Some thoughts about the flash device driver and the flashdisk block driver

[chrisj at rtems.org (Chris Johns)]

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 
not nice.

Regards
Chris