Dear Wolfgang,
On 30.07.2018 13:45, Wolfgang Denk wrote:
Dear Simon,
In message 20180730105319.79424-2-sgoldschmidt@de.pepperl-fuchs.com you wrote:
To prepare supporting compression for all image types, change compression to "none" for ramdisks in all examples.
What makes you think this is a correct thing to do?
There are different approaches to handle things. For example, traditionally on Power Architecture we would use a raw kernel binray, compress this (for example with gzip) before wrapping it with mkimage into an (uImage or FIT) U-Boot image, and then let U-Boot uncompress the kernel image into rum and start it. On ARM the kernel comes traditionally with it's own wrapper that does unompressions and such.
Same for ramdisk handling. On some systems it may make sense to have U-Boot handle the uncompressing, so compression = "gzip"; may be fully intentional.
That's the whole point and in the thread I mentioned (https://lists.denx.de/pipermail/u-boot/2018-July/336435.html) it has been discussed that this is the future goal.
However, uncompression currently is only implemented for kernels, not for other sub-images. This patch aims at updating the docs and the current .its examples to what they do now.
Best regards, Simon