Accessing board hardware, also custom logo/splashscreen

[dluberger]

i.mx6ull evk.  I followed the instructions to put Linaro Debian on the board, and everything is up and running. now I have a couple questions. First, hopefully simplest: how do I show a custom splashscreen that just hides everything displayed during boot or at least show my logo instead of the NXP and linux penguin logos during boot? 

Second, I realize there is a device tree, and there is are files and folders in /sys that give me access to the peripherals on the micro, but how in the world do i use them? when i try searching the internet for examples, everything is for the raspberry pi.  i want to read and write comm bytes via uart, i2c, and spi, and read and toggle gpio bits.  All the stuff that the i.mx6 provides as a microcontroller beyond just running linux.

[Bio_TICFSL]

Hi David,

For splash screen is more configuration of debian, you need an external application such as splashImage.

For peripheral usage on linux please check:

UART (Linux) 

[dluberger]

UART I realize isn't really a big deal in linux, so that was a bad example.  I really just want to access the APIs in C for GPIO, etc.  According to the NXP linux manual for i.mx, there should be a drivers folder with a bunch of APIs, but those are nowhere to be found in this Debian build.