Why does Intel® Arria® SoC HPS fail to boot from SD card in MBR partition mode on warm reset when the first bootloader image is corrupted?

Due to a problem in the Intel® Arria® 10 SoC HPS BootROM, the HPS fails to boot on warm reset when all of the following conditions are met:

• BSEL is configured for SD/MMC
• SD/MMC is used in MBR partition mode
• The first bootloader image (located at offset 0 in the A2 partition) is corrupted

The issue can be worked around by duplicating the 512-byte MBR structure located at the beginning of the SD card at the following SD card addresses:

• 0x40000 (256KB)
• 0x80000 (512KB)
• 0xC0000 (768KB)

In a typical system, the areas where the MBR needs to be duplicated are not used. However, your particular system may use those areas for some purpose. Make sure to verify there is nothing else on that location on the SD card before duplicating the MBR structure.