I am looking at the Navio2 to plug in to the the pine64 board. https://www.pine64.org/
1 of the buses a copy of the Raspberry Pi (B?) gpio buses.
Apart from the driver/host code will need rebuilding, do you know of any other problems I may have?
I think the Navio2 has all it signals at 3.3v (I can not find a schematic for your board, but that is understandabe) want the Pine64 board wants.
Roger
There would be a hundred of problems 
First, these boards that are “Raspberry Pi compatible” never achieve full compatibility. For example, Raspberry Pi has an AUX SPI bus that Navio2 actively uses for RC IO coprocessor. Judging by the pinout of the PINE64 there is no AUX SPI, so it’s nearly impossible to use Navio2 with it fully.
Second, on the software side. Raspberry Pi is a mature platform with drivers polished so shiny by the devs and the community. No other SBC was able to achieve this level. You’ll definitely stumble upon some bugs in the drivers that would prevent proper work.
there are gpio pins where the spi to the stm32 (It looks wrong I used to use the stmc2, talking to st’s bigger SOCs) I have run spi over GPIO pins before (happy is is not I2C the is hard to do).
on the other bus on the pine64 I am likely be using up to 6 cameras that are SPI and 1 hi res camera, for all round vision, the main problem I have with PI.
I am mainly use the pine64 to play with the 64bit ARM, the Pi is cheap, so may start on the PI then move over to the pine64 at a later point.
Bit-banged SPI would be slow and will not provide proper data exchange rate for the RC IO coprocessor (STM32).
