General options¶

-h

--help

Print a help message and exit.

-l

--list

mkimage lists the information contained in the header of an existing U-Boot image.

-s

--no-copy

Don't copy in the image data. Depending on the image type, this may create just the header, everything but the image data, or nothing at all.

-T image-type

--type image-type

Parse image file as image-type. Pass list as image-type to see the list of supported image types. If this option is absent, then it defaults to kernel (legacy image). If this option is absent when -l is passed, then mkimage will attempt to automatically detect the image type. Not all image types support automatic detection, so it may be necessary to pass -T explicitly.

When creating a FIT image with -f, the image type is always set to flat_dt. In this case, -T specifies the image node's ‘type’ property. If -T is absent, then the ‘type’ property will default to kernel.

-q

--quiet

Quiet. Don't print the image header.

-v

--verbose

Verbose. Print file names as they are added to the image.

-V

--version

Print version information and exit.

General image-creation options¶

-A architecture

--architecture architecture

Set the architecture. Pass -h as the architecture to see the list of supported architectures. If -A is absent, it defaults to ppc.

-O os

--os os

Set the operating system. The U-Boot bootm command changes boot method based on the OS type. Pass -h as the os to see the list of supported OSs. If -O is absent, it defaults to linux.

-C compression-type

--compression compression-type

Set the compression type. The image data should have already been compressed using this compression type. mkimage will not automatically compress image data. Pass -h as the compression-type to see the list of supported compression types. If -C is absent, it defaults to gzip.

-a load-address

--load-address load-address

Set the absolute address to load the image data to. load-address will be interpreted as a hexadecimal number.

-e entry-point

--entry-point entry-point

Set the absolute address of the image entry point. The U-Boot bootm command will jump to this address after loading the image. entry-point will be interpreted as a hexadecimal number.

-n primary-configuration

--config primary-configuration

Images may require additional configuration not specified with other options, often in a image-type-specific format. The image types which support this option and the format of their configuration are listed in CONFIGURATION.

-R secondary-configuration

--secondary-config secondary-configuration

Some image types support a second set of configuration data. The image types which support secondary configuration and the formap of their configuration are listed in CONFIGURATION.

-d image-data-file

--image image-data-file

Use image data from image-data-file. If the image-type is multi, then multiple images may be specified, separated by colons:

-x

--xip

Set the XIP (execute in place) flag. The U-Boot bootm command will not load the image data, and instead will assume it is already accessible at the load address (such as via memory-mapped flash).

Options for creating FIT images¶

-b device-tree-file

--device-tree device-tree-file

Appends the device tree binary file (.dtb) to the FIT.

-c comment

--comment comment

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

-D dtc-options

--dtcopts dtc-options

Provide additional options to the device tree compiler when creating the image. See dtc(1) for documentation of possible options. If -D is absent, it defaults to -I dts -O dtb -p 500.

-E

--external

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.

-B alignment

--alignment alignment

The alignment, in hexadecimal, that external data will be aligned to. This option only has an effect when -E is specified.

-p external-position

--position external-position

Place external data at a static external position. 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. See -E for details on using external data.

-f image-tree-source-file | auto | auto-conf

--fit image-tree-source-file | auto | auto-conf

Image tree source file that describes the structure and contents of the FIT image.

In some simple cases, the image tree source can be generated automatically. To use this feature, pass -f auto. The -d, -A, -O, -T, -C, -a, and -e options may be used to specify the image to include in the FIT and its attributes. No image-tree-source-file is required. The -g, -o, and -k or -G options may be used to get ‘images’ signed subnodes in the generated auto FIT. Instead, to get ‘configurations’ signed subnodes and ‘images’ hashed subnodes, pass -f auto-conf. In this case -g, -o, and -k or -G are mandatory options.

-F

--update

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

-i ramdisk-file

--initramfs ramdisk-file

Append a ramdisk or initramfs file to the image.

-k key-directory

--key-dir 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. The public key is only necessary when embedding it into another device tree using -K. name is the value of the signature node's ‘key-name-hint’ property.

-G key-file

--key-file key-file

Specifies the private key file to use when signing. This option may be used instead of -k. Useful when the private key file basename does not match ‘key-name-hint’ value. But note that it may lead to unexpected results when used together with -K and/or -k options.

-K key-destination

--key-dest 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.

-g key-name-hint

--key-name-hint key-name-hint

Specifies the value of signature node ‘key-name-hint’ property for an automatically generated FIT image. It makes sense only when used with -f auto or -f auto-conf. This option also indicates that the images or configurations included in the FIT should be signed. If this option is specified, then -o must be specified as well.

-o checksum,crypto

--algo checksum,crypto

Specifies the algorithm to be used for signing a FIT image, overriding value taken from the signature node ‘algo’ property in the image-tree-source-file. It is mandatory for automatically generated FIT.

The valid values for checksum are:

The valid values for crypto are:

-r

--key-required

Specifies that keys used to sign the FIT are required. This means that images or configurations signatures must be verified before using them (i.e. to boot). Without this option, the verification will be optional (useful for testing but not for release). It makes sense only when used with -K. When both, images and configurations, are signed, ‘required’ property value will be "conf".

-N engine

--engine engine

The openssl engine to use when signing and verifying the image. For a complete list of available engines, refer to engine(1).

-t

--touch

Update the timestamp in the FIT.

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

aisimage¶

The primary configuration is a file containing a series of AIS (Application Image Script) commands, one per line. Each command has the form

See TI application report SPRAAG0E for details.

atmelimage¶

The primary configuration is a comma-separated list of NAND Flash parameters of the form

Valid parameters are

and valid values are decimal numbers. See section 11.4.4.1 of the SAMA5D3 Series Data Sheet for valid values for each parameter.

imximage¶

The primary configuration is a file containing configuration commands, as documented in doc/imx/mkimage/imximage.txt of the U-Boot source.

imx8image and imx8mimage¶

The primary configuration is a file containing configuration commands, as documented in doc/imx/mkimage/imx8image.txt of the U-Boot source.

kwbimage¶

The primary configuration is a file containing configuration commands, as documented in doc/imx/mkimage/kwbimage.txt of the U-Boot source.

mtk_image¶

The primary configuration is a semicolon-separated list of header options of the form

where the valid keys are:

Valid values for media are:

Valid values for nandinfo are:

mxsimage¶

The primary configuration is a file containing configuration commands, as documented in doc/imx/mkimage/mxsimage.txt of the U-Boot source.

omapimage¶

The primary configuration is the optional value byteswap. If present, each 32-bit word of the image will have its bytes swapped (converting from little-endian to big-endian, or vice versa).

pblimage¶

The primary configuration is a file containing the PBI (Pre-Boot Image) header. Each line of the configuration has the format

Where value is a 32-bit hexadecimal integer. Each value will, after being converted to raw bytes, be literally prepended to the PBI.

The secondary configuration is a file with the same format as the primary configuration file. It will be inserted into the image after the primary configuration data and before the image data.

It is traditional to use the primary configuration file for the RCW (Reset Configuration Word), and the secondary configuration file for any additional PBI commands. However, it is also possible to convert an existing PBI to the above format and “chain” additional data onto the end of the image. This may be especially useful for creating secure boot images.

rkimage¶

The primary configuration is the name of the processor to generate the image for. Valid values are:

spkgimage¶

The primary configuration file consists of lines containing key/value pairs delimited by whitespace. An example follows.

# Comments and blank lines may be used
key1 value1
key2 value2

The supported key types are as follows.

VERSION

NAND_ECC_BLOCK_SIZE

NAND_ECC_ENABLE

NAND_ECC_SCHEME

NAND_BYTES_PER_ECC_BLOCK

These all take a positive integer value as their argument. The value will be copied directly into the respective field of the SPKG header structure. For details on these values, refer to Section 7.4 of the Renesas RZ/N1 User's Manual.

ADD_DUMMY_BLP

Takes a numeric argument, which is treated as a boolean. Any nonzero value will cause a fake BLp security header to be included in the SPKG output.

PADDING

Takes a positive integer value, with an optional K or M suffix, indicating KiB / MiB respectively. The output SPKG file will be padded to a multiple of this value.

sunxi_egon¶

The primary configuration is the name to use for the device tree.

ublimage¶

The primary configuration is a file containing configuration commands, as documented in doc/README.ublimage of the U-Boot source.

zynqimage and zynqmpimage¶

For zynqmpimage, the primary configuration is a file containing the PMUFW (Power Management Unit Firmware). zynqimage does not use the primary configuration.

For both image types, the secondary configuration is a file containinig initialization parameters, one per line. Each parameter has the form

where address and data are hexadecimal integers. The boot ROM will write each data to address when loading the image. At most 256 parameters may be specified in this manner.