[OpenBIOS] openbios on nvram on l440gx+

[Steve and Sue]

----- Original Message -----
From: David Christensen <dchrist at home.com>
To: <openbios at elvis.informatik.uni-freiburg.de>
Sent: 12 February 2000 04:14
Subject: RE: [OpenBIOS] openbios on nvram on l440gx+


> Intel usually publishes a BIOS writer's guide for each set of chipsets it
> develops.  These will describe in greater detail how to program the DRAM
> registers based on the type of memory found, but you'll probably need to
> sign an NDA to look at them.

You will certainly need an NDA, but that assumes that Intel are going to let
you have the document in the first place. Where I work we tried to get BIOS
writer's guides for various Intel chips whithout much luck :-(

> your using SDRAM with SPD data then you'll also need to read that EEPROM
> data via I2C or the SMBUS, the memory sizing routine will need that data.

You don't have to read the SPD data to size memory; but it it sure makes the
job more easy. However you need to know how the motherboard selects the SPD
for the different DIMM slots. The DIMM itself usualy has an address of '0'.

> You might also just hard code some values so that you can move past the
> memory sizing to look at some other issues.

You will also have to initialize the SDRAM before you can use it, otherwise
you cannot write and just read junk.


Steve

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