From: D. Jeff Dionne (jeff@rt-control.com)
Date: Fri Jul 07 2000 - 19:09:28 EDT
Joe deBlaquiere <joe@wirespeed.com> said: > I'm using blkmem.c to allow me to access and rewrite the flash memory. It > generally works very cleanly except that I couldn't figure out a nice way to > define a memory block device to be sectored heterogeneously. I'm using an blkmem, although it has some limited write capibility, is not good at this sort of thing. Kenneth added the original FLASH write code for our SHGL platform in mid 1998, and it's an ugly hack (although a useful one), This stuff will go away in favor of the JFFS code contributed by Axis for r/w FLASH. > AMD flash that has a mixture of 8k and 64k blocks. As a workaround, I FLASH may have arbitrary block sizes in the general case, of course. You'll need a sector map to do it right, and you'll have to read the device ID codes. Problem is, you can't do that an execute out of the device at the same time (which is why the switch has not yet been competed to JFFS). > defined two block devices with the same origin. one has small blocks and one > has big ones. This was good'nuff to get what I needed, but now I'm thinking > about doing it right. > > Am I missing something or is the current driver only for equal-sectored > (monolithic, right?) devices? blkmem.c is Kenneth's expanded version of my kmem.c to include a hack to allow one to update the underlying FLASH memory (for config and upgrade). Greg has also done a bunch of work on it. It really has no design goals beyond supporting (for write) that which was on the hardware at hand. > > Has anybody done this already, or should I start? > look at flash.c in 2.0.38.1pre7 Jeff > Are there any other features I should be thinking about adding while I'm > under the hood? lock/unlock sectors? > > Joe deBlaquiere > WireSpeed Communications > 307 Wynn Drive > Huntsville, AL 35805 > voice : 256-704-9257 > fax : 256-837-3839 > > This message resent by the uclinux-dev@uclinux.org list server http://www.uClinux.org/ > This message resent by the uclinux-dev@uclinux.org list server http://www.uClinux.org/
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