[OT] Kernel extentions

[Love]

Dima Brodsky <dima at cs.ubc.ca> writes:

> Hi,
>
> I am trying to build a kernel extention that contains a VFS
> layer.  I am using arla as an example and using a nullfs example
> that has been put into a kernel extention in project builder.

You might want to look at a newer version (pre-releases of 0.36) of arla.

> Now I want to do everything from makefile and so I am following
> arla's example but I cannot get the resulting extention to load.

It might be so that the makefiles isn't completely up to date on loading on
Mac OS X, build the kernel module should be ok thougth. Do you get any help
in kmsg (print it with dmesg) when you try to load it ?

> It tells me that the extention contains no module code and refuses
> to load.  What are the key characteristics of a kext that enables
> it to load.  What does:  
>
>         echo _xfs_mod > symb.tmp
>>>	: -c symb.tmp tmp.o

: is the 'null' command it does nothing. On some platforms the program
symorder needs to run on the object file to make possible to load it into
the kernel. On all platforms there there isn't a symorder program, we
replace it with the null command. MacOS X/Darwin doesn't use symorder.

If you look at the startarla script I think you'll understand better how
xfs/nnpfs is loaded.

[badboll:/usr/arla/bin] lha% grep xfs.kext /usr/arla/sbin/startarla 
  kextload -s $VARDB $LKMDIR/xfs.kext
[badboll:/usr/arla/bin] lha% find xfs.kext
xfs.kext
xfs.kext/Contents
xfs.kext/Contents/Info.plist
xfs.kext/Contents/MacOS
xfs.kext/Contents/MacOS/xfs


Love