Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759993Ab3ICLVl (ORCPT ); Tue, 3 Sep 2013 07:21:41 -0400 Received: from top.free-electrons.com ([176.31.233.9]:36992 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759979Ab3ICLVj (ORCPT ); Tue, 3 Sep 2013 07:21:39 -0400 Date: Tue, 3 Sep 2013 13:21:36 +0200 From: Maxime Ripard To: oliver+list@schinagl.nl Cc: arnd@arndb.de, gregkh@linuxfoundation.org, linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, andy.shevchenko@gmail.com, tomasz.figa@gmail.com, linux-sunxi@googlegroups.com, Oliver Schinagl Subject: Re: [PATCHv7 1/2] ARM: sunxi: Initial support for Allwinner's Security ID fuses Message-ID: <20130903112136.GC2630@lukather> References: <1378204408-1415-1-git-send-email-oliver+list@schinagl.nl> <1378204408-1415-2-git-send-email-oliver+list@schinagl.nl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bAmEntskrkuBymla" Content-Disposition: inline In-Reply-To: <1378204408-1415-2-git-send-email-oliver+list@schinagl.nl> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2758 Lines: 72 --bAmEntskrkuBymla Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Sep 03, 2013 at 12:33:27PM +0200, oliver+list@schinagl.nl wrote: > From: Oliver Schinagl >=20 > Allwinner has electric fuses (efuse) on their line of chips. This driver > reads those fuses, seeds the kernel entropy and exports them as a sysfs > node. >=20 > These fuses are most likely to be programmed at the factory, encoding > things like Chip ID, some sort of serial number, etc. and appear to be > reasonably unique. > While in theory, these should be writeable by the user, it will probably > be inconvenient to do so. Allwinner recommends that a certain input pin, > labeled 'efuse_vddq', be connected to GND. To write these fuses however, > a 2.5 V programming voltage needs to be applied to this pin. >=20 > Even so, they can still be used to generate a board-unique mac from, > board unique RSA key and seed the kernel RNG. >=20 > On sun7i additional storage is available, this is initially used for an > UEFI BOOT key, Secure JTAG key, HDMI-HDCP key and vendor specific keys. >=20 > Currently supported are the following known chips: > Allwinner sun4i (A10) > Allwinner sun5i (A10s, A13) > Allwinner sun7i (A20) >=20 > Signed-off-by: Oliver Schinagl Acked-by: Maxime Ripard Thanks! Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --bAmEntskrkuBymla Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJSJcZAAAoJEBx+YmzsjxAgfx0P/RVmmpDk2eiogvM7N6D4h9wm B3JJyZkTYpoMNx/Fwqu3npXAIQ1pwgkmq7il3cqDpHaa3X9b1/yXGgEWto1iKtjs lZRmOpDDsxnclxDHfldpJMVrOtU7O8Dg68pINqi9pn0eF91FzvR5eYmtDQSIc1X7 O5oNjRU1o+FMbrI31sObUJYDV9X82srPx9QW5HAEq8kDzlvKNOplfojTgGbkhYxc AbwEbqkQIOPNg8JpwwYxtDSZV5pEotWoXWrugF0a0hjQgE5PVh1koqmFzcBA/G7Z qggKBiCJN4MvcJFwgcd+eSna80kBpr9DRd73eDyiR3cCIjhsZhHWLlgrDixUbIU5 tdD4WeyeFvcgoNFxlIgljRrwX+eY1HkYVEIaYI0CJ1T8eHHFxZBreYspwSu4op5h yi3N/ZZ7S049n4LpV5Xlt0JtpfemBQP42nO11fRHwarOjbQkHTuLLhfvYWpbEbm1 8UbShm+Tl7EvDrAIa/GnNy0jNJYJvOaS2LugnIXBoj8f/MBNI3IZiMKXBexGlmcO cM8+gRDp4vBHSv/7SAZtwZnDUEa4xP4HcDQa45evZuQ3AiJQJ2zNEcSa4NFixqQL pgJUYJVnBFZZKZy8WLkzF3BQGW36wKqlp/icF9Ln6r/nscIl8bramUik3gv9jGLN Q2Xjklq6kX9rIKzKUcU5 =tUKu -----END PGP SIGNATURE----- --bAmEntskrkuBymla-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/