MC850 peripheral support in linux
wd at denx.de
Fri Mar 26 22:55:49 EST 2004
In message <s063f6d1.092 at EMAIL> you wrote:
> I plan to use the latest ELDK from DENX
> Is there any known problems in ELDK Distro?
Yes, a few.
* The static microwindows libraries were stripped and are useless
for linking; updated RPM's are available.
* The index for the local RTC has changed in the NTPD source so you may
need to adapt your /etc/ntp.conf file; documentation was updated at
> I could see that the ELDK distro is well packed with all toolchains,
> kernel and applications.
> I could no find out the "target filesystem" ?
If you install for example the "ppc_8xx" packages to the default
location /opt/eldk, then /opt/eldk/ppc_8xx/ will be the root
directory of your target filesystem. You can use this and export it
on a NFS server; see the detailed documentation in the DULG.
> Should the target filesystem be created manually from the directory
> into which I install all the application RPMs.? Is there any script
> files already available doing the same.
If you're talking about a standlone target filesystem you can use the
SELF package; eitehr by using the SELF source RPM and modifying the
build script, or by using the pre-build images in
/opt/eldk/ppc_8xx/images/ and modifying those as documented, see
Or you can start from scratch using the standard tools like
genext2fs, mkcramfs, mkfs.jffs2, etc.
> How is the kernel and rotofs attachment done ?
We normally use U-Boot to boot LInux. Just read the DULG for details:
> Do I need o do it with my bootloader passing command line arguments to
> the kernel ? (I plan to use u-boot).
Read the DULG.
> > Don't expect too much of performance out of a 850; the tiny
> > a major pain.
> As far as performance is considered, I do not need very high.
> Out of curisity, what exactly is the problem ?
As I wrote: it's the tiny caches. Performance on RISC processors like
the PowerPC stands and falls witch cache size. A PowerPC processor
with only 2 kB Instruction Cache and 1 kB Data Cache like the MPC850
performs as castrated.
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
It's a small world, but I wouldn't want to paint it.
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