The boundaries are configured during the "sdram_set_registers" phase of setup, but (for E7501) the "sdram_set_spd_registers" phase overrides those values before the RAM commands are sent in the "sdram_enable" phase. There is evidence in the code that this was not always the case.
Steve
-----Original Message----- From: Ronald G. Minnich [mailto:rminnich@lanl.gov] Sent: Tuesday, June 14, 2005 9:25 AM To: Steven J. Magnani Cc: linuxbios@openbios.org Subject: Re: [LinuxBIOS] E7501 SDRAM command bug?
I would need to look at that code more, but what is typically done is the boundary registers are programmed so that the ram "size" is 0x4000000 and all the commands for setup are sent to the ram. Once all the ram init is
done, then the actual row boundaries are set.
We do it this way because it saves a lot of computation that is not really needed.
ron