APEI allows to report errors (for example from the chipset) to the operating system. This improves NMI handling especially. In addition it supports error serialization and error injection.
Generic Hardware Error Source provides a way to report platform hardware errors (such as that from chipset). It works in so called "Firmware First" mode, that is, hardware errors are reported to firmware firstly, then reported to Linux by firmware. This way, some non-standard hardware error registers or non-standard hardware link can be checked by firmware to produce more valuable hardware error information for Linux.
PCIe AER errors may be reported via APEI firmware first mode. Turn on this option to enable the corresponding support.
Memory errors may be reported via APEI firmware first mode. Turn on this option to enable the memory recovering support.
EINJ provides a hardware error injection mechanism, it is mainly used for debugging and testing the other parts of APEI and some other RAS features.
ERST is a way provided by APEI to save and retrieve hardware error information to and from a persistent store. Enable this if you want to debugging and testing the ERST kernel support and firmware implementation.