On Sat, 5 Mar 2022, Mike Rapoport wrote: > > > For example I have an x86 system that Linux does not how to interrogate > > > for RAM beyond 64MiB, so I do use `memmap=128M@0' (for legacy reasons the > > > x86 platform has a special exception to always exclude area between 640K > > > and 1M from being used even if not explicitly specified, but we do not > > > have a need for such legacy such legacy concerns with the MIPS port). I > > > consider it an interim measure however until the kernel has been fixed. > > > > > > Maciej > > > > > > > Hi Mike, Thomas and Maciej, > > > > Thank you very much for your feedbacks and discussions. > > > > To be frank, I think mem= and memmap= are used for debugging and testing > > in most cases, the intention of this patchset is to refactor the related > > code to make them work well on mips. > > mem= works fine on mips and there is no need to change it. > > If you must supply complex memory layout on the command line, consider > implementing support for memmap=exact and multiple memmap= parameters on > the kernel command line, like x86 does. There's nothing to implement as the MIPS port has supported arbitrary memory maps since Dec 11th, 2000; that's almost 22 years now. C.f.: <https://lore.kernel.org/linux-mips/Pine.GSO.3.96.1000814133957.7256S-100000@xxxxxxxxxxxxxxxxxxx/>, <https://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git/commit/?id=97b7ae4257ef>. Sadly commit a09fc446fb6d ("[MIPS] setup.c: use early_param() for early command line parsing") removed last pieces of inline documentation; I don't know why things like that get approved, but neither I can take responsibility. Also to say (in said commit): "There's no point to rewrite some logic to parse command line to pass initrd parameters or to declare a user memory area. We could use instead parse_early_param() that does the same thing." is IMHO unfair given that the "rewrite" was there in place almost six years before `parse_early_param' even started to exist! Why do people assume things have always been like they see them at the time they look? Maciej
