On 10/14/2016 03:04 PM, [email protected] wrote: > On October 14, 2016 11:44:18 AM PDT, Boris Ostrovsky > <[email protected]> wrote: >> On 10/14/2016 02:31 PM, [email protected] wrote: >>> On October 14, 2016 11:05:12 AM PDT, Boris Ostrovsky >> <[email protected]> wrote: >>>> From: Matt Fleming <[email protected]> >>>> >>>> The new Xen PVH entry point requires page tables to be setup by the >>>> kernel since it is entered with paging disabled. >>>> >>>> Pull the common code out of head_32.S and into pgtable_32.S so that >>>> setup_pgtable_32 can be invoked from both the new Xen entry point >> and >>>> the existing startup_32 code. >>>> >>> And why does it need a separate entry point as opposed to the plain >> one? >> >> One reason is that we need to prepare boot_params before jumping to >> startup_{32|64}. >> >> When the guest is loaded (always in 32-bit mode) the only thing we have >> is a pointer to Xen-specific datastructure. The early PVH code will >> prepare zeropage based on that structure and then jump to regular >> startup_*() code. >> >> -boris > And why not just resume execution at start_32 then?
I am not sure what start_32 is. If you meant startup_32 then that's exactly what we do (for 32-bit guests) once zeropage is set up. -boris -boris
