MC850 peripheral support in linux

MC850 peripheral support in linux

[Rupesh S]

Hi

I would like to know from all your experiences, if the following works well in the Linux-ppc port for MC850

1) Does the I2C bus support in the kernel works for the internal I2C controller of MC850
2) Does the RTC support in the kernel (char driver) works for the internal RTC of MC850
3) Does the PCMCIA support in the kernel (IDE drivers)  works for the internal PCMCIA Socket controller of MC850

I could find these supports in the latest ppc kernel. Since I don't have a hardware right now with me, so I am unable to test all these. I thought I will take all your help to confirm these facts.

This is to help me finalizing Linux for one of my Embedded Projects that will be built on MC850.





Thanks
--
Rupesh S


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Re: MC850 peripheral support in linux

[Wolfgang Denk]

In message <s0632321.003@EMAIL> you wrote:
>
> 1) Does the I2C bus support in the kernel works for the internal I2C controller of MC850
> 2) Does the RTC support in the kernel (char driver) works for the internal RTC of MC850
> 3) Does the PCMCIA support in the kernel (IDE drivers)  works for the internal PCMCIA Socket controller of MC850

3 x yes. But I can only speak of the DENX kernel trees.

> This is to help me finalizing Linux for one of my Embedded Projects that will be built on MC850.

Don't expect too much of performance out of a 850;  the  tiny  caches
are a major pain.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
There are three things I always forget. Names, faces -  the  third  I
can't remember.                                         - Italo Svevo

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Re: MC850 peripheral support in linux

[Rupesh S]

Hi ,

>> 1) Does the I2C bus support in the kernel works for the internal I2C
controller of MC850
>> 2) Does the RTC support in the kernel (char driver) works for the
internal RTC of MC850
>> 3) Does the PCMCIA support in the kernel (IDE drivers)  works for
the internal PCMCIA Socket controller of MC850

> 3 x yes. But I can only speak of the DENX kernel trees.

I plan to use the latest ELDK from DENX
Is there any known problems in ELDK Distro?
I could see that the ELDK distro is well packed with all toolchains,
kernel and applications.
I could no find out the "target filesystem" ?
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.

How is the kernel and rotofs attachment done ?
Do I need o do it with my bootloader passing command line arguments to
the kernel ? (I plan to use u-boot).

> Don't expect too much of performance out of a 850;  the  tiny
caches
> a major pain.

As far as performance is considered, I do not need very high.
Out of curisity, what exactly is the problem ?




Thanks
--
Rupesh S

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Re: MC850 peripheral support in linux

[Wolfgang Denk]

In message <s063f6d1.092@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
  http://www.denx.de/twiki/bin/view/DULG/UseNTPToSynchronizeSystemTimeAgainstRTC

> 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
http://www.denx.de/twiki/bin/view/DULG/HowToAddFiles and
http://www.denx.de/twiki/bin/view/DULG/HowToIncreaseSizeOfRamdisk

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:
http://www.denx.de/twiki/bin/view/DULG/Manual

> 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
> caches
> > 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.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
It's a small world, but I wouldn't want to paint it.

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