[En-Nut-Discussion] Example using UFLASH filesystem

[Bernd Walter]

On Sun, Oct 31, 2010 at 10:30:37AM +0100, Bernd Walter wrote:
> On Thu, Oct 28, 2010 at 10:18:15AM +0200, Ole Reinhardt wrote:
> > Hi!
> > 
> > I just saw ulrich reposted my example for UFLASHFS registering. If you
> > need some more help, just let me know.
> 
> While reading the source I've noticed that vol->vol_ifc->sf_rsvbot
> is added at several places.
> Given the variablenames I would assume vol->vol_ifc->sf_rsvtop should
> be used instead.
> 
> What is the purspose of UFLASH_MAX_BLOCKS?
> I see that it is used to limit the device, but beside of switching
> some varibale sizes and limiting the device I don't see any usecase.
> For example the source has a default of 8192, which will make some
> variables 16 bit instead of 8 or 32 bit, but why limit to 8192, when
> 65535 would have the same effect?

Ok - I see all the for-loops, so a small number of blocks seems to be
good for performance.

> UFLASH_BLOCK_UNITS 4 means that on a 264Bytes/Block device a block
> will be 1056 Bytes and on a 1056 device it will be 4224 Bytes.
> What is the sense of using a fixed factor?
> What is the minimum/advised blocksize and number of blocks?
> E.g. can a 24LC16 (driver surgery assumed) with IIRC 128x 16Byte Blocks
> be used?

-- 
B.Walter <bernd at bwct.de> http://www.bwct.de
Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.