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* monitor in mpc860fads
@ 2002-02-26  9:16 gao xiaoguo
  2002-02-26 10:35 ` execve system call question Sangmoon Kim
  0 siblings, 1 reply; 17+ messages in thread
From: gao xiaoguo @ 2002-02-26  9:16 UTC (permalink / raw)
  To: linuxppc-embedded


hi,

now i have a mpc860fads board, maybe there is a debug monitor inside it.
but i dont know how to check it. i also dont know what i need on host end to communicate with the monitor. some guide book is appreciated.

I am newbie in this area, hope some expertise point out a way for me.

thanks


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

^ permalink raw reply	[flat|nested] 17+ messages in thread
* RE: execve system call question
@ 2002-02-26 14:34 Derrik Weeks
  2002-02-27  1:31 ` Sangmoon Kim
  0 siblings, 1 reply; 17+ messages in thread
From: Derrik Weeks @ 2002-02-26 14:34 UTC (permalink / raw)
  To: 'Sangmoon Kim', linuxppc-embedded


Hi,

This sounds like a problem I had a while back with the location of the IMMR
of on my processor.  What I discovered (via the archives of this mail list)
is the IMMR needs to be located in high memory above F0000000.  Check your
code to see if the memory map for your custom board has placed the IMMR at a
low memory address.

>From experience I know that if this is your issue, your kernel will crash
whether you're running NFS or a ram disk.  Once you move the IMMR to high
memory, you'll get to shell prompt with no problem.  I'm 75% sure you're
looking at the same situation as I was, but if not, I wish you luck in your
troubleshooting.

>From what I can tell by my limited time on this mail list, this issue has
snagged many people new to Linux.  It's apparently well known in lore that
the IMMR needs to be in high memory, it's just not particularly well
documented, although those details can be found with enough digging.

Hope this helps!
Derrik Weeks
Digital Hardware Architect
IOtech, Inc.

-----Original Message-----
From: Sangmoon Kim [mailto:dogoil@etinsys.com]
Sent: Tuesday, February 26, 2002 5:35 AM
To: linuxppc-embedded
Subject: execve system call question



Hi!
I'm debugging a custom MPC755 board
with linuxppc_devel from montavista rsync,
and /opt/hardhat/devkit/ppc/7xx/target for NFS root.
It booted and stoped after the message.

--------------------------------------------------------
NET4: Linux TCP/IP 1.0 for NET4.0
IP Protocols: ICMP, UDP, TCP
IP: routing cache hash table of 1024 buckets, 8Kbytes
TCP: Hash tables configured (established 8192 bind 8192)
IP-Config: Complete:
      device=eth0, addr=203.239.17.200, mask=255.255.255.0,
gw=203.239.17.57,
     host=dogoil, domain=, nis-domain=(none),
     bootserver=203.239.17.57, rootserver=203.239.17.57, rootpath=
NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
Looking up port of RPC 100003/2 on 203.239.17.57
Looking up port of RPC 100005/1 on 203.239.17.57
VFS: Mounted root (nfs filesystem).
Freeing unused kernel memory: 76k init
--------------------------------------------------------

I traced the code and the point of stopping is after calling
execve("/sbin/init", argv_init, envp_init)
in init/main.c

I was trying to trace more, but it was impossible
because of the complexity of the code.

Is there any method to debug this?
I'm debugging it for a month.

Please help me.

- Sangmoon Kim -


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

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[parent not found: <69BCCDDC980B4641BFC908D7BF95F1842A4B89@exchsrv-eng>]
[parent not found: <21A8AE56EBB6D411A4520060973D360179DD48@pepintercom.pep.de>]
[parent not found: <C08678384BE7D311B4D70004ACA371050B7632EC@amer22.avnet.com>]
* RE: execve system call question
@ 2002-02-27 14:33 Derrik Weeks
  2002-03-04  1:11 ` Sangmoon Kim
  0 siblings, 1 reply; 17+ messages in thread
From: Derrik Weeks @ 2002-02-27 14:33 UTC (permalink / raw)
  To: 'Sangmoon Kim', Derrik Weeks, linuxppc-embedded


Greetings Sangmoon,

My apologies, I thought that most PPC based chips had configuration or
status registers that were not in the SPR space (i.e. IMMR based regs).  A
little research says this is not the case.  As I understand it (with thanks
to Wolfgang) Linux reserves memory space below 80000000 for user
applications.  In my case I had my IMMR based registers mapped below this
value, and the kernel was setting mapping for this space to virtual =
physical, which caused my problem.  You may have the same issue with your
serial port, it would be worth a try to move it to high memory and see if
this resolves your problem.

Best of luck,
Derrik Weeks

-----Original Message-----
From: Sangmoon Kim [mailto:dogoil@etinsys.com]
Sent: Tuesday, February 26, 2002 8:31 PM
To: Derrik Weeks; linuxppc-embedded
Subject: Re: execve system call question


Hi Derrik Weeks!

> IMMR needs to be located in high memory above F0000000.

The MPC755 doesn't have an IMMR.
If it is because all the I/O should be locaced above F0000000, please let me
know. The serial port of my board is located at 0x78000000.

> kernel will crash whether you're running NFS or a ram disk.

You are right I tried ramdisk but kernel crashed.

Thank you for the reply.

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

^ permalink raw reply	[flat|nested] 17+ messages in thread
[parent not found: <C08678384BE7D311B4D70004ACA371050B7632EF@amer22.avnet.com>]

end of thread, other threads:[~2002-03-04  1:20 UTC | newest]

Thread overview: 17+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2002-02-26  9:16 monitor in mpc860fads gao xiaoguo
2002-02-26 10:35 ` execve system call question Sangmoon Kim
2002-02-26 13:11   ` None Atall
2002-02-27  1:21     ` Sangmoon Kim
2002-02-27  7:54       ` Wolfgang Denk
2002-02-26 13:21   ` Wolfgang Denk
2002-02-27  1:36     ` Sangmoon Kim
2002-02-26 13:27   ` Christian Pellegrin
2002-02-27  1:23     ` Sangmoon Kim
  -- strict thread matches above, loose matches on Subject: below --
2002-02-26 14:34 Derrik Weeks
2002-02-27  1:31 ` Sangmoon Kim
     [not found] <69BCCDDC980B4641BFC908D7BF95F1842A4B89@exchsrv-eng>
2002-02-27  1:41 ` Sangmoon Kim
     [not found] <21A8AE56EBB6D411A4520060973D360179DD48@pepintercom.pep.de>
2002-02-27  1:45 ` Sangmoon Kim
     [not found] <C08678384BE7D311B4D70004ACA371050B7632EC@amer22.avnet.com>
2002-02-27  1:48 ` Sangmoon Kim
2002-02-27 14:33 Derrik Weeks
2002-03-04  1:11 ` Sangmoon Kim
     [not found] <C08678384BE7D311B4D70004ACA371050B7632EF@amer22.avnet.com>
2002-03-04  1:20 ` Sangmoon Kim

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