[BPi-R2] NAND flash instead of eMMC

Hi dear all,

As I had been writing in other thread two of my BPi-R2 boards have defect eMMC chips. It’s not clear yet if chips themselves are bad or there are some other reasons for failure as I don’t currently have any spare BGA153 eMMC chips on hands to attempt replacement and don’t have suitable BGA reball stencil for BGA153/161 to desolder-reball-solder. I had ordered both eMMC chips and stencil from Ali but while waiting for order to arrive I’m thinking about trying to do something else.

From what I see there’s a pad for TSOP-48 chip available at the same spot where eMMC is. Reading marketing docs on MT7623N I can see that SoC is supposed to support NAND flash. For reference board there even was an upstream support for NAND flash controller that had been hidden/removed by this patchset: https://patchwork.kernel.org/patch/10516095/.

It so happened that I’ve got a pile of 1 and 4 GB NAND chips from Intel and Hynix laying around at the bench doing nothing. It makes me wondering if it is possible to get R2 board to work with NAND flash instead of eMMC. Has anyone had any attempts/success to do similar thing by any chance? I’m tempted to have some fun this weekend by giving it a try.