On Wed, Nov 14, 2018 at 09:54:50AM +0800, Chao Fan wrote: > CONFIG_KEXEC is only needed in this function. > > When searching RSDP, there are three methods in order: > 1. When booting from KEXEC, 'acpi_rsdp' is added to cmdline by KEXEC, > so it can be parsed and used. CONFIG_KEXEC is needed here.
But theoretically acpi_rsdp can be supplied by the first kernel too, right? So you don't need that CONFIG_KEXEC here at all? > >Ok, let's recap: so far, for your use case you need: > > > >CONFIG_MEMORY_HOTREMOVE > >CONFIG_RANDOMIZE_BASE > >and now > >CONFIG_KEXEC > > > >So, you can clean up all that ifdeffery by defining a new config item > >CONFIG_EARLY_PARSE_RSDP or so which depends on all those three items and > >then you can do > > > >vmlinux-objs-$(CONFIG_EARLY_PARSE_RSDP) += $(obj)/acpitb.o > > > >and get rid of the most of the ifdeffery. Regardless of CONFIG_KEXEC - you still need to define a CONFIG_ symbol for your use case. We won't be parsing RSDP early on !MEMORY_HOTREMOVE machines, which is the majority. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.