On 15.12.21 13:24, Krystian Hebel wrote: > Hi Nico, > > On 15.12.2021 12:21, Nico Huber wrote: >> Hi Krystian, >> >> On 14.12.21 13:00, Krystian Hebel wrote: >>> For our work on POWER9 coreboot port we were using Skiboot [1] packed >>> into >>> FIT payload. >> I might just miss it because I never worked with FIT, but maybe I'm not >> the only one: Can you elaborate why you chose FIT? Reading through your >> mail (and without further knowledge) it would just seem like the wrong >> choice. > > Good point, I spent so much time in this project that I treat too many > things as obvious. Don't hesitate to ask if I omit something important. > > Skiboot must be supplied with information about hardware. Some of that > is generated by code based on current configuration (e.g. number of > cores, their IDs, memory amount and associativity), but a lot is always > the same for a given platform or even whole architecture (BMC sensors, > interrupt controller, register address space, LPC controller).
Isn't this all or mostly information that coreboot has already available? It seems much like the situation on x86 with ACPI. We also had static ACPI tables that redundantly stored infor- mation at first. However, static ACPI tables were never treated first-class, sometimes even like an alien, and were prone to rot. Today, we try a good compromise between runtime generation and static tables (which can be extended at runtime). > This can > be passed either in HDAT structure (Hostboot data, proprietary and > mostly undocumented format in supposedly open firmware) or, as we > learned after asking on OpenPower-Firmware mailing list, using FDT: > > https://lists.ozlabs.org/pipermail/openpower-firmware/2021-May/000641.html > > In our current setup that second, constant part is supplied as FDT in > FIT image so it can be added as .dts file, which is easier to read and > understand than C code that would be used for creating these nodes. Hmmm, I read above mailinglist thread. But I still miss the link to FIT. coreboot would have a dtb (doesn't matter if it generates it at runtime or a file in CBFS) and a payload (in CBFS or some other flash partition), right? Why do you need FIT? Nico _______________________________________________ coreboot mailing list -- coreboot@coreboot.org To unsubscribe send an email to coreboot-le...@coreboot.org
