On Thu, Jan 17, 2019 at 3:51 PM Chao Fan <fanc.fnst@xxxxxxxxxxxxxx> wrote: > > On Thu, Jan 17, 2019 at 03:41:13PM +0800, Kairui Song wrote: > >On Wed, Jan 16, 2019 at 5:46 PM Borislav Petkov <bp@xxxxxxxxx> wrote: > >> > >> On Wed, Jan 16, 2019 at 03:08:42PM +0800, Kairui Song wrote: > >> > I didn't see a way to reuse things in that patch series, situation is > >> > different, in that patch it needs to get RSDP in very early boot stage > >> > so it did everything from scratch, in this patch kexec_file_load need > >> > to get RSDP too, but everything is well setup so things are a lot > >> > easier, just read from current boot_prams, efi and fallback to > >> > acpi_find_root_pointer should be good. > >> > >> No no. Early code should find out that venerable RSDP thing once and > >> will save it somewhere for further use. No gazillion parsings of it. > >> Just once and share it with the rest of the code that needs it. > >> > > > >How about we refill the boot_params.acpi_rsdp_addr if it is not valid > >in early code, so it could be used as a reliable RSDP address source? > >That should make things easier. > > I think it's OK. > Try to read it, if get RSDP, use it. > If not, search in EFI/BIOS/... and refill the RSDP to > boot_params.acpi_rsdp_addr. > By the way, I search kernel code, I didn't find other code fill and > use it, only you(KEXEC) are trying to fill it. > If I miss something, please let me know. Yes, kexec would read RSDP again to pass it to second kernel, and only if EFI is disabled (efi=noruntime/old_map, else second kernel will get rsdp just fine). Not sure if any other component would use it. > > Thanks, > Chao Fan > -- Best Regards, Kairui Song _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
