Re: [linuxdc-dev] VMU driver (Better maple)

[Paul M. <pm...@mv...>]

On Sat, Jan 26, 2002 at 07:22:13PM -0600, M. R. Brown wrote:
> > Well, I might be reading the whole thing wrong, but as I understand
> > the code, it provides both char and block devices for each mtd device.
> > However, the mtd map handler has a byte-based interface which seems
> > like a lot of extra work to implement. This may however be incorrect.
> > I will do some more reading, but maybe someone more knowledge can save
> > me some trouble by pointing me in the right direction?
>=20
> I remember now.  Paul's idea was to read/write from the VMU in blocks, but
> provide the byte-interface for the currently held block.  If you need byte
> 512, you'd have to read in that block in order to get to it.  Sound sane?
>=20
Right. Maple is stupid. If we could have raw access to the device and just
map the whole region directly, it wouldn't be a problem.. the problem is th=
at
the only kind of access to the device that we have is in full blocks. If we
don't want to read in a whole block, we still need to do the math to find o=
ut
where the end of our read sits, read that block, and then deal with masking
off only that which we're interested in, and handing it all back.. it's not=
 a
very fun system, but the driver is documented and does outline all of this..
so it shouldn't be of much surprise to anyone.

Fucking useless maple.

Regards,

--=20
Paul Mundt <pm...@mv...>
MontaVista Software, Inc.