On 21/03/2022 13:32, Florian Fainelli wrote: > [...] > The AON (standing for always-on) is a small domain in the SoC that can > retain its state across various system wide sleep states and specific > reset conditions. The AON DATA RAM is a small ram of a few words (< 1KB) > which can store persistent information across such events. > > The purpose of this write was initially to help with indicating to the > boot loader that a panic occurred and so that it should try its best to > preserve the DRAM contents holding that buffer for recovery by the Linux > kernel as opposed to wiping out DRAM clean again. I cannot go into the > mechanics of what happens publicly unfortunately. > Thanks a lot Florian! This is very good information, it's enough for me - I'd like to be sure it's not rebooting the board or something "extreme" like that, so in the end...it's kinda the opposite, it's preserving the DRAM. >> >> Any information that helps me to document such panic event is very >> welcome, and in case you have AON documentation, it'd be also pretty great! > > Why are you asking specifically about this if I may ask? If you are a > legitimate Broadcom STB customer you can reach out to our support and I > am sure the question will come back for me to answer. Oh I'm not a Broadcom STB customer, I'm just working in the panic notifiers and was curious about this one. When I submit my series (soon) it's likely that there will be a small refactor of this notifier plus a comment, with your great explanation. Regarding the full AON documentation, I just asked in case it's public and I couldn't find - it's unfortunate that a lot of code in the kernel is based on closed specifications, but I understand we can't do much about that. Your response was very useful, and enough for my work =) Cheers, Guilherme _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
