Sender: rich AT phekda DOT freeserve DOT co DOT uk
Message-ID: <3EB54B39.464D11FD@phekda.freeserve.co.uk>
Date: Sun, 04 May 2003 18:17:45 +0100
From: Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.2.23 i586)
X-Accept-Language: de,fr
MIME-Version: 1.0
To: djgpp-workers AT delorie DOT com
Subject: Re: uname and Athlons [PATCH]
References: <E19BwRu-00014b-00 AT phekda DOT freeserve DOT co DOT uk> <034c01c31184$91062480$0600000a AT broadpark DOT no>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Reply-To: djgpp-workers AT delorie DOT com

Hello.

Gisle Vanem wrote:
> 
> "Richard Dawe" <rich AT phekda DOT freeserve DOT co DOT uk> said:
> 
> > + /* What we need is instruction family info in 8-11 bits */
> > + family = (cpuid_info & 0x780) >> 8;
> > + switch (family)
> 
> I dont' get this. Isn't this extracting bits 7-10 (assuming we call the
> LSB bit 0).

No, because the rotate eliminates bits 0-7, leaving us with bits 8-10 in
family at bit positions 0-2.

The bitwise AND eliminates bit 11. This is the extended family bit.

Actually, the above comment & code are bit strange. I did not change them,
when I added the Athlon support. I modified it to store the family in a
variable, rather than just switching on the value.

Perhaps the comment and code should be more like this:

    /* What we need is instruction family info in 8-11 bits.
     * Ignore the extended family bit. */
    family = (cpuid_info & 0x700) >> 8;
    ...

> > +    {
> > +    case 0x7: strcpy(u->machine, "i786"); break;
> > +    case 0x6: strcpy(u->machine, "i686"); break;
> > +    case 0x5: strcpy(u->machine, "i586"); break;
> > +    default:
> > +    case 0x4: strcpy(u->machine, "i486"); break;
> > +    }
> 
> > + if ((family == 0x6) && (strcmp(vendor, "AuthenticAMD") == 0))
> > +    strcpy(u->machine, "athlon");
> 
> Wouldn't this set "athlon" for a "duron" AMD K7 processor too?
> Check bit 7..4 to be sure.

"duron" does not seem to be in list of "machine hardware types" understood by
config.sub. (config.sub constructs triplets like i686-pc-msdosdjgpp.) Perhaps
the chose the name "athlon" for the K7-family, before the Duron was released?

Bye, Rich =]

-- 
Richard Dawe [ http://www.phekda.freeserve.co.uk/richdawe/ ]