[U-Boot-Users] using BDI200 to access RAM

[Wolfgang Denk]

In message <OF35478C15.8439F998-ONC2256EA7.004A3D27-88256EA7.004B09F2 at mksinst.com> you wrote:
> 
> I work with custom board based on MPC850.
> This board has 8MB  flash on address 0xff800000
> I try to access (get/set) memory using BDI2000 telnet API (MD/MM)
> Unfortunately all memory I can see is the flash. It appears on address 0 
> (MD 0) and returns every 8MB.
> Command PHYS 0 (map physical address) returns 0.

You must initialize the memory corntoller for the RAM, i. e.  program
the BRx/ORx registers, set up the UPM engine and run the SDRAM's init
sequence (whatever this requires for your SDRAM chips).

> How can I access DRAM using BDI telnet API?

Sure. If the memory controller was set up correctly.

Examples can be find in most BDI2000 config files (both  those  which
come with the BDI and those on our FTP server), but don't expect that
a  simple copy & paste would work. You really need to understand what
you're doing. Setting up the SDRAM is the most complicated task  when
porting  to  new hardware (at least judging from the number of people
who run into truble with this).

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
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