[U-Boot] [PATCH 2/5] net: add helper to generate random mac address

[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"

> +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 ?  and if you add a 2nd rand() call, you 
could seed all 48bits easily.

then to make sure the first byte is correct, you finish off with:
	/* make sure it's local and unicast */
	enetaddr[0] = (enetaddr[0] | 0x02) & ~0x01;
-mike
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