Is Quad SPI mode supported by PetaLinux?
On u-boot/Linux, Zynq/Zynq MPSoC PS drivers support QUAD mode and the Linux MTD framework in general supports QUAD mode.
However, the Linux/u-boot drivers of the AXI Quad SPI IP do not support QUAD mode. FS-boot generated by PetaLinux does not support QUAD mode.
If you are trying to boot PetaLinux on MicroBlaze using QSPI, Only x1 mode can be used.