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Some thoughts about the flash device driver and the flashdisk block driver
- Date: Fri, 25 Jan 2008 10:28:22 +1100
- From: chrisj at rtems.org (Chris Johns)
- Subject: Some thoughts about the flash device driver and the flashdisk block driver
Ian Caddy wrote:
> One thing to be aware of is that most NOR type flash chips do not allow
> you to read from them while writing to them. This would mean that you
> can't run RTEMS from the flash while programming another area of the
> same flash chip.
Yes this is a good point.
> There are normally two solutions to this problem, copy everything into
> RAM and run from there, allowing full access to the flash, or have a
> separate flash chip for your file system.
The other solution is to have RAM based handlers for the flash and disable
interrupts during the writing. I consider this a last resort type function and
very specific system in use. Disabling interrupts for this period of time is