On Fri, 04 Sep 2009 12:57:57 +0200 Wolfgang Denk wd@denx.de wrote:
Dear Simon Kagstrom,
In message 20090904103602.7a0ec3fd@marrow.netinsight.se you wrote:
Understandable. On the other hand, it should be possible to pad the U-boot image to some specific size to keep the size constant. Typically to the erase size.
This makes no sense. Why would such padding be needed? It only adds overhead everywhere where the image needs to be processed, stored, downloaded, programmed, etc.
In this case to have keep the kirkwood boot header unchanged, and to just update the U-boot image.
Doesn't the header contain checksums and such? And what would that save you? Building the image with header is supposed to be a very cheap operation.
I believe the checksums are for the header and the header extension - the image itself contains a checksum in the last 4 bytes.
The idea was to avoid having to rewrite the same block all the time. Anyway, Prafulla has explained why it's difficult (or maybe impossible) to use this method, so I think we can safely drop this subject for now.
// Simon