Hi, > On Sep 16, 2023, at 07:17, Henry Wang <henry.w...@arm.com> wrote: > > Hi Julien, > >> On Sep 16, 2023, at 05:41, Julien Grall <jul...@xen.org> wrote: >> >> Hi Henry, >> >> I realize that this was already committed. But something went wrong during >> the code movement. >> >> On 28/08/2023 02:32, Henry Wang wrote: >>> +/* >>> + * Enable mm (turn on the data cache and the MMU) for the boot CPU. >>> + * The function will return to the virtual address provided in LR (e.g. the >>> + * runtime mapping). >>> + * >>> + * Inputs: >>> + * lr : Virtual address to return to. >>> + * >>> + * Clobbers x0 - x5 >>> + */ >>> +ENTRY(enable_boot_cpu_mm) >>> + mov x5, lr >>> + >>> + bl create_page_tables >>> + load_paddr x0, boot_pgtable >>> + >>> + bl enable_mmu >>> + mov lr, x5 >>> + >>> + /* >>> + * The MMU is turned on and we are in the 1:1 mapping. Switch >>> + * to the runtime mapping. >>> + */ >>> + ldr x0, =1f >>> + br x0 >>> +1: >>> + /* >>> + * The 1:1 map may clash with other parts of the Xen virtual memory >>> + * layout. As it is not used anymore, remove it completely to >>> + * avoid having to worry about replacing existing mapping >>> + * afterwards. Function will return to primary_switched. >>> + */ >>> + b remove_identity_mapping >>> + >>> + /* >>> + * Below is supposed to be unreachable code, as "ret" in >>> + * remove_identity_mapping will use the return address in LR in >>> advance. >>> + */ >>> + b fail >> >> The "b fail" didn't exist in head.S. I guess this was due to a wrong >> rebase? Can you check if there is something else that went missing? > > Please correct me if I am wrong but I think the “b fail” of > enable_boot_cpu_mm() is > in the mmu head.S, see line 348 [1]. > > [1] > https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/arm/arm64/mmu/head.S;h=d71fdc69a531780501387fc5c717b4c41bb1b66a;hb=6734327d76be38d20f280ecc96392e385fbc1d8b#l348
Oh I realized we agreed to remove this line as it is unreachable, I will send a patch. Sorry about it. Kind regards, Henry > > Kind regards, > Henry > > >> >> Cheers, >> >> -- >> Julien Grall >
