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From: Michael Walle <michael@walle.cc>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/5] net: add helper to generate random mac address
Date: Sun, 1 Apr 2012 22:00:42 +0200	[thread overview]
Message-ID: <201204012200.42962.michael@walle.cc> (raw)
In-Reply-To: <201204011534.27331.vapier@gentoo.org>

Hi Mike,

Am Sonntag 01 April 2012, 21:34:26 schrieb Mike Frysinger:
> On Saturday 31 March 2012 08:38:33 Michael Walle wrote:
> > --- a/include/net.h
> > +++ b/include/net.h
> > 
> > in emergency cases, where you need a working network connection to seti
> 
> "seti" -> "set"
> 
> > + *    Eg. you wan't a rescue boot and don't have a serial port to access
> 
> "wan't" -> "want"
thanks ;)

> > +void eth_random_enetaddr(uchar *enetaddr)
> > +{
> > +	uint32_t rval;
> > +
> > +	srand(get_timer(0));
> > +	rval = rand();
> > +
> > +	enetaddr[0] = 0x02;  /* locally administered */
> > +	enetaddr[1] = 0x00;
> > +	enetaddr[2] = 0x00;
> > +	enetaddr[3] = rval & 0xff;
> > +	enetaddr[4] = (rval >> 8) & 0xff;
> > +	enetaddr[5] = (rval >> 16) & 0xff;
> 
> why only extract 24 of the 32bits ?
couldn't find anything about OUIs and locally administered mac addresses, 
therefore i set the OUI to 0. But as this mac generation only applies to 
emergency cases, i guess it is better to have a smaller chance of duplicate 
mac addresses. 

> and if you add a 2nd rand() call, you
> could seed all 48bits easily.
yes, i'll rework that.

-- 
Michael

  reply	other threads:[~2012-04-01 20:00 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-31 12:38 [U-Boot] [PATCH 0/5 v3] Kirkwood: add lschlv2 and lsxhl board support Michael Walle
2012-03-31 12:38 ` [U-Boot] [PATCH 1/5] lib: add rand() function Michael Walle
2012-03-31 12:38 ` [U-Boot] [PATCH 2/5] net: add helper to generate random mac address Michael Walle
2012-04-01 19:34   ` Mike Frysinger
2012-04-01 20:00     ` Michael Walle [this message]
2012-04-02  5:39   ` Prafulla Wadaskar
2012-03-31 12:38 ` [U-Boot] [PATCH 3/5] net: add eth_setenv_enetaddr_by_index() Michael Walle
2012-04-02  5:42   ` Prafulla Wadaskar
2012-03-31 12:38 ` [U-Boot] [PATCH 4/5] Kirkwood: add lschlv2 and lsxhl board support Michael Walle
2012-03-31 12:38 ` [U-Boot] [PATCH 5/5] Kirkwood: automatically build kwb image for lsxl Michael Walle
2012-04-02  5:24 ` [U-Boot] [PATCH 0/5 v3] Kirkwood: add lschlv2 and lsxhl board support Prafulla Wadaskar

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