how to stop BIOS reseting when powering off

alexis_nicolas

I have a UP 4000, and I had to change the direction of GPIO19 (pin16) to "output" for the SPI clock signal to be working. The problem is that each time power comes out of the board, meaning when I remove the power cord, not a simple shutdown, the BIOS setting is reseted and I have to manually go into the BIOS again to change the pin to "output".

the question already have been asked here : https://forum.up-community.org/discussion/5191/problem-with-bios-for-spi-clock#latest.
but the BIOS provided made the I2C and SPI protocols stop working, reverting to the bios UPAPBM11 worked to get them working again, but I still have the BIOS problem.

So is there a working BIOS that can fix this problem, or a way to put the pin to output with code and not going into the BIOS?
I have to send the board in the sky, so I can't manually do it when it will be deployed, and since there is a possibility that the power come off and come back, I need to make the SPI working again.

HarryChiu

Hi Sir

1. Please update the latest bios UPAPBM12.
   After update, the bus number of i2c will be changed by OS.
   It needs to check with the physical path PCI0.I2C0 & PCI0.I2C1.

You can find the path in the respective i2c devices to confirm the physical address.
/sys/bus/i2c/devices/i2c-X/firmware_node/path

2. Please download the latest pinctrl to use SPI function.
   https://github.com/up-division/pinctrl-upboard/releases/tag/v1.1.2

Best Regards,
Harry Chiu