2.12.3 Enabling TI UIO

First of all, you must enable TI UIO build feature (see TI UIO Support section) and do a complete image Build.

When an image with TI UIO support is built, it is necessary to enable this feature by loading the required devicetree (.dtb) file at startup. To do this, you need to stop booting U-Boot (press any key) when the message Hit any key to stop autoboot is displayed in the serial console and enter following commands:

setenv ti_uio 1
saveenv
boot

When Linux boots with the TI UIO feature enabled, you should see uio* devices in the file:/dev directory:

[root@tanowrt ~]# ls /dev/uio*
/dev/uio0             /dev/uio4             /dev/uio_pruss_0_mem
/dev/uio1             /dev/uio5             /dev/uio_pruss_1_mem
/dev/uio2             /dev/uio6             /dev/uio_pruss_mem
/dev/uio3             /dev/uio7             /dev/uio_pruss_mem2

If you later want to boot without the TI UIO feature enabled, you need to set back ti_uio environment variable to 0. To do this, run the following commands in U-Boot prompt:

setenv ti_uio 0
saveenv

or in the Linux terminal:

fw_setenv ti_uio 0

and reboot board.