SUMMARY: CPUTYPE for VIA EPIA M-Series Mini-ITX
Garrett Cooper
youshi10 at u.washington.edu
Fri Mar 16 03:41:56 UTC 2007
Jeffrey Goldberg wrote:
> [mailed, posted and bcc'ed to off list respondents]
>
>
> First let me quote my original query:
>
>> I have one of these
>>
>> CPU: VIA C3 Nehemiah (999.52-MHz 686-class CPU)
>> Origin = "CentaurHauls" Id = 0x691 Stepping = 1
>> Features=0x380b035<FPU,DE,TSC,MSR,MTRR,PGE,CMOV,MMX,FXSR,SSE>
>>
>> http://www.via.com.tw/en/products/mainboards/motherboards.jsp?motherboard_id=81
>>
>>
>> And 6.2-RELEASE p2
>>
>> When I set CPUTYPE=c3 in /etc/make.conf the world seemed to build just
>> fine, but (at least) gcc ended up broken. Most compiling attempts
>> after that ended up with gcc reporting an internal error.
>>
>> Now that I've entered the FreeBSD world and am building everything
>> from source, I would like to take advantage of that by compiling for
>> my system.
>>
>> Does anyone have a similar system? And what CPUTYPE or local tuning
>> do you recommend?
>>
>> A dmesg for the system is available at
>>
>> http://ntp0.goldmark.org/temp/dmesg
>
> I've had two responses telling me that the make.conf defaults are just
> fine, and two (one off list) recommending i686/pentiumpro. One for
> pentiumpro and the other for i686, but as Andreas Rudish helpfully
> pointed out, those two are probably the same thing. No one suggested
> using c3. In fact, cpghost emphatically stated not to use C3 in make.conf
>
> Adbullah Ibn Hamad Al-Marri also helpfully directed me for information
> about safe CFLAGS to
>
> http://gentoo-wiki.com/Safe_Cflags
>
> where the entry for the Via Nehemiah says:
>
> ==============================================================
> Nehemiah (C5XL)/C5P (Via)
>
> CHOST="i686-pc-linux-gnu"
> CFLAGS="-march=i686 -msse -mmmx -O2 -pipe -fomit-frame-pointer"
> CXXFLAGS="${CFLAGS}"
>
> note: The more recent versions of the C3 do support the cmov instruction
> and hence -march=i686. If you must be compatible with all VIA C3
> versions, do not use the settings in this section.
>
> note: it is also possible to use "-march=c3-2". <-- Comment to this: I
> got a problem "compiler can't create executables" with this setting.
>
> note: I had much better luck with -Os than with -O2. The cache on the
> nehemiah chips is really small, so making the executables small helps
> more than anything else.
> ==============================================================
>
> The off list response added
>
>
>> - Setting CPUTYPE to pentium, or pentiumpro both work fine. IIRC,
>> the C3 designation is Linux-specific and doesn't exist for
>> FreeBSD.
>>
>
> If everybody agrees that the c3 designation is unwise to use, then
> probably the distributed
>
> /usr/share/examples/etc/make.conf
>
> The off list responded gave extremely helpful and detailed information
> about trimming the kernel for a similar box. I've already done most of
> what that recommends.
>
> In sum, don't use the c3 specification in /etc/make.conf even though the
> example would suggested otherwise.
>
> Thanks all for your help
>
> -j
Indeed. After reading a mock up of the processor is appears that it's an
Intel 686 clone. See:
<http://www.digit-life.com/articles2/roundupmobo/via-c3-nehemiah.html>
(it's a bit old for an article, so I hope you don't mind the dust :)..).
-Garrett
More information about the freebsd-questions
mailing list