Due to a problem in the SoC EDS software version 15.0.1 and earlier, this error may be seen when compiling a Software Preloader (SPL) targeting Cyclone® V SOC or Arria® V SOC for designs with HPS SDRAM ECC enabled in Qsys.
From 15.0.1, the BSP setting SDRAM_SCRUB_REMAIN_REGION is enabled by default, but SDRAM_SCRUBBING is disabled by default, causing a conflict.
To work around this problem, enable SDRAM_SCRUBBING for your SPL BSP in the advanced section of the BSP-Editor GUI
Then:
1. Re-generate the BSP
2. Re-compile the SPL: Run make clean and make in your generated SPL directory
See the SoC EDS User Guide for more detail on SDRAM_SCRUB_REMAIN_REGION and SDRAM_SCRUBBING