I have a Banana PI P2 Zero. I am using the MOSI SPI (gpio 18) to control a ws281x led strip. It works well, when booting from the SD card, but as soon as I burn my image to emmc and remove the SD card, the board boots up with no /dev/spidev0.0 device. I have been unable to figure out the reason.
I thought maybe using the EMMC card (since it is tied to some of the SPI0 pins) would cause this, but I am able to boot using the SD card and mount the EMMC images and use them, and yet I still have control over the SPI MOSI pin to control the LED strip.
Does anyone know of a solution to get the SPI MOSI pin to work when booting from EMMC? Does anyone know the reason for this?