14.2.18. How can I load and uncompress a compressed image

Question:

I want to use U-Boot to load a compressed filesystem image from flash into RAM, and to uncompress it. Is this possible?

Answer:

Yes, this is possible. You should generate your image as type "standalone" image (using "mkimage ... -T standalone ...") and then set the environment variable "autostart" to "no" ("setenv autostart no"). If you then use the "bootm" command for such an image, U-Boot will uncompress the code and store it at the "load address" ("-a" option for mkimage), but not attempt to start it yet.

If you want to start it directly, just omit the setting of "autostart", and U-Boot will automagically start the image by jumping to the entry point address ("-e" option for mkimage).