1.TH MKIMAGE 1 "2010-05-16" 2 3.SH NAME 4mkimage \- Generate image for U-Boot 5.SH SYNOPSIS 6.B mkimage 7.RB "\-l [" "uimage file name" "]" 8 9.B mkimage 10.RB [\fIoptions\fP] " \-f [" "image tree source file" "]" " [" "uimage file name" "]" 11 12.B mkimage 13.RB [\fIoptions\fP] " \-F [" "uimage file name" "]" 14 15.B mkimage 16.RB [\fIoptions\fP] " (legacy mode)" 17 18.SH "DESCRIPTION" 19The 20.B mkimage 21command is used to create images for use with the U-Boot boot loader. 22These images can contain the linux kernel, device tree blob, root file 23system image, firmware images etc., either separate or combined. 24 25.B mkimage 26supports two different formats: 27 28The old 29.I legacy image 30format concatenates the individual parts (for example, kernel image, 31device tree blob and ramdisk image) and adds a 64 bytes header 32containing information about target architecture, operating system, 33image type, compression method, entry points, time stamp, checksums, 34etc. 35 36The new 37.I FIT (Flattened Image Tree) format 38allows for more flexibility in handling images of various types and also 39enhances integrity protection of images with stronger checksums. It also 40supports verified boot. 41 42.SH "OPTIONS" 43 44.B List image information: 45 46.TP 47.BI "\-l [" "uimage file name" "]" 48mkimage lists the information contained in the header of an existing U-Boot image. 49 50.P 51.B Create old legacy image: 52 53.TP 54.BI "\-A [" "architecture" "]" 55Set architecture. Pass \-h as the architecture to see the list of supported architectures. 56 57.TP 58.BI "\-O [" "os" "]" 59Set operating system. bootm command of u-boot changes boot method by os type. 60Pass \-h as the OS to see the list of supported OS. 61 62.TP 63.BI "\-T [" "image type" "]" 64Set image type. 65Pass \-h as the image to see the list of supported image type. 66 67.TP 68.BI "\-C [" "compression type" "]" 69Set compression type. 70Pass \-h as the compression to see the list of supported compression type. 71 72.TP 73.BI "\-a [" "load address" "]" 74Set load address with a hex number. 75 76.TP 77.BI "\-e [" "entry point" "]" 78Set entry point with a hex number. 79 80.TP 81.BI "\-l" 82List the contents of an image. 83 84.TP 85.BI "\-n [" "image name" "]" 86Set image name to 'image name'. 87 88.TP 89.BI "\-d [" "image data file" "]" 90Use image data from 'image data file'. 91 92.TP 93.BI "\-x" 94Set XIP (execute in place) flag. 95 96.P 97.B Create FIT image: 98 99.TP 100.BI "\-b [" "device tree file" "] 101Appends the device tree binary file (.dtb) to the FIT. 102 103.TP 104.BI "\-c [" "comment" "]" 105Specifies a comment to be added when signing. This is typically a useful 106message which describes how the image was signed or some other useful 107information. 108 109.TP 110.BI "\-D [" "dtc options" "]" 111Provide special options to the device tree compiler that is used to 112create the image. 113 114.TP 115.BI "\-E 116After processing, move the image data outside the FIT and store a data offset 117in the FIT. Images will be placed one after the other immediately after the 118FIT, with each one aligned to a 4-byte boundary. The existing 'data' property 119in each image will be replaced with 'data-offset' and 'data-size' properties. 120A 'data-offset' of 0 indicates that it starts in the first (4-byte aligned) 121byte after the FIT. 122 123.TP 124.BI "\-f [" "image tree source file" " | " "auto" "]" 125Image tree source file that describes the structure and contents of the 126FIT image. 127 128This can be automatically generated for some simple cases. 129Use "-f auto" for this. In that case the arguments -d, -A, -O, -T, -C, -a 130and -e are used to specify the image to include in the FIT and its attributes. 131No .its file is required. 132 133.TP 134.BI "\-F" 135Indicates that an existing FIT image should be modified. No dtc 136compilation is performed and the \-f flag should not be given. 137This can be used to sign images with additional keys after initial image 138creation. 139 140.TP 141.BI "\-i [" "ramdisk_file" "]" 142Appends the ramdisk file to the FIT. 143 144.TP 145.BI "\-k [" "key_directory" "]" 146Specifies the directory containing keys to use for signing. This directory 147should contain a private key file <name>.key for use with signing and a 148certificate <name>.crt (containing the public key) for use with verification. 149 150.TP 151.BI "\-K [" "key_destination" "]" 152Specifies a compiled device tree binary file (typically .dtb) to write 153public key information into. When a private key is used to sign an image, 154the corresponding public key is written into this file for for run-time 155verification. Typically the file here is the device tree binary used by 156CONFIG_OF_CONTROL in U-Boot. 157 158.TP 159.BI "\-p [" "external position" "]" 160Place external data at a static external position. See \-E. Instead of writing 161a 'data-offset' property defining the offset from the end of the FIT, \-p will 162use 'data-position' as the absolute position from the base of the FIT. 163 164.TP 165.BI "\-r 166Specifies that keys used to sign the FIT are required. This means that they 167must be verified for the image to boot. Without this option, the verification 168will be optional (useful for testing but not for release). 169 170.TP 171.BI "\-t 172Update the timestamp in the FIT. 173 174Normally the FIT timestamp is created the first time mkimage is run on a FIT, 175when converting the source .its to the binary .fit file. This corresponds to 176using the -f flag. But if the original input to mkimage is a binary file 177(already compiled) then the timestamp is assumed to have been set previously. 178 179.SH EXAMPLES 180 181List image information: 182.nf 183.B mkimage -l uImage 184.fi 185.P 186Create legacy image with compressed PowerPC Linux kernel: 187.nf 188.B mkimage -A powerpc -O linux -T kernel -C gzip \\\\ 189.br 190.B -a 0 -e 0 -n Linux -d vmlinux.gz uImage 191.fi 192.P 193Create FIT image with compressed PowerPC Linux kernel: 194.nf 195.B mkimage -f kernel.its kernel.itb 196.fi 197.P 198Create FIT image with compressed kernel and sign it with keys in the 199/public/signing-keys directory. Add corresponding public keys into u-boot.dtb, 200skipping those for which keys cannot be found. Also add a comment. 201.nf 202.B mkimage -f kernel.its -k /public/signing-keys -K u-boot.dtb \\\\ 203.br 204.B -c """Kernel 3.8 image for production devices""" kernel.itb 205.fi 206 207.P 208Update an existing FIT image, signing it with additional keys. 209Add corresponding public keys into u-boot.dtb. This will resign all images 210with keys that are available in the new directory. Images that request signing 211with unavailable keys are skipped. 212.nf 213.B mkimage -F -k /secret/signing-keys -K u-boot.dtb \\\\ 214.br 215.B -c """Kernel 3.8 image for production devices""" kernel.itb 216.fi 217 218.P 219Create a FIT image containing a kernel, using automatic mode. No .its file 220is required. 221.nf 222.B mkimage -f auto -A arm -O linux -T kernel -C none -a 43e00000 -e 0 \\\\ 223.br 224.B -c """Kernel 4.4 image for production devices""" -d vmlinuz kernel.itb 225.fi 226.P 227Create a FIT image containing a kernel and some device tree files, using 228automatic mode. No .its file is required. 229.nf 230.B mkimage -f auto -A arm -O linux -T kernel -C none -a 43e00000 -e 0 \\\\ 231.br 232.B -c """Kernel 4.4 image for production devices""" -d vmlinuz \\\\ 233.B -b /path/to/rk3288-firefly.dtb -b /path/to/rk3288-jerry.dtb kernel.itb 234.fi 235 236.SH HOMEPAGE 237http://www.denx.de/wiki/U-Boot/WebHome 238.PP 239.SH AUTHOR 240This manual page was written by Nobuhiro Iwamatsu <iwamatsu@nigauri.org> 241and Wolfgang Denk <wd@denx.de>. It was updated for image signing by 242Simon Glass <sjg@chromium.org>. 243