infradead.org vs kernel.org sources

infradead.org vs kernel.org sources

[Kent Borg]

Hello, a newbie here, and I thought I was making good progress
(debugging why I couldn't talk to our flash at all), and then I got
confused over sources.

I am working on an embedded PPC 405 controller.  We started with 2.4.2
sources from mvista.com, which seem quite close to kernel.org.  And
the main MTD web page <http://www.linux-mtd.infradead.org/> says "Very
occasionally, I make snapshot releases. Now that the MTD code is in
the 2.4 kernel, it's become even rarer. ", which I took to mean that
the kernel.org sources were up to date.

But now I had occasion to look at the stuff I grabbed from the
infradead cvs repository.  It looks rather different.

For example, mtd/drivers/mtd in the infradead sources seems to have
files I find in linux/drivers/mtd in kernel.org sources, but the
infradead sources are more elaborate and have sub-directories.

I guess my next move is to drop that infradead sub-tree into the
linux/drivers/mtd directory and see what happens.  (I think we need to
directly link, not be a loadable module, so the sources need to be
merged.)

Is this what I want?


Thanks,

-kb, the Kent who hopes to get JFFS working on top of MTD.

Building MTD with JFFS2

[Kent Borg]

On Tue, Jul 31, 2001 at 05:54:42PM -0400, I wrote:
> Hello, a newbie here, and I thought I was making good progress
> (debugging why I couldn't talk to our flash at all), and then I got
> confused over sources.

And now I am getting closer.

Following e-mailed advice of Abraham vd Merwe <abraham@2d3d.co.za> I
used the infradead.org sources.  He sent me a script that copied the
right cvs-ed files into the right places in the regular 2.4 kernel
tree, but that left me with no configuration mention of JFFS2 and a
compile error in the old JFFS directory.

Resorting to a little RTFM I looked at the mtd-jffs-HOWTO and followed
its approach ("sh patchin.sh /usr/src/linux"), and got the same
results: no mention of JFFS2 in the configuring and the same compile
error in linux/fs/jffs (inode-v23.c, line 93, no member named
s_maxbytes).

Looking at the mtd/patches/Configure.help I see mention of
CONFIG_JFFS2_FS and CONFIG_JFFS2_FS_DEBUG, I tried manually defining
them in autoconf.h as 1 and 3 respectively, and in linux/fs/Makefile I
changed the instances of jffs and JFFS to jffs2 and JFFS2 respectively.

This made my compile happy, but, though the make dep seems to have
visited the linux/fs/jffs directory, the make itself didn't.

Hmmm.  Ideas on how to get out of the newbie mud?


In the mean time, because we don't have CFI chips, I think I will look
into whether I need to write my own mtd driver.  (AMD and Intel chips,
but old ones.)


Thanks,

-kb, the Kent who is glad there are those who have been here before
him.

Re: Building MTD with JFFS2

[David Woodhouse]

kentborg@borg.org said:
>  This made my compile happy, but, though the make dep seems to have
> visited the linux/fs/jffs directory, the make itself didn't.

> Hmmm.  Ideas on how to get out of the newbie mud? 

Look at the 2.4-ac patches. They have all the necessary glue you need to 
add the fs/jffs2 directory to the build.


kentborg@borg.org said:
>  In the mean time, because we don't have CFI chips, I think I will
> look into whether I need to write my own mtd driver.  (AMD and Intel
> chips, but old ones.) 

We have drivers for them, but just can't necessarily recognise them. Rather 
than doing a whole new driver, you need to just write a probe routine which 
passes control to the cfi_cmdset_000x drivers like cfi_probe.c does.

The actual commands are the same - CFI only defines how you probe the chips
to identify them.

--
dwmw2