Re: How to save a file into a iPaq and get its back?

On Tuesday 19 December 2000 09:54, Jari Kirma wrote:
> Shane NAy wrote:
> : 512 byte eraseblocks on flash is like..., non-existant :-). That's
> : actually one of the majory problems with r/w flash. Eraseblocks of
> : flash are more in the realm of 64 or 128kbit. (Agenda's use 128kbit
> : eraseblocks)
>
> (Bits or bytes?)
>
> Ah, checked some specs of block-mapped (NAND) flashes from Samsung. Writes
> had to be made with disk-like 528 byte blocks, but erases were 16k - I'm
> happy we don't use this kind of flash, even jffs would make large amounts
> of page erases when doing only small changes...

I say "kbit", because I mean kbit :-), not byte. 128 kilo-bit flash units
(Intel's strataflash)

>
> Personally I've used ext2 on flash for now - but with extreme suspicion.
> How many flash erases I generate with single chmod? At least one. How many
> with small change to shell script? Several I guess. And those updates are
> concentrated on certain pages, probably. Thus I use flash only to store
> what must be stored on flash.
>

Just get mtdblock working and your problems will be gone. It's not all that
difficult. Just mod nora.c's layout to match the flash layout on the device
you are using, and as long as you're not using a XIP mode kernel, it will
just be a compile away from working. (If you are using a XIP mode kernel,
grab patches from ftp.agendacomputing.com)

Thanks,
Shane.
Received on Tue Dec 19 02:00:27 2000