DUMPIMAGE(1) General Commands Manual DUMPIMAGE(1)

dumpimage - extract data from U-Boot images

dumpimage [-T type] -l image
dumpimage [-T type] [-p position] -o outfile image
dumpimage -h
dumpimage -V

dumpimage lists and extracts data from U-Boot images. If -l is specified, dumpimage lists the components in image. Otherwise, dumpimage extracts the component at position to outfile.

Print usage information and exit.
Print the header information for image, including a list of components.
The file to write the dumped component to.
Specify the position of the component to dump. This should be a numeric index, starting at 0. If not specified, the default position is 0.
Specify the type of the image. If not specified, the image type will be automatically detected. A list of supported image types may be printed by running mkimage -T list.
Print version information and exit.

Please report bugs to the U-Boot bug tracker.

Create a multi-file image and then extract part of that image

$ 
mkimage -A x86 -O linux -T multi -n x86 \
-d vmlinuz:initrd.img:System.map multi.img
Image Name:   x86
Created:      Thu Jul 25 10:29:13 2013
Image Type:   Intel x86 Linux Multi-File Image (gzip compressed)
Data Size:    13722956 Bytes = 13401.32 kB = 13.09 MB
Load Address: 00000000
Entry Point:  00000000
Contents:
   Image 0: 4040128 Bytes = 3945.44 kB = 3.85 MB
   Image 1: 7991719 Bytes = 7804.41 kB = 7.62 MB
   Image 2: 1691092 Bytes = 1651.46 kB = 1.61 MB
$ 
dumpimage -p 2 -o System.map multi.img

mkimage(1)

2022-06-11 U-Boot