NetBSD Problem Report #52414
From paul@whooppee.com Mon Jul 17 11:07:03 2017
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Date: Mon, 17 Jul 2017 19:07:00 +0800 (+08)
From: paul@whooppee.com
Reply-To: paul@whooppee.com
To: gnats-bugs@NetBSD.org
Subject: cpuctl(8)/cpuctl(4) shortcomings
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>Number: 52414
>Category: bin
>Synopsis: cpuctl(8)/cpuctl(4) shortcomings
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: bin-bug-people
>State: open
>Class: doc-bug
>Submitter-Id: net
>Arrival-Date: Mon Jul 17 11:10:00 +0000 2017
>Originator: Paul Goyette
>Release: NetBSD 8.99.1
>Organization:
+------------------+--------------------------+----------------------------+
| Paul Goyette | PGP Key fingerprint: | E-mail addresses: |
| (Retired) | FA29 0E3B 35AF E8AE 6651 | paul at whooppee dot com |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd dot org |
+------------------+--------------------------+----------------------------+
>Environment:
System: NetBSD speedy.whooppee.com 8.99.1 NetBSD 8.99.1 (SPEEDY 2017-06-28 12:54:24 UTC) #0: Wed Jun 28 17:26:09 UTC 2017 paul@speedy.whooppee.com:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/SPEEDY amd64
Architecture: x86_64
Machine: amd64
>Description:
(I've marked this as a doc-bug even though there are suggestions for
improving the code itself. Please feel free to recategorize if needed.
Current the cpuctl(8) man-page is very amd centric for the microcode update
function. It specifies an amd-specific default filename and the FILES
section lists only the /libdata/firmware/x86/amd/ directory. It also
provides a download URL for the microcode files only for amd!
It might also be nice for the code to be changed to detect Intel-vs-AMD
characteristic and apply different defaults. (For Intel, the default
file could be /libdata/firmware/x86/intel/FF-MM-SS since the Intel files
as currently distributed are named for the CPU's Family-Model-Stepping.)
It certainly doesn't make sense to have an amd-specific default filename
for non-amd processors. Preferably the code will validate that the file
used is appropriate for the processor in question. Which brings up yet
another shortcoming of the current man-page and/or code: are there any
reasonable DIAGNOSTICS issued if the microcode file is not appropriate
for the processor being updated? And/or is there any iBUG/CAVEAT needed
to warn users that applying an incorrect microcode file might render the
processor unuseable?
Finally, the cpuctl(8) utility apparently uses a pseudo-device cpuctl(4).
Yet there is no man-page for cpuctl(4), so there exists no documentation
on the mechanism for retrieving or updating the information. Since the
cpuctl(4) pseudo-device is included in all kernels by default, it only
seems reasonable to document the device interface.
>How-To-Repeat:
>Fix:
>Unformatted:
(Contact us)
$NetBSD: query-full-pr,v 1.39 2013/11/01 18:47:49 spz Exp $
$NetBSD: gnats_config.sh,v 1.8 2006/05/07 09:23:38 tsutsui Exp $
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