setting max memory to use on Alpha?

[Wilko Bulte]

On Mon, May 05, 2003 at 05:31:56PM -0400, Andrew Gallatin wrote:
> 
> Wilko Bulte writes:
>  > Folks,
>  > 
>  > Shouldn't we set a default to the max phys memory 
>  > FreeBSD can use? Using hw.physmem in the loader I mean.
> 
> It should be done based on the rpb systype in machdep.c
> 
>  > Given that the maximum amount of mem that can safely be
>  > used on all system models appears to be 1G.
>  > 
>  > BTW: my AS4100 is now running with 2G without incidents.
>  > Which is a bit strange as I understood from Drew (tnx btw!)
>  > that only Tsunami boxes can run with 2G and everything else
>  > is limited to 1G? 
>  > 
> 
> I mis-spoke.  I just looked at the mcpcia.c code, and its
> got a 2GB direct map window as well.  So it should be happy.

This one I suppose:

/*
 * Direct-mapped window: 2G at 2G
 */
#define MCPCIA_DIRECT_MAPPED_BASE       (2UL*1024UL*1024UL*1024UL)
#define MCPCIA_DIRECT_MAPPED_SIZE       (2UL*1024UL*1024UL*1024UL)

...

/*
         * Set up window 1 as a 2 GB Direct-mapped window starting at 2GB.
         */
 
        REGVAL(MCPCIA_W1_MASK(sc)) = MCPCIA_WMASK_2G;
        REGVAL(MCPCIA_T1_BASE(sc)) = 0;
        alpha_mb();
        REGVAL(MCPCIA_W1_BASE(sc)) =
                MCPCIA_DIRECT_MAPPED_BASE | MCPCIA_WBASE_EN;
        alpha_mb();
        
OK..

That makes TurboLaser also a 2GB max box.

But I don't quite understand:

pchip_init(volatile tsunami_pchip *pchip, int index)
{
   
        int i;

        /*
         * initialize the direct map DMA windows.
         *
         * leave window 0 untouched; we'll set that up for S/G DMA for
         * isa devices later in the boot process
         *
         * window 1 goes at 2GB and has a length of 1 GB. It maps
         * physical address 0 - 1GB. The SRM console typically sets
         * this window up here.
         */

        pchip->wsba[1].reg = (2UL*1024*1024*1024) | WINDOW_ENABLE;
        pchip->wsm[1].reg  = (1UL*1024*1024*1024 - 1) & 0xfff00000UL;
        pchip->tba[1].reg  = 0;

        /*
         * window 2 goes at 3GB and has a length of 1 GB.  It maps
         * physical address 1GB-2GB.
         */

        pchip->wsba[2].reg = (3UL*1024*1024*1024) | WINDOW_ENABLE;
        pchip->wsm[2].reg  = (1UL*1024*1024*1024 - 1) & 0xfff00000UL;
        pchip->tba[2].reg  = 1UL*1024*1024*1024;

        /*
         * window 3 is disabled.  The SRM console typically leaves it
         * disabled
         */

It appears that Tsunami boxes are 1GB max?

> Also, the UP1000/UP1100/UP1500 irongate machines should be good for as
> much as 4GB of ram, but you can't squeeze that much into the box.

Not enough DIMM slots?

-- 
|   / o / /_  _   		wilko at FreeBSD.org
|/|/ / / /(  (_)  Bulte