[U-Boot] Questions on adding a new type to mkimage

[Charles Manning]

I am in the throes of extending mkimage to add socfpga support. This is my 
first time in mkimage, so please forgive me being on a learning curve.

It seems that the most "normal" path for mkimage signers is to append some 
sort of header to the front of the image
ie the flow is

write header out
copy image data with copy_file
call set_header

The socfpga preloader needs something a bit different. It does not add a 
header, but instead adds a tail (CRC+padding) and mashes some bytes into a 
known place in the image.

Unfortunately the mkimage framework does not seem to provide an "add tail" 
function which is really what is needed here.

The only way I can see to extend the size of the image, using the normal 
mkimage workflow would be to do something like this:

*Provide vrec_header which adds a fake header of 64k - input_size.
* Allow copy_file to then do the copy step.
* I now have a 64k "image" which is 64k-size 0 bytes, followed by the actual 
input_data.
* When set_header is called, shift the actual input data to where it should 
be, add the CRC and fix up the padding.

This seems needlessly contrived to work with the framework.

Or the alternative might be just to treat this as a special case....

Thoughts/opinions???

Thanks

Charles