AW: Linux 2.4.24 on PQ2FADS

Stefano Gaiotto Stefano.Gaiotto at
Wed Mar 10 03:04:42 EST 2004


I had not an entry for Hip7 such that you send me! Thak you very much for
your help.
I'm going to chek my SDRAM initialization because, now, I see corrupted
stamps, like these:

## Booting image at 00100000 ...
   Image Name:   2.2.4 Kernel for PQ2FADS
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    571353 Bytes = 558 kB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
   Uncompressing Kernel Image ... OK
Memory BAT mapping: BAT2=32Mb, BAT3=0Mb, residual: 0Mb
                                                      ÀLinux version 2.4.24
otto at gexs22) (gcc version 3.3.2) #5 Tue Mar 9 17:00:09 CET 2004
                                                               ÀADS setup
n node 0 totalpages: 8192
                         Àzone(0): 8192 pages.
                                              Àzone(1): 0 pages.
                                                                Àzone(2): 0
  ÀKernel command line: root=/dev/nfs rw
dsroot nobats ip=
 ÀÀÀÀ$                 ÀADS init IRQ. NR_IRÀÀÀÀÀ


Thomas Schäfer <tschaefer at> on 09/03/2004 14:24:39

Please respond to <tschaefer at>

To:    "Stefano Gaiotto" <Stefano.Gaiotto at>
cc:    <linuxppc-embedded at>

Subject:    AW: Linux 2.4.24 on PQ2FADS

Hi Stefano,

just a wild guess:

check the cpu_specs[] array in your arch/ppc/kernel/cputable.c file. It
contain something like this entry for your 8275 CPU:

    { /* 82xx (Hip7 603e cores) */
      0xffff0000, 0x80820000, "82xx (Hip7)",
      32, 32,

The CPU ID (0x80820000 in this case) must match your 8275 CPU ID.
Otherwise, generic PPC
will be assumed which leads to strange behaviour as soon as the MMU will be
enabled by
the kernel.

second guess:

Because of the random errors you described I would check the SDRAM settings
of the board:
- check ALL settings of the memory controller against the settings
described in the
  data sheet of your SDRAM.
- check memory controller initialization sequence against the sequence
described in the
  data sheet of the SDRAM and the memory controller of the CPU
- if both are correct: check signal integrity on your board

hope this helps.

Best regards,

Thomas Schaefer

> -----Ursprüngliche Nachricht-----
> Von: owner-linuxppc-embedded at
> [mailto:owner-linuxppc-embedded at]Im Auftrag von
> Stefano Gaiotto
> Gesendet: Dienstag, 9. März 2004 13:53
> An: linuxppc-embedded at
> Betreff: Linux 2.4.24 on PQ2FADS
> Dear colleagues,
> I'm trying to have Linux 2.4.24 working on my evaluation board PQ2FADS-VR
> with ppc8275, but I'm suffering of a lot of instability problems.
> The Boot-loader I use is Uboot-1.0.0 witch initialise correctly the board
> at speed 66,133,199 and correctly fills bd_info struct.
> But when I issue the command "=> bootm 100000" I observe every time a
> different behaviour: sometimes I don't see anything, sometimes the board
> stops in "Calibrating delay loop", sometimes after having written
> the line:
> Memory: 30936k available (984k kernel code, 344k data, 52k init, 0k
> highmem)
> Or the line
> POSIX conformance testing by UNIFIX
> Only occasionally it reaches the init program (stopping here).
> The same behaviour I observed with the images delivered by the Arabella
> distribution!
> Do you have any suggestion? MMU? Cache? Hardware?
> Thanks in advance for your advice.
> With best regards,
> Stefano

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