Re: boot/simple in ROM?

Re: boot/simple in ROM?

[Jerry Van Baren]

The "simple" boot loaders are loaders, they are NOT bootroms.  They expect
the board to have a firmware/bootrom/monitor that does the necessary very
low level very hardware specific initialization (things like setting up
memory maps, initializing the SDRAM controller, etc.).  The "simple" boot
loaders do the added steps necessary for starting linux, so they are
necessary but NOT sufficient.

gvb


At 01:32 PM 4/24/2003 -0400, kentborg@borg.org wrote:

>On Thu, Apr 24, 2003 at 01:13:35PM -0400, Dan Malek wrote:
> > The other really nice thing about these bootloaders, compressed
> > kernels, and attached initrd, is you can boot the identical image
> > from all "devices."  For example, during development you can tftp
> > load the image, get everything working, then place the exact same
> > bits into a flash rom.  Simply jump to the first location of the
> > image and it will boot from flash.
>
>Yes, but disappointingly the ppc/boot/simple I am using (from 2.4
>devel) won't run from ROM.  Is there a better boot loader I should be
>using?
>
>Thanks,
>
>-kb
>


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Re: boot/simple in ROM?

[Mark A. Greer]

Jerry Van Baren wrote:

>
> The "simple" boot loaders are loaders, they are NOT bootroms.  They
> expect
> the board to have a firmware/bootrom/monitor that does the necessary very
> low level very hardware specific initialization (things like setting up
> memory maps, initializing the SDRAM controller, etc.).  The "simple" boot
> loaders do the added steps necessary for starting linux, so they are
> necessary but NOT sufficient.

In general this is true.  However, it is possible to put enough hw init
in the simple boot loader (bootwrapper as I and others now call it) to
run linux.  This has been done in the past.

Mark


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Basic Config file

[Kevin A. Sapp]

Hello all,

I recently downloaded and installed the ELDK under RedHat
8 targeting a 74xx.  Everything went pretty smooth (Thanks
Wolfgang!).  I am utterly inexperienced at building the
kernel.  This is the first one.  I have everything compiling,
but getting various linker unresolves.

Can someone point me to or send a simple config file as an
example?  As few components as possible would be great.

Thank you
Kevin


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Re: Basic Config file

[Kevin A. Sapp]

Read the ELDK manual, however, did not see anything
on the kernel configuration and building it.  Went to
kernelnewbies for that...anywhere else I can go for
kernel configuration.

Unresolveds are:
va_to_pte and get_IMMR in traps.c
the get_IMMR seems to be 8xx specific.
va_to_pte is in several headers for asm code,
but grep of the source tree does not show any
implementations in *.[Sch]

Thanks
Kevin


emanuel stiebler wrote:

> Kevin A. Sapp wrote:
>
>>
>> Hello all,
>>
>> I recently downloaded and installed the ELDK under RedHat
>> 8 targeting a 74xx.  Everything went pretty smooth (Thanks
>> Wolfgang!).  I am utterly inexperienced at building the
>> kernel.  This is the first one.  I have everything compiling,
>> but getting various linker unresolves.
>
>
> Can you tell us more what unresolves you get ?
>
>> Can someone point me to or send a simple config file as an
>> example?  As few components as possible would be great.
>
>
> Try the defaults first.
> I assume you read the documentation, right ?
> ;-)
>
> cheers
>
>


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Re: Basic Config file

[Wolfgang Denk]

In message <3EA84246.9050101@catapult.com> you wrote:
>
> Read the ELDK manual, however, did not see anything
> on the kernel configuration and building it.  Went to
> kernelnewbies for that...anywhere else I can go for
> kernel configuration.

There is also  http://www.denx.de/re/DPLG.html  (but  this  does  not
answer the details of kernel configuration - it only describes how to
use  existing  default  configs). In all other cases you just have to
know what you are doing.

> Unresolveds are:
> va_to_pte and get_IMMR in traps.c
> the get_IMMR seems to be 8xx specific.
> va_to_pte is in several headers for asm code,
> but grep of the source tree does not show any
> implementations in *.[Sch]

It's a bug. Both EXPORT_SYMBOL()s are  8xx  specific.  Fixed  in  our
current CVS.


Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
A dog always bit deepest on the veterinary hand.
                                    - Terry Pratchett, _Wyrd Sisters_

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