Section 3.3.13 in the Bolt manual describes all the pins but I'm failing to find how I access them from the OS. I wanted to see if I could make the Bolt fit an application where a keyboard is needed and the keyboard matrix in the embedded controller would be great for the purpose. Is there any documentation or help for how to access and use this port? I'm currently running Debian 10 Buster on the Bolt, with Linux 4.19. /sys/class/gpio contains a GPIO devices identified as AMD SB, but I don't know the name of the pins so cannot test if that is what I'm looking for. It doesn't accept any combination of the identifiers in the manual that I've tried. I saw that the chip controlling this header (MEC1705) is connected over SPI directly to the Ryzen CPU but that doesn't help me much.