[U-Boot-Users] SDRAM init, and Chip Selects

Jerry Walden jwalden at digitalatlantic.com
Tue Feb 11 23:51:36 CET 2003 

We have a custom 405GPr PPC Board and are trying to bring u-boot
up on it.

We notice that our bank selects are not going low during a write to SDRAM

How is this possible?

We don't see bank select 0 or bank select 1 toggle during a write cycle to
an address around the range 0x1fd0000 (this is actually during the
relocate_code
part of the boot process)

there are 4 SDRAM chips on the board
we have bank select 0 connected to chip select on the first "bank" (SDRAM
chips
zero and one), and bank select 1 connected to the chip select on the second
"bank" (SDRAM chips 2 and 3).

Hence, our "relocate_code" fails because writing to SDRAM is not functioning
we can verifiy this by looking at memory with the BDI2000 after a write is
attempted.



-----Original Message-----
From: Jerry Walden [mailto:jwalden at digitalatlantic.com]
Sent: Tuesday, February 11, 2003 1:06 PM
To: Chris Hallinan
Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?


I assume you mean by "the code" the code for initializing SDRAM?
If so I have enclosed what we use.  It is based upon a code segment
you sent me in the past, however it was changed for our sdram configuration

Jerry Walden
Program Manager
Digital Atlantic Inc
http://www.digitalatlantic.com
jwalden at digitalatlantic.com
1-877-494-6073
cell - 703-431-2413

-----Original Message-----
From: Chris Hallinan [mailto:clh at net1plus.com]
Sent: Tuesday, February 11, 2003 10:21 AM
To: jwalden at digitalatlantic.com
Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?


Send me the code and I'll have a quick look.  I know the 405 pretty
well...

> -----Original Message-----
> From: Jerry Walden [mailto:jwalden at digitalatlantic.com]
> Sent: Tuesday, February 11, 2003 10:13 AM
> To: Chris Hallinan
> Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?
>
>
> Thanks for sending the invoice.
>
> The project is tedious at best - I get through the code
> in board_init_f, and
> when (I assume) that routine returns - it returns to a
> procedure that got
> copied over in relocate_code.  I assume the procedure is
> board_init_r.
>
> I get an exception 0x700 after I continue from
> board_init_f, and I can only
> assume that I still do not have my SDRAM configured
> properly, however I've
> got two hardware guys here from a contract shop (Eden
> Networks) who know the
> PPC pretty well, and have done several projects with it,
> and they swear up
> and
> down that my code is configuring the SDRAM properly.
>
> So I'm pretty much stuck - not sure what to try next.
>
> Thanks
>
> Jerry Walden
> Program Manager
> Digital Atlantic Inc
> http://www.digitalatlantic.com
> jwalden at digitalatlantic.com
> 1-877-494-6073
> cell - 703-431-2413
>
> -----Original Message-----
> From: Chris Hallinan [mailto:clh at net1plus.com]
> Sent: Tuesday, February 11, 2003 10:07 AM
> To: jwalden at digitalatlantic.com
> Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?
>
>
> Will do.  How is the project going?
>
>
> > -----Original Message-----
> > From: Jerry Walden [mailto:jwalden at digitalatlantic.com]
> > Sent: Tuesday, February 11, 2003 10:02 AM
> > To: Chris Hallinan
> > Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?
> >
> >
> > Please mail it to the address on the PO - my cpa, atty,
> > etc are all there
> > and that is where my company is based.
> >
> > Thanks Much!
> >
> > Jerry Walden
> > Program Manager
> > Digital Atlantic Inc
> > http://www.digitalatlantic.com
> > jwalden at digitalatlantic.com
> > 1-877-494-6073
> > cell - 703-431-2413
> >
> > -----Original Message-----
> > From: Chris Hallinan [mailto:clh at net1plus.com]
> > Sent: Tuesday, February 11, 2003 9:46 AM
> > To: jwalden at digitalatlantic.com
> > Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?
> >
> >
> > I'll generate an invoice, where should I mail it?  Your
> > PO has a CA
> > address, but you're in VA, right?
> >
> > In the meantime, feel free to ask Q's...I'll help as
> time permits.
> >
> > -Chris
> >
> > > -----Original Message-----
> > > From: Jerry Walden [mailto:jwalden at digitalatlantic.com]
> > > Sent: Monday, February 10, 2003 4:58 PM
> > > To: Chris Hallinan
> > > Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?
> > >
> > >
> > > Thanks for the response Chris -
> > >
> > > I just spoke with my CPA, and we crossed wires re.
> > > the $750 owed to DS4 by Rebound Systems - he was
> > > asking for an invoice - would that be difficult for
> > > you to generate?
> > >
> > > The project is inching along because I just can't seem
> > > to make sense of u-boot - in the "stack loop" whilst building
> > > the stack, I still get a 0x700 exception - I've been working
> > > hard with the hardware guys, and they were the ones that
> > > thought the
> > > problem was that I was using CS 4 (we do not use that) so
> > > I went with
> > > that assumption for a while until I received your responses.
> > >
> > > Thanks!
> > >
> > > Jerry Walden
> > > Program Manager
> > > Digital Atlantic Inc
> > > http://www.digitalatlantic.com
> > > jwalden at digitalatlantic.com
> > > 1-877-494-6073
> > > cell - 703-431-2413
> > >
> > > -----Original Message-----
> > > From: Chris Hallinan [mailto:clh at net1plus.com]
> > > Sent: Monday, February 10, 2003 4:02 PM
> > > To: jwalden at digitalatlantic.com
> > > Subject: RE: [U-Boot-Users] Memory Bank x (nothingness)?
> > >
> > >
> > > It's fake memory (not backed by any physical ram, so it really
> > > doesn't matter what Chip Select it uses,) because the
> > trick is to
> > > use the Data Cache as initial ram for a very small stack
> > > and global
> > > data area.  It flushes the cache, then reads the range, which
> > > basically "caches" the memory range in use.  From then on, all
> > > accesses to this RAM range are satisfied from the
> physical cache
> > > memory, and not the physical memory (which at this
> point in the
> > > startup, is not functional because the initdram()
> > hasn't yet been
> > > done.  It's actually a pretty clever little trick!
> > >
> > > How is the project going?
> > >
> > > When can I expect payment for the PO you issued?  I have a new
> > > address:
> > > 114 Putnam Hill Road
> > > Sutton, MA  01590
> > >
> > > Thanks,
> > >
> > > -Chris Hallinan
> > >
> > > > -----Original Message-----
> > > > From: u-boot-users-admin at lists.sourceforge.net
> > > > [mailto:u-boot-users-admin at lists.sourceforge.net]On
> > > > Behalf Of Jerry
> > > > Walden
> > > > Sent: Monday, February 10, 2003 2:26 PM
> > > > To: u-boot-users at lists.sourceforge.net
> > > > Subject: [U-Boot-Users] Memory Bank x (nothingness)?
> > > >
> > > >
> > > > Greetings -
> > > >
> > > > I have a custom PPC405GPr board, and I am trying to bring
> > > > u-boot up on it.
> > > >
> > > >
> > > > /*--------------------------------------------------------
> > > > ---------------
> > > > */
> > > > 	/* Setup temporary stack in DCACHE or OCM if needed
> > > > for SDRAM SPD. */
> > > >
> > > > /*--------------------------------------------------------
> > > > ---------------
> > > > */
> > > >
> > > > /*--------------------------------------------------------
> > > > ---------------
> > > > */
> > > > 	/* Memory Bank x (nothingness)
> initialization 1GB+64MEG */
> > > > 	/* used as temporary stack pointer for stage0  */
> > > >
> > > > /*--------------------------------------------------------
> > > > ---------------
> > > > */
> > > > 	li	r4,PBxAP
> > > > 	mtdcr	ebccfga,r4
> > > > 	lis	r4,0x0380
> > > > 	ori	r4,r4,0x0480
> > > > 	mtdcr	ebccfgd,r4
> > > >
> > > > The Walnut config has CFG_INIT_DCACHE_INIT_CS = 4
> > > >
> > > > In our custom board do not have anything attached
> to bank 4 -
> > > >
> > > > Does DCACHE for the processors cache or programmers
> > private use?
> > > > How can I (or how should I) re-write/add/subtract the
> > > > above code to
> > > > accomplish
> > > > what it is trying to do (which is not clear to me).
> > > >
> > > > Thanks
> > > >
> > > > Jerry Walden
> > > >
> > > >
> > > >
> > > > -------------------------------------------------------
> > > > This SF.NET email is sponsored by:
> > > > SourceForge Enterprise Edition + IBM + LinuxWorld =
> > > > Something 2 See!
> > > > http://www.vasoftware.com
> > > > _______________________________________________
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> > > > U-Boot-Users at lists.sourceforge.net
> > > > https://lists.sourceforge.net/lists/listinfo/u-boot-users
> > > >
> > >
> > >
> > >
> > >
> >
> >
> >
> >
>
>
>
>

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