "Kernel 4.4 image for production devices" -d vmlinuz kernel.itb

       Create  a FIT image containing a kernel and some device tree files, using automatic mode. No .its file is
       required.
       mkimage -f auto -A arm -O linux -T kernel -C none -a 43e00000 -e 0 \
       -c "Kernel 4.4 image for production devices" -d vmlinuz \
       -b /path/to/rk3288-firefly.dtb -b /path/to/rk3288-jerry.dtb 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)