Re: Status of MPC823FADS port

Re: Status of MPC823FADS port

[@Jean-Jacques GERMOND]

a) Which are the good chips?
----------------------------

 In an email dated Sep/03, Dan Malek states:
 
 --->  I don't recommend using any (F)ADS board with Linux/PPC.
 
 To add to the fun, I now understand that we also have to take into
 consideration the mpc8xx revision number whatever the board is.
 
 I have linux 2.2.7 running bash and few basic utilities
 on a "streamaster" board from Motorola with the following chip
 references:
 
     XPC860SRZ P66 C1
        2H96G
     IMMR=A0000031
 
 Many thanks to the Linux community for that.
 
 Then I just spent two horrible months trying to port this 2.2.7 code
 on several (F)ADS board(s) with  mpc823, mpc823e and other mpc860
 variants without significant success due to many problems,
 mostly in the MMU.
 
 Specifically the following chip does not seem to work:
 
     MPC823e Silicon Revision B.0
       Mask Set 0J13D
      IMMR=02202400
 
 Wolfgang Denk <wd@denx.de> was kind enough to check this IMMR value at:
    http://www.mot.com/SPS/ADC/pps/subpgs/sse/823/index.html
 and email me:
 
 --->  Ummm... are you still wondering why you have problems? I'm not.
 --->  Your silicon is BROKEN, don't waste any more time on it.
 --->  ....
 --->  Make sure to run the latest revision (at least C.0) of silicon!
 --->  ....
 
 I can find C.0 rev. nbr. of MPC860 chip but the MPC823e seems to be an
 other issue.

b) Which are the good boards?
-----------------------------

 In the above mail, Dan states:
 
 --->  With high quality boards available from a variety of sources
 --->  today, there is no need for the agony of using a (F)ADS board.
 
 May be the ppc linux community could maintain a list of such boards along
 with processors rev. number and linux versions that are known to work?
 I do not know how to get such a list started and maintained.
 
 Meanwhile, can anyone send me references of such "high quality boards"
 specifically for the mpc823e on which Linux is known to run.  
 I am ready to order.  Please, use private mail, if you do not want
 to post something that may look commercial.

c) The M_TWB issue
------------------
 
 There has been some discussion this year about the mpc8xx crashing
 when we setup the M_TWB register.  the MPC860 user's
 manual (9.8 Programming model) states that:
 
      "These (M_xxx) SPRs should be accessed when both instruction
      and data address translation is disabled"
 
 In a private mail, Motorola told me that this restriction apply
 to these SPRs setup as well (a dubious feature).
 
 So, I wrote a small asm routine to sedtup these registers from
 the mapped mode:

      -switch to unmapped mode
      -setup M_TWB and optionally M_CASID
      -return to the caller in mapped mode.
 
 I will post the source if asked too, but this mail is too long already.
 
 With this code, my MPC823(e) work much better (ie: they don't crash so fast).
 The 2.2.7 switch is marginally slower but since I don't manage
 yet to execve anything in init ....

d) Extracting the page number.
-----------------------------
 
 In the file .../kernel/head.s, the following stmt. is used in several
 locations:
 
 	rlwinm.	r20, r21,0,0,20	/* Extract page descriptor page address */
 
 This must be fine, but what about this other statement instead:
 
 	rlwinm.	r20, r21,0,0,19	/* Extract page descriptor page address */
 
 
e) The 2.3.18 version
---------------------

 This version appears to be very promising and should solve many
 of the above hw problems. It however does not run yet on any of
 my machines because the ramdisk does not seem to work yet.
 Please keep me posted.
 
Whatever the difficulties, it's great working with Linux.

Jean-Jacques Germond


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Re: Status of MPC823FADS port

[Richard Hendricks]

@Jean-Jacques GERMOND wrote:
> 
> a) Which are the good chips?
> ----------------------------
> 
>  In an email dated Sep/03, Dan Malek states:
> 
>  --->  I don't recommend using any (F)ADS board with Linux/PPC.
> 
>  To add to the fun, I now understand that we also have to take into
>  consideration the mpc8xx revision number whatever the board is.
> 
>  I have linux 2.2.7 running bash and few basic utilities
>  on a "streamaster" board from Motorola with the following chip
>  references:
> 
>      XPC860SRZ P66 C1
>         2H96G
>      IMMR=A0000031
> 
>  Many thanks to the Linux community for that.
> 
>  Then I just spent two horrible months trying to port this 2.2.7 code
>  on several (F)ADS board(s) with  mpc823, mpc823e and other mpc860
>  variants without significant success due to many problems,
>  mostly in the MMU.

There are only really two functional differences in the MMU/caches
between the 860 and the MPC823.  The MPC823 has 8 TLBs, and 2k I/
1k D cache.  The MPC823E has 32 TLBs and 16k I/ 8k D cache.
The MPC860 has 32 TLBs and 4k I/ 4k D cache.  Other than that,
there are no core differences between the MPC823/MPC823e/MPC860
other than that listed in the errata.

>  Specifically the following chip does not seem to work:
> 
>      MPC823e Silicon Revision B.0
>        Mask Set 0J13D
>       IMMR=02202400

Revision B.0 silicon on the MPC823e is old.  In fact, it
was only an engineering mask.  Rev B.2 is the latest 
MPC823e silicon.

Not to say there isn't a problem.  What frequency are you trying
to run the MPC823e at?  It's bus? What is it spec'd for?
Does it work at a lower frequency but not a higher one?

>  Wolfgang Denk <wd@denx.de> was kind enough to check this IMMR value at:
>     http://www.mot.com/SPS/ADC/pps/subpgs/sse/823/index.html
>  and email me:
> 
>  --->  Ummm... are you still wondering why you have problems? I'm not.
>  --->  Your silicon is BROKEN, don't waste any more time on it.
>  --->  ....
>  --->  Make sure to run the latest revision (at least C.0) of silicon!
>  --->  ....

Contrary to popular belief, the MPC8xx parts do not all get revised
together.  Revision B of the MPC823 is much, much newer than say, 
revision B of the MPC821.  Revision B2 of the MPC823E is the latest
silicon.
 
>  I can find C.0 rev. nbr. of MPC860 chip but the MPC823e seems to be an
>  other issue.

It is.  They are both now owned by the same division, but weren't
originally, and so they have different versions.
 
> b) Which are the good boards?
> -----------------------------
> 
>  In the above mail, Dan states:
> 
>  --->  With high quality boards available from a variety of sources
>  --->  today, there is no need for the agony of using a (F)ADS board.

Dan was never very specific as to the exact problems he had.  I
don't know, for example, if he was using an old (F)ADS board that
had some problems, or just was unlucky and got a bad board.  What I 
can say is that our Windows CE team here has successfully ported
Windows CE to both the MPC821 and MPC823 with the (F)ADS boards,
including PCMCIA, Ethernet, LCD Controller, and the SCC and SMC.
Both the original ADS and the FADS.  In fact, we made some 100 
plastic-enclosed systems for them to use for their development.
Out of all the (F)ADS I have seen, I have only seen one case where
there was a questionable daughtercard.
 
>  May be the ppc linux community could maintain a list of such boards along
>  with processors rev. number and linux versions that are known to work?
>  I do not know how to get such a list started and maintained.
> 
>  Meanwhile, can anyone send me references of such "high quality boards"
>  specifically for the mpc823e on which Linux is known to run.
>  I am ready to order.  Please, use private mail, if you do not want
>  to post something that may look commercial.

I have heard good things about the Embedded Planet (formerly RPCg)
RPX series of boards.  I don't know if they have any MPC823e
based products as of yet.  (This does not serve as any sort of
endorsement of Embedded Planet by Motorola, etc etc yadda yadda.)

> c) The M_TWB issue
> ------------------
> 
>  There has been some discussion this year about the mpc8xx crashing
>  when we setup the M_TWB register.  the MPC860 user's
>  manual (9.8 Programming model) states that:
> 
>       "These (M_xxx) SPRs should be accessed when both instruction
>       and data address translation is disabled"

When doing a TLB reload, unless you specifically turn address
translation back on in your interrupt routine, address translation
is disabled.
 
>  In a private mail, Motorola told me that this restriction apply
>  to these SPRs setup as well (a dubious feature).

?
 
>  So, I wrote a small asm routine to sedtup these registers from
>  the mapped mode:
> 
>       -switch to unmapped mode
>       -setup M_TWB and optionally M_CASID
>       -return to the caller in mapped mode.
> 
>  I will post the source if asked too, but this mail is too long already.
> 
>  With this code, my MPC823(e) work much better (ie: they don't crash so fast).
>  The 2.2.7 switch is marginally slower but since I don't manage
>  yet to execve anything in init ....
> 
> d) Extracting the page number.
> -----------------------------
> 
>  In the file .../kernel/head.s, the following stmt. is used in several
>  locations:
> 
>         rlwinm. r20, r21,0,0,20 /* Extract page descriptor page address */
> 
>  This must be fine, but what about this other statement instead:
> 
>         rlwinm. r20, r21,0,0,19 /* Extract page descriptor page address */
> 
> 
> e) The 2.3.18 version
> ---------------------
> 
>  This version appears to be very promising and should solve many
>  of the above hw problems. It however does not run yet on any of
>  my machines because the ramdisk does not seem to work yet.
>  Please keep me posted.
> 
> Whatever the difficulties, it's great working with Linux.
> 
> Jean-Jacques Germond

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NFS Root

[Claude Robitaille]

Hi,


I am trying to boot my MPC860 board via NFS-Root but I am getting
a -13 error. The board did properly get its IP address from a bootp
server. The server also provided the NFS server address, which the
board properly use. I am able to mount the exported file system using
another client (actually, the bootp server; I have 2 stations plus the
860 board).

Is there a good source of information on NFS other then the HOWTO. It
seems a little bit outdated (early 1997); I am using 2.2.12 with kernel
NFS, etc. And it does not rely help in troubleshooting (i.e. what is
error -13?)

Thanks

Claude


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Re: NFS Root

[Mark S. Mathews]

For us, adding the no_root_squash option to the export usually fixes this
problem.

-Mark

On Fri, 22 Oct 1999, Claude Robitaille wrote:

> 
> Hi,
> 
> 
> I am trying to boot my MPC860 board via NFS-Root but I am getting
> a -13 error. The board did properly get its IP address from a bootp
> server. The server also provided the NFS server address, which the
> board properly use. I am able to mount the exported file system using
> another client (actually, the bootp server; I have 2 stations plus the
> 860 board).
> 
> Is there a good source of information on NFS other then the HOWTO. It
> seems a little bit outdated (early 1997); I am using 2.2.12 with kernel
> NFS, etc. And it does not rely help in troubleshooting (i.e. what is
> error -13?)
> 
> Thanks
> 
> Claude
> 
> 


Mark S. Mathews

AbsoluteValue Software     Web:    http://www.absoval.com
P.O. Box 941149            e-mail: mark@absoval.com
Maitland, FL 32794-1149    Phone:  407.644.8582
USA                        Fax:    407.539.1294


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Re: NFS Root

[Claude Robitaille]

HI,

it is me again, I think my problem comes from mountd since it
is the last entry in the NFS server log. Some NFS related man
page refers to a man page mountd(8) but it was not included
with the knfsd rpm. Anobody has it? I'd like to see if there
is some debugging / authentication options.

Thanks

Claude


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Re: NFS Root - I am further ahead

[Claude Robitaille]

Hi,

finally, all I had to do is to had an entry into /etc/hosts
so that mountd's authentication pass.

Now, on the serial console, I see that the root system is
mounted via NFS and that some memory is freed but then the
systerm hangs there. I did some tcpdump while the board is
booting and I found that:

/sbin/init gets loaded
/lib/ld.so.1 -> ld-2.1.1.so gets also loaded

but this all gets loaded, even if /sbin/init needs libc.so.6
and libutil.so.1 (as indicated by ldd). Is it normal that theses
2 libraries does not get loaded immediately after ld.so.1? If it is,
idea why the system hangs?

Thanks

Claude


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Re: NFS Root - I am further ahead

[Marcus Sundberg]

Claude Robitaille <crobitaille@videotron.ca> writes:

> Hi,
> 
> finally, all I had to do is to had an entry into /etc/hosts
> so that mountd's authentication pass.
> 
> Now, on the serial console, I see that the root system is
> mounted via NFS and that some memory is freed but then the
> systerm hangs there. I did some tcpdump while the board is
> booting and I found that:
> 
> /sbin/init gets loaded
> /lib/ld.so.1 -> ld-2.1.1.so gets also loaded
> 
> but this all gets loaded, even if /sbin/init needs libc.so.6
> and libutil.so.1 (as indicated by ldd). Is it normal that theses
> 2 libraries does not get loaded immediately after ld.so.1?

They would, unless ld-2.1.1.so crashed.

> If it is, idea why the system hangs?

Sounds like you haven't made the highly needed MPC8xx modifications
to glibc. See the archive of this list.

//Marcus
-- 
-------------------------------+------------------------------------
        Marcus Sundberg        | http://www.stacken.kth.se/~mackan/
 Royal Institute of Technology |       Phone: +46 707 295404
       Stockholm, Sweden       |   E-Mail: mackan@stacken.kth.se

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Re: NFS Root - I am further ahead

[Claude Robitaille]

hi Marcus,

I've just downloaded libc-1.99-8xx from linuxppc.cs.nmt.edu
and tried it but without success. Is that library known to work?
I presume so but I am asking just in case.

Claude

On Sun, 24 Oct 1999, Marcus Sundberg wrote:

> 
> Claude Robitaille <crobitaille@videotron.ca> writes:
> 
> > Hi,
> > 
> > finally, all I had to do is to had an entry into /etc/hosts
> > so that mountd's authentication pass.
> > 
> > Now, on the serial console, I see that the root system is
> > mounted via NFS and that some memory is freed but then the
> > systerm hangs there. I did some tcpdump while the board is
> > booting and I found that:
> > 
> > /sbin/init gets loaded
> > /lib/ld.so.1 -> ld-2.1.1.so gets also loaded
> > 
> > but this all gets loaded, even if /sbin/init needs libc.so.6
> > and libutil.so.1 (as indicated by ldd). Is it normal that theses
> > 2 libraries does not get loaded immediately after ld.so.1?
> 
> They would, unless ld-2.1.1.so crashed.
> 
> > If it is, idea why the system hangs?
> 
> Sounds like you haven't made the highly needed MPC8xx modifications
> to glibc. See the archive of this list.
> 
> //Marcus
> -- 
> -------------------------------+------------------------------------
>         Marcus Sundberg        | http://www.stacken.kth.se/~mackan/
>  Royal Institute of Technology |       Phone: +46 707 295404
>        Stockholm, Sweden       |   E-Mail: mackan@stacken.kth.se
> 
> 


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Re: NFS Root - I am further ahead

[Dan Malek]

Marcus Sundberg wrote:


> Sounds like you haven't made the highly needed MPC8xx modifications
> to glibc. See the archive of this list.

Those are not needed at this point unless you are running with
copyback data cache enabled.  I don't think the kernel normally
sets this mode (in head.S) because you can run with the standard
distribution files and libraries.

Normally, at this point I find the console device isn't working
correctly.  That is, the NFS server isn't properly handling things
in /dev, the symbolic link of /dev/console is wrong, or the
/dev/console node itself isn't correct.


	-- Dan

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Re: NFS Root - I am further ahead

[Dan Malek]

Claude Robitaille wrote:
> 
> hi Marcus,
> 
> I've just downloaded libc-1.99-8xx from linuxppc.cs.nmt.edu
> and tried it but without success. Is that library known to work?

Yep, I use it all of the time.  It was compiled from the "-o"
version of the source RPM (I don't remember the entire version
string), with the -mcpu=860 flag and with the cache line size
patched to match the 8xx.


	-- Dan

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Re: NFS Root - I am further ahead

[Claude Robitaille]

Hi all,


> 
> Normally, at this point I find the console device isn't working
> correctly.  That is, the NFS server isn't properly handling things
> in /dev, the symbolic link of /dev/console is wrong, or the
> /dev/console node itself isn't correct.
> 
I am using the dev directory found in mbxroot_min_tgz so I am 
assuming this is ok.

Does any one know if all of a program's dynamic libraries are loaded
upon startup of it or are they just loaded when needed? I think it is
the later so the clue of not seeing all the library read (looking at
tcpdump) does not tell anything.

I try to put a printf at the beginning of init but it does not
show up. I guess this does not say much...

Other idea(s)?

Claude


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