svn commit: r305354 - head/sys/arm/allwinner

[Oliver Pinter]

Hi!

On 9/3/16, Jared McNeill <jmcneill at freebsd.org> wrote:
> Author: jmcneill
> Date: Sat Sep  3 15:28:09 2016
> New Revision: 305354
> URL: https://svnweb.freebsd.org/changeset/base/305354
>
> Log:
>   Use the root key in the Security ID EFUSE (when valid) to generate a
>   MAC address instead of creating a random one each boot.

Could you please describe a little more about this root key? What is
it? What's the main purpose? Is is a crypto root key?

>
> Modified:
>   head/sys/arm/allwinner/if_awg.c
>
> Modified: head/sys/arm/allwinner/if_awg.c
> ==============================================================================
> --- head/sys/arm/allwinner/if_awg.c	Sat Sep  3 15:26:28 2016	(r305353)
> +++ head/sys/arm/allwinner/if_awg.c	Sat Sep  3 15:28:09 2016	(r305354)
> @@ -62,6 +62,7 @@ __FBSDID("$FreeBSD$");
>  #include <dev/ofw/ofw_bus_subr.h>
>
>  #include <arm/allwinner/if_awgreg.h>
> +#include <arm/allwinner/aw_sid.h>
>  #include <dev/mii/mii.h>
>  #include <dev/mii/miivar.h>
>
> @@ -1277,6 +1278,7 @@ awg_get_eaddr(device_t dev, uint8_t *ead
>  {
>  	struct awg_softc *sc;
>  	uint32_t maclo, machi, rnd;
> +	u_char rootkey[16];
>
>  	sc = device_get_softc(dev);
>
> @@ -1285,9 +1287,19 @@ awg_get_eaddr(device_t dev, uint8_t *ead
>
>  	if (maclo == 0xffffffff && machi == 0xffff) {
>  		/* MAC address in hardware is invalid, create one */
> -		rnd = arc4random();
> -		maclo = 0x00f2 | (rnd & 0xffff0000);
> -		machi = rnd & 0xffff;
> +		if (aw_sid_get_rootkey(rootkey) == 0 &&
> +		    (rootkey[3] | rootkey[12] | rootkey[13] | rootkey[14] |
> +		     rootkey[15]) != 0) {
> +			/* MAC address is derived from the root key in SID */
> +			maclo = (rootkey[13] << 24) | (rootkey[12] << 16) |
> +				(rootkey[3] << 8) | 0x02;
> +			machi = (rootkey[15] << 8) | rootkey[14];
> +		} else {
> +			/* Create one */
> +			rnd = arc4random();
> +			maclo = 0x00f2 | (rnd & 0xffff0000);
> +			machi = rnd & 0xffff;
> +		}
>  	}
>
>  	eaddr[0] = maclo & 0xff;
> _______________________________________________
> svn-src-head at freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/svn-src-head
> To unsubscribe, send any mail to "svn-src-head-unsubscribe at freebsd.org"
>