UEFI RAS events

UEFI CPER events

The UEFI BIOS spec defines Common Platform Error Record (CPER) events for the firmware to report errors from different kinds of hardware.

There are several types of CPER events for different types of hardware:

1. CPU:
   • N.2.4: Processor
2. Memory:
   • N.2.5: Memory error
   • N.2.6: Memory error 2
3. PCI/PCIe:
   • N.2.7: PCI express
   • N.2.8: PCI/PCI-X bus
   • N.2.9: PCI/PCI-X component
4. Firmware:
   • N2.10: Firmware
5. DMA:
   • N2.11: DMA
6. Cache Coherent Interconnect (CCIX):
   • N2.12: CCIX PER log.
7. Compute Express Link
   • N2.13: Compute Express Link (CXL) protocol.
8. Others:
   • N.2.3: Non-standard.

CPER processor error

Defined at `Processor Error Sections <https://uefi.org/specs/UEFI/2.10/Apx_N_Common_Platform_Error_Record.html#processor-error-sections`_.

Currently, UEFI 2.6+ BIOS supports 4 types of processors:

• Generic Processor;
• IA32/X64 processor (x86 architecture);
• IA64 processor (Itanium);
• ARM processor.

Each processor type has a different error event.

It should be noticed that ARM events were added on UEFI version 2.6. Yet, one of the fields there was lacking encoding information. Such encoding info was added on UEFI 2.9A errata.