Re: [LinuxBIOS] Clarification of Raminit.c

[roger]

On Sun, 2007-05-13 at 01:39 -0700, roger wrote:
> I'm kind of confused on this one...
>
> How would I specify a DRAMC or CAS setting (after referring to the 440BX
> intel spec pdf)?
>
> For example:
>
> --- Snip from Intel pdf ---
> NBXCFG—NBX Configuration Register (Device 0)
> Offset: 50–53h
> Default: bits 31–16: 0000h
> bits 15–0: 00S0-0000-000S-0S00b
> Access: Read/
> Size: 32 bits
> ...snip...
> Bit
> 13:12  00 = 100 MHz, 11 = Reserved
> --- End Snip from Intel pdf ---
>
> Again, just using this as an example as values should be provided by SPD
> values.  In i440bx/raminit.c, we set this with the following values:
>
> NBXCFG, 0x00000000, 0xff00a00c,
>
> I'm guessing the "0x00000000" & "0xff00a00c" values are calculated by
> somehow adding all the settings possible for NBX and somehow, the value
> is uniquely recognized by the Northbridge??

Looking at the function within raminit.c a comment reveals:

/* Table format: register, bitmask, value. */

So, I presume:

register == NBXCFG ???
bitmask == 0x00000000 ???
value == 0xff00a00c ???

Also presuming these hexadecimal word (32 bit) values were converted
from the original decimal notation.

Sun May 13 02:06:28 PDT 2007