booting on embedded planet RPX_LITE-DW (823e)

booting on embedded planet RPX_LITE-DW (823e)

[curt brune]

Hello,

More news from the home front -- I have made some progress booting
this board, but still have some problems.

The big break through was how to execute a kernel image once
downlaoded via tftp.  With my default boot loader I can load an image
via tftp to any address. Typically I +load the image at 0x4000000 like
this:

>> Load using tftp via Ethernet
>> Enter server IP address <10.0.0.1> :
>>
>> Enter server filename   <ppc-zImage> :
>>
>> Enter (B)inary or (S)record input mode <S> : B
>> B
>> Enter address offset  : <00400000 hex> :
>>
>> .512.1024..2048....4096.
>> Total bytes = 2611354 in 7799788 uSecs
>> Loaded addresses 00400000 through 0067D899.
>> Start address = 00400000
>> >go 410000
>>
>> loaded at:     00410000 0067F210
>> relocated to:  00180000 003EF210
>> board data at: 003EC144 003EC160
>> relocated to:  003EC128 003EC144
>> zimage at:     00185950 00200389
>> initrd at:     00201000 003EBA4A
>> avail ram:     003F0000 01000000
>>
>> Linux/PPC load: console=/dev/ttyS00 root=/dev/ram

Note, however that I jump to 0x410000, not the 0x400000 where I loaded
the image.  A kind soul informed me that I had to start execution at
an offset of 0x10000 from where I load the image.  That really helped
me a lot, since trying to execute at 0x400000 would just hang at the go.

Does anyone know a reason for the 0x10000 offset?  Can you point me to
the documentation ?  Also what do the two columns of addresses mean in
the above output ?  Subsequent to this break through, however, I am
stuck at the "Linux/PPC load:" line.  The system just hangs here.  I
would have expected to see messages like:

>> Uncompressing Linux...done.
>> Now booting the kernel
>> Linux version 2.4.4 ....
>> .....

But I get nothing.  It is as if the uncompression code is not being
run.  Anyone have any ideas on how to get past this step?

I thought it might be my serial port is not configured properly.
Maybe the system is booting, but I'm not seeing anything over the
serial line.  In the documentation for my board it says the serial
port is SMC1 and the ethernet is SMC2.  In the kernel config I see
options for setting the ethernet to SMC1-SMC3, but I do not see
anything about setting the serial port to SMC1.  Could that be a
problem?

For the curious the docs for my board are located here:
http://www.embeddedplanet.com/pdf/docs/lite_um.pdf

Any ideas?

I do appreciate your time, really.  I'm doing this as a hobby --
nobody is going to get rich if I can get this board to boot :)

Cheers,
Curt


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Re: booting on embedded planet RPX_LITE-DW (823e)

[Wolfgang Denk]

Hi Curt,

in message <20020910051430.GA1543@lenin.net> you wrote:
>
> Note, however that I jump to 0x410000, not the 0x400000 where I loaded
> the image.  A kind soul informed me that I had to start execution at
> an offset of 0x10000 from where I load the image.  That really helped
> me a lot, since trying to execute at 0x400000 would just hang at the go.
>
> Does anyone know a reason for the 0x10000 offset?  Can you point me to

It seems you are loading a file in ELF format. 0x10000  is  64  kB  -
this  size  of  the ELF file header. In the Pre-PPCBoot times when we
still used this  bootstrap  loader  method  for  booting  we  alsways
stipped  this  header  - this saves 64 kB (more than 10% of the image
size!) in flash:

	dd if=zImage of=zImage.raw bs=64k skip=1

> the documentation ?  Also what do the two columns of addresses mean in
> the above output ?  Subsequent to this break through, however, I am

These are the start and end addresses of the respective memory  areas
used by your bootstrap loader code.

> stuck at the "Linux/PPC load:" line.  The system just hangs here.  I
> would have expected to see messages like:
>
> >> Uncompressing Linux...done.
> >> Now booting the kernel
> >> Linux version 2.4.4 ....
> >> .....
>
> But I get nothing.  It is as if the uncompression code is not being
> run.  Anyone have any ideas on how to get past this step?

Attach a debugger? Do you have access to a BDI2000?

> I thought it might be my serial port is not configured properly.
> Maybe the system is booting, but I'm not seeing anything over the
> serial line.  In the documentation for my board it says the serial
> port is SMC1 and the ethernet is SMC2.  In the kernel config I see

This is impossible. The SMC ports cannot be used for Ethernet. I  bet
you mistake this for SCCx.

> options for setting the ethernet to SMC1-SMC3, but I do not see

No, again, this is SCCx - there is not even a SMC3.

> anything about setting the serial port to SMC1.  Could that be a
> problem?

SMC1 is enabled as serial console port by default.  In  the  standard
kernel there is no configuration option for this.

> I do appreciate your time, really.  I'm doing this as a hobby --
> nobody is going to get rich if I can get this board to boot :)

Good luck!

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
At the source of every error which is blamed on the computer you will
find at least two human errors, including the error of blaming it  on
the computer.

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Re: booting on embedded planet RPX_LITE-DW (823e)

[curt brune]

Success!!  It boots!

Thanks to all the people who pointed this out:

> > Does anyone know a reason for the 0x10000 offset?  Can you point
    me to
>
> It seems you are loading a file in ELF format. 0x10000  is  64  kB
    -
> this  size  of  the ELF file header. In the Pre-PPCBoot times when we
> still used this  bootstrap  loader  method  for  booting  we  alsways
> stipped  this  header  - this saves 64 kB (more than 10% of the  image
> size!) in flash:
>
>       dd if=zImage of=zImage.raw bs=64k skip=1
>

Regarding my hanging problem -- this was board specific.  My board has
a watchdog timer, which was enabled.  After disabling this via the
"SYPCR" config parameter it just worked.  Great.  Good feeling.

It even netboots.  Great.

For what it's worth I'm running kernel 2.4.18 patched with
ppc-patch-2.4.18.gz from kernel.org .  For the toolchain I'm using the
ELDK.  No other patches.

Now the real big fun begins.

Cheers,
Curt

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