Unable to use csu_config.h to secure GPIO access from normal world

[Stefan Kalkowski]

Hi,

On 06/06/2017 03:57 PM, Abhishek Kumar wrote:
> Hello
> I am using genode trustzone code on imx53 board. AFAIU, following lines
> in csu_config.h are supposed to regulate the access from normal world:
> 
> ```
> namespace Csu_config
> {
>         enum {
>                 SECURE_GPIO  = 1,
>                 SECURE_ESDHC = 0,
>                 SECURE_UART  = 0,
>                 SECURE_I2C   = 1,
>         };
> };
> ```
> 
> Though GPIO is set secure, I am still able to set direction and value of
> gpios from the linux running in normal world, on top of tz_vmm running
> in secure world. Should it not raise some exception? Where am I going
> wrong?

I would assume it to silently ignore your settings, as the GPIO driver's
register access is just uncommented. Have a look here:


https://github.com/skalk/linux/commit/eccce1c595d7962c95086d6fa60291f7c2c1a497#diff-b66779fc74ad745e9385d5107cc44104

Are you sure that GIO settings are really changed?

Regards
Stefan

> 
> Thanks
> Abhishek
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> 
> 
> 
> _______________________________________________
> genode-main mailing list
> genode-main at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/genode-main
>