What problem does "HW414700" solve? about hostboot

[dcrowell77]

1. HW414700 describes an early chip bug related to missing some SUE reporting. Prior to Nimbus 2.1 there was a chance of missing errors so with this setting applied it will force a checkstop in those cases.
2. If you search in the code you can see that HW414700 is in a lot of places. It seems to affect more than just regular memory since I see it in some of the other initfiles too. In general it will cause more failures to checkstop versus properly failing with SUE/machinecheck.

Why are you interested in forcing checkstops for these kinds of errors? In general we would want the errors to flow upward into a possibly non-fatal machinecheck/SUE that the OS could handle accordingly. These systems are designed to avoid full system checkstops whenever possible.

[Grubby0624]

Thank you for your answer

1. Nimbus 2.1 will cause the OS to be stuck during the DIMM RAS test, and the system serial port continues to report the error "Memory failure: 0x20000000: reserved kernel page still referenced by 1 users" for several hours. I think this is abnormal and unacceptable from the perspective of use
2. Nimbus 2.2/2.3 does not have this phenomenon. After the DIMM RAS test, the checkstop is triggered and the corresponding DIMM is restarted
   So I guess Nimbus 2.1 also has the bug of missing some SUE reporting. That's why I'm interested in "forcing checkstops for these kinds of errors"

[dcrowell77]

It seems unlikely that DD2.1 has the bug but it went unaddressed. However, that level of part is technically only supported as part of the https://github.com/ibm-op-release/op-build branch. It looks like you are trying to use our most current code level. There are all sorts of other settings that could be incorrect for DD2.1 if you are using master. It is possible that you are missing some other tangentially related behavior that the OS interacts with to properly handle the error. It does seem like the OS knows the memory is bad, which I think means that the initial chip bug was fixed since that was a case of not reporting the error at all (a silent failure).