We recently switched our nor flash part from a Micron n25q128a to a Cypress S25FL127S. While both parts were supported by linux in 2016.4 (via the spi_nor.c interface), only the Micron now works with 2018.3. This is probably due to something recently broken in the newer linux spi_nor.c interface. The cypress part has trouble verifying a "flashcp" command.
We installed custom drivers from Cypress (linux-4.14.0-cy-snor-v18.4.zip) and the patch went in successfully. Now *some* things work in linux (jffs2), but flashcp still broken.
I'm guessing that the Mtd utilities must also be rebuilt/modfied? I cannot find their source code anywhere in the build folder. Are these mtd utilities only distributed in BINARY form from Xilinx? Cypress also included a patch for flash_erase.c (which I cannot find either).. How would one go about changing these petalinux commands?