[U-Boot-Users] [PATCH] lpd7a40x register defs, include consolidation

Wolfgang Denk wd at denx.de
Mon Oct 11 19:45:40 CEST 2004


Dear Paul,

in message <200410111119.07866.pruhland at microwavedata.com> you wrote:
> 
> I had code to autodetect the ram working but I removed it since it required 
> changes to several files relating to how the DRAM config is handled (printed, 
> passed to kernel, etc).

OK.

> For configurations with more than 32MB of DRAM the layout is not contiguous, 
> ie. more than one bank is required.  Since the number of DRAM banks is 
> #defined there is no way to adjust this at runtime.  The result is having an 
> extra bank of zero size configured for boards with <= 32MB DRAM.

And this cannot be fixed?

> This gives the wrong impression...that there are more DRAM banks but for some 
> reason one is zero size (ie. something is wrong).

I don't understand. You tell me, that there is no SDRAM populated  on
one  of  the  banks,  resulting  in a smaller total RAM size, and you
hesitate to show this information to the user?

> It would be nice if either:
> 1) the number of DRAM banks was configurable at runtime.

Personally, I don't see any need to display the number  of  banks  at
all;  on PowerPC systems we just print the total RAM size, and every-
body is happy with this.

But no matter what you want - both methods can be  implemented.  Feel
free to submit a patch.

> 2) leave the number of DRAM banks #defined (as max. banks) and simply add 
> checks for zero size in the config print, kernel atag, etc. handling to skip 
> such banks.

Why skip them? What's wrong that a bank that is not  populated  shows
up with a zero size?

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd at denx.de
"Life, loathe it or ignore it, you can't like it."
- Marvin the paranoid android




More information about the U-Boot mailing list