[U-Boot] RFC - how to support multipl DRAM chips in a single SPL build?

Wolfgang Denk wd at denx.de
Wed Mar 7 23:13:35 CET 2012

Dear Tom Rini,

In message <CA+M6bXkgRyPFf2iLyiP6rptnkdU3=zG_wCpQhLvcjMDp1Of9PA at mail.gmail.com> you wrote:
> Note that beagleboard handles this today, and the intent is that we
> should be able to support a wide range of choices, with whatever
> method is best on the board.  For example (and hiding from Wolfgang)
> in am335x land, we plan to poke the EEPROM over i2c and see what it
> tells us for a board and pick out based on that.

There should be no need for that.  If the possible configuration
options are know, auto-detection is possible as well.

Given that EEPROM access is pretty slow, auto-detecting might even be
faster.  And it helps detecting memory problems (usually when boards
get booted fresh from production).

> Part of the problem is, for hardware out in the wild, do you have a
> method to determine what rev you're on?  This is where the EEPROM on
> am335x comes in.

You don't need to know the board rev.  All you need to know is the
set of possible config options.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"Nature is very un-American.  Nature never hurries."
- William George Jordan

More information about the U-Boot mailing list