[coreboot] Questions about more AMD related flags

Scott Duplichan scott at notabs.org
Sat Nov 6 05:32:05 CET 2010


-----Original Message-----
From: coreboot-bounces at coreboot.org [mailto:coreboot-bounces at coreboot.org] On Behalf Of Patrick Georgi
Sent: Friday, November 05, 2010 02:11 PM
To: coreboot at coreboot.org
Subject: [coreboot] Questions about more AMD related flags

]Hi,
]
]while I opened that can of worms over with QRANK_DIMM_SUPPORT, and
]people are listening ;-), let me widen the debate some more:
]
]SET_NB_CFG_54:
]1. It's used in two places (dualcore and quadcore AMD code)
]2. There, it's set active if undeclared before
]3. All other declarations set this active
]
]Any reason to keep this variable at all? If yes, I'll move it to
]Kconfig, otherwise I'll just drop it.


I am familiar with the recent history of this bit. It defaults to
zero, resulting in the 'weird' local apic id numbering. BIOS is 
supposed to set it early to get the normal apic id numbering. 
While I do not know the origin of this strange bit, I do know
it was scheduled for removal in future AMD processors. Unfortunately
the removal plan was rejected. I would certainly get rid of
SET_NB_CFG_54. Just let coreboot set this bit early so that there
is no need to deal with two different local apic id formats.

Thanks,
Scott


]Thanks,
]Patrick





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