[coreboot] what should CONFIG_HT_CHAIN_UNITID_BASE be in "CPU/1HT device" mode?

Bao, Zheng Zheng.Bao at amd.com
Tue Nov 17 04:28:14 CET 2009


The Agesa code goes the branch of Manual BUID assignment. The swap list
is,
{0x0, 0x0, 0xFF, 0x0, 0xFF}. I made a swaplist manually and the ht link
was set up correctly. Now the problem is,
1. If I let AMD_CB_ManualBUIDSwapList give the swap list, it will
provide
   {0xFF, CONFIG_HT_CHAIN_UNITID_BASE, CONFIG_HT_CHAIN_END_UNITID_BASE,
0xFF}
   It seems that the list is far from we expect.
2. What is the meaning of each entry in the swaplist?

Zheng

-----Original Message-----
From: Myles Watson [mailto:mylesgw at gmail.com] 
Sent: Thursday, November 05, 2009 6:46 AM
To: 'Marc Jones'
Cc: Bao, Zheng; coreboot at coreboot.org
Subject: RE: [coreboot] what should CONFIG_HT_CHAIN_UNITID_BASE be in
"CPU/1HT device" mode?

> There is just the CPU and 690 or 780. The AMD 600 or 700 is connect
> with Alink, not HT.
You're right.  I didn't look closely enough.

> > early_ht.c: Just enumerate the southbridge chain in case that's
needed
> for
> > serial initialization or ROM access.
> >
> > incoherent_ht.c: Enumerate all chains so that they can be optimized
> before
> > the first reset.
> >
> > hypertransport.c: Enumerate the chains according to the device tree.
> 
> Is early_ht.c, enumerate_ht_chain(), even needed. The subtractive path
> should work. Maybe depends on the southbridge/configuration.
For K8, early_ht.c doesn't even get compiled in if you set
CONFIG_HT_CHAIN_UNITID_BASE to 0.

It's needed for the case where there is a tunnel, then the southbridge.
Serengeti Cheetah is a good example.  You can't get to the southbridge
until
you've moved the 8131 or 8132 out of the way.

> For Fam10, I think that where problems happen is the early_ht.c sets
> values that are found and used by the AGESA based code that has a
> slightly different search algorithm. This happens in ht3init.c,
> process_link(). Failures in process_link() cause the system to halt
> even if it could continue based on the early setup.
I wish I knew more about Fam10, but I don't have a board, so I haven't
been
that motivated to look into it further.

Thanks,
Myles








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