[U-Boot-Users] [PATCH] jffs2 indirect access.

Kenneth Johansson kenneth.johansson at etx.ericsson.se
Thu Jul 24 14:35:05 CEST 2003


This is a patch that alters the jffs2 code to work on flash devices that
is not directly memory mapped without the need to copy the whole flash
to RAM.

It is not ready for inclusion and I do not think I will push it as it
was quite a bit slower than I expected. It also needs a little more
cleanup.

A callback function is added to struct part_info that works like memcpy
and is the thing actually reading the flash. The offset member is gone
and the jffs2 code always uses 0 as the start address for the
filesystem. It is up to the callback function to remap that into
something useful.

This code however uses less memory than copying the flash to ram but it
is slower. jffs2_scan_empty() could use some speedup but even in
situations when that one is not taking mush time this is slower by a
factor of 2-3. It's only faster if you happens to have ridiculously slow
flash.

I'm going on vacation and is not going to work more on this so if
someone wants this added to u-boot you have to fix a proper patch
yourself. 


-- 
Kenneth Johansson	
Ericsson AB                       Tel: +46 8 719 70 20
Tellusborgsvägen  90              Fax: +46 8 719 29 45
126 25 Stockholm                  ken at switchboard.ericsson.se
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