squashfs -- see squashfs pkg
loglevel -- for Puppy quiet bootup
dpath   -- maybe, for dazuko
ksize   -- maybe, for aufs 

aufs -- it looks like the latest driver is supplied as a kernel patch.

HOWTO apply the patches
-----------------------

Note: always use '--dry-run' first for patch, to make sure it works.

1. Loglevel
-----------

I edited kernel/printk.c:

/* We show everything that is MORE important than this.. */
#define MINIMUM_CONSOLE_LOGLEVEL 1 /* Minimum loglevel we let people use */
/* BK change from 7 to 3...
#define DEFAULT_CONSOLE_LOGLEVEL 7 */ /* anything MORE serious than KERN_DEBUG */
#define DEFAULT_CONSOLE_LOGLEVEL 3

2. Squashfs
-----------

For Puppy prior to 2.17:
# ln -s linux-2.6.21.1 /usr/src/linux-2.6.20
# cd /usr/src/linux-2.6.21.1
# patch -p1 < ../squashfs3.2-patch

For 2.6.21.5 kernel, Puppy 2.17:

Arrange so have dirs 'lzma443', 'squashfs3.2-r2' in current dir, and have have expanded
sqlzma3.2-r2b.tar.bz2 in current dir.
Expanded lzma443.tar.bz2 inside directory lzma443.
Got 'sqlzma1-443.patch' to lzma443 directory:
# patch -p0 < ./sqlzma1-443.patch
Now apply the normal squashfs patch to the kernel...
# cd /usr/src/linux-2.6.21.5
# patch -p1 < ../squashfs3.2-patch
and then also apply sqlzma2k-YYY.patch to kernel source:
# patch -p1 < ../sqlzma2k-3.2-r2.patch
Now change-dir to wherever the squashfs source has been expanded:
# cd <path>/squashfs3.2-r2
# patch -p1 < ../sqlzma2u-3.2-r2.patch
...this patches the squashfs tools.
the expanded 'sqlzma3.2-r2b' has Makefile, sqlzma.h, sqmagic.h in current dir,
which will build modules and utilities -- it is required to have
CONFIG_SQUASHFS*=n in kernel config, as modules are compiled separately here.
-- DO THIS LATER.

...okay ...this is complicated... I had to copy /usr/src/2.6.21.5/fs/squashfs to
<current dir>/squashfs3.2-r2/kernel-patches/linux-2.6.21.1/fs/squashfs
# make
...creates squashfs.ko, unlzma.ko and sqlzma.ko
...i copied these to /lib/modules/2.6.21.5/kernel/fs/squashfs/

curses, this last link line in squashfs-tools has undefined referencs:
cc   mksquashfs.o read_fs.o sort.o  -lz -L/usr/src/kernel-stuff-2.6.21.1/filesystems/squahfs-lzma-stuff/lzma443/C/7zip/Compress/LZMA_Alone -L/usr/src/kernel-stuff-2.6.21.1/filesystems/squahfs-lzma-stuff/lzma443/C/7zip/Compress/LZMA_C -lpthread -lunlzma_r -llzma_r -lstdc++ -o mksquashfs
... libunlzma_r.a has the missing refs. I stuck this on the end:  /usr/lib/libz.a

Ditto:
cc   unsquashfs.o  -lz -L/usr/src/kernel-stuff-2.6.21.1/filesystems/squahfs-lzma-stuff/lzma443/C/7zip/Compress/LZMA_Alone -L/usr/src/kernel-stuff-2.6.21.1/filesystems/squahfs-lzma-stuff/lzma443/C/7zip/Compress/LZMA_C -lunlzma -o unsquashfs



3. dpath patch, required by Dazuko
----------------------------------

# patch /lib/modules/2.6.21.1/build/fs/dcache.c patch_dpath.diff

Or, if already inside linux-2.6.21.1 directory:
# patch ./fs/dcache.c ../patch_dpath.diff

4. ksize patch, required by Aufs
--------------------------------

# cd /usr/src/linux-2.6.21.1
# patch -p0 < ../ksize.patch

5. Aufs patch ***NO, DO NOT NEED, COMPILED SEPARATELY***
-------------

6. Unionfs patch
----------------

# cd /usr/src/linux-2.6.21.1
# patch -p1 < ../linux-2.6.21-unionfs2.diff

-------------------------------------------------------------------------------

5 Aug 2007
----------
Recompile kernel with latest unionfs patch. keeping config exactly as before.
Have not done the loglevel patch.

# patch -p1 < ../squashfs3.2-patch
# patch -p1 < ../sqlzma2k-3.2-r2.patch
# patch -p0 < ../ksize.patch
# patch -p1 < ../linux-2.6.21.6-u4.diff

-------------------------------------------------------------------------------

8 Sept 2007
-----------

Now using 2.6.21.7 kernel.

1. applied loglevel patch.
2. no longer using lzma for squashfs, so jut do this:
   # patch -p1 < ../squashfs3.2-patch
3. # patch -p0 < ../ksize.patch
4. # patch ./fs/dcache.c ../patch_dpath.diff
5. # patch -p1 < ../unionfs-2.1.2_for_2.6.21.7.diff