On Wed, Jun 1, 2022 at 05:33 AM, Gerd Hoffmann wrote: > > Hmm. Maybe it's time to tackle the log performance problem for virtual > machines? Create a debug log device with DMA support, so we don't need > a vmexit for every single character we want log?
Of course, that doesn't work for native systems. I don't know how other developers perform debugging (possibly via a serial port), but I developed a library stack similar to this one to help me with GSoC last year ( https://github.com/benjamindoron/edk2/commit/db888a928c1c6fc94f6a7670f3402718c10c01d2 ). It's WIP, modelled after the simple coreboot ringbuffer and is missing tracing facilities. Regardless, having a true complement to PcdStatusCodeUseSerial would often be helpful, I suspect (presently, PcdStatusCodeUseMemory only logs the PI status code for the debug messages). > > How does that relate to coreboot? coreboot has logging-to-memory too. > Not sure what the state is, there have been discussions on the coreboot > list about changing that from a pure text log to something structed with > timestamps a while back. Don't know whenever this did actually happen. > > So, when adding logging-to-memory to edk2 it surely make sense to > coordinate that with coreboot, so we'll have both coreboot and edk2 logs > there in case edk2 runs as coreboot payload. I'm working on getting a SerialPortLib that logs to CBMEM merged. It's on the list at the moment. Some comments on DebugLibBootlog: - It's possible to support ASSERTs. If PcdDebugPropertyMask & 0x31 == 0x01, then non-fatal ASSERTs are logged. As a DebugLib, this would require handling in `DebugAssert()`. - SMM-phase logging can be implemented, but I'm not convinced that sharing DXE's buffer is entirely safe. Using SMM communicate could be safer, but would be more complicated. I stopped working on it when the return-on-investment was too low. Regards, Benjamin -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#90129): https://edk2.groups.io/g/devel/message/90129 Mute This Topic: https://groups.io/mt/91368904/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
