On Tue, Sep 03, 2013 at 12:33:27PM +0200, oliver+list@schinagl.nl wrote: > From: Oliver Schinagl > > 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. > > 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. > > Even so, they can still be used to generate a board-unique mac from, > board unique RSA key and seed the kernel RNG. > > 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. > > Currently supported are the following known chips: > Allwinner sun4i (A10) > Allwinner sun5i (A10s, A13) > Allwinner sun7i (A20) > > Signed-off-by: Oliver Schinagl Acked-by: Maxime Ripard Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com