Re: [Xen-devel] Bare-metal Xen on ARM boot

[Sander Bogaert <sander.bogaert@xxxxxxxxx>]

On 29 April 2013 15:48, Sander Bogaert <sander.bogaert@xxxxxxxxx> wrote:
> On 29 April 2013 14:56, Stefano Stabellini
> <stefano.stabellini@xxxxxxxxxxxxx> wrote:
>> On Mon, 29 Apr 2013, Ian Campbell wrote:
>>> On Sun, 2013-04-28 at 15:04 +0100, Stefano Stabellini wrote:
>>> > On Fri, 26 Apr 2013, Sander Bogaert wrote:
>>> > > >> I was getting the number from xen/arch/arm/traps.c:706 ''call =
>>> > > >> arm_hypercall_table[regs->r12].fn;" and the arm_hypercall_table in 
>>> > > >> the
>>> > > >> same file. It should have been #4 by that reasoning I know.
>>> > > >
>>> > > > That macro is such that the fact that something appears at position N 
>>> > > > In
>>> > > > the list doesn't mean it is position N in the resulting array, it
>>> > > > expands into the syntax
>>> > > > array[] = {
>>> > > >         [1] = a_thing
>>> > > >         [4] = another_thing
>>> > > > }
>>> > > > which initialises slots 1 and 4.
>>> > >
>>> > > Thanks, I overlooked that.
>>> > >
>>> > > >>
>>> > > >> Also, I was trying an ELF file. I will try again tomorrow with a
>>> > > >> zImage header and report back.
>>> > > >>
>>> > > >> Thanks,
>>> > > >> Sander
>>> > > >
>>> > > >
>>> > >
>>> > > ELF does seem to be supported but then it gets stuck further down in
>>> > > domain builder code ( I also attached the entire output) :
>>> > >
>>> > > domainbuilder: detail: xc_dom_parse_elf_kernel: xen-3.0-unknown:
>>> > > 0x80000000 -> 0x80010010
>>> > > xc: error: panic: xc_dom_core.c:608: xc_dom_find_arch_hooks: not found
>>> > > (type xen-3.0-unknown): Invalid kernel
>>> > > xc: error: panic: xc_dom_core.c:763: xc_dom_mem_init: arch hooks not
>>> > > set: Internal error
>>> > > libxl: error: libxl_dom.c:384:libxl__build_pv: xc_dom_mem_init failed:
>>> > > No such file or directory
>>> > >
>>> > > The vmlinux binary ( elf ) doesn't boot neither and has the same
>>> > > problem. Could it have something to do with:
>>> > > "xc: detail: elf_xen_note_check: Not bothering with notes on ARM"
>>> > > Missing metadata?
>>> > >
>>> > > I'll focus on getting an zImage working.
>>> >
>>> > The problem seems to be that dom->guest_type is set to
>>> > "xen-3.0-unknown" by xc_dom_guest_type at the end of
>>> > xc_dom_parse_elf_kernel.
>>> > In order to match the ARMv7 supported guest_type it should have been
>>> > "xen-3.0-armv7l", as you can see from
>>> > xc_dom_armzimageloader.c:xc_dom_parse_zimage_kernel.
>>> >
>>> > Maybe we just need to add the appropriate case in the switch in
>>> > xc_dom_guest_type (see below)?
>>>
>>> We certainly need to add something there, and your string seems as
>>> plausible as the next one ;-)
>>>
>>> I suppose we need to handle EM_AARCH64 at some point too...
>>>
>>> I reckon a warning print under the default case would have us then and
>>> other porters in the future...
>>>
>>> >
>>> > diff --git a/tools/libxc/xc_dom_elfloader.c 
>>> > b/tools/libxc/xc_dom_elfloader.c
>>> > index 6583859..911f316 100644
>>> > --- a/tools/libxc/xc_dom_elfloader.c
>>> > +++ b/tools/libxc/xc_dom_elfloader.c
>>> > @@ -74,6 +74,8 @@ static char *xc_dom_guest_type(struct xc_dom_image *dom,
>>> >          }
>>> >      case EM_X86_64:
>>> >          return "xen-3.0-x86_64";
>>> > +    case EM_ARM:
>>> > +        return "xen-3.0-armv7l";
>>> >      default:
>>> >          return "xen-3.0-unknown";
>>> >      }
>>
>> Sander,
>> if you confirm that this change solved your problem, I'll resend as a
>> proper patch.
>
> Hi,
>
> This patch got me further in booting the domain but still got stuck. I
> was adding extra print's to find out where exactly. Here is the
> stacktrace ( attached the whole output too) :
>
> domainbuilder: detail: xc_dom_build_image: called
> domainbuilder: detail: xc_dom_alloc_segment:   kernel       :
> 0x80000000 -> 0x80011000  (pfn 0x80000 + 0x11 pages)
> domainbuilder: detail: xc_dom_pfn_to_ptr: pfn 80000 out of range
> (0x80000 > 0x2000)
> libxl: error: libxl_dom.c:392:libxl__build_pv: xc_dom_build_image
> failed: No such file or directory
> domainbuilder: detail: xc_dom_release: called
> libxl: error: libxl_create.c:908:domcreate_rebuild_done: cannot
> (re-)build domain: -3
> libxl: debug: libxl_event.c:1569:libxl__ao_complete: ao 0x3aa28: complete, 
> rc=-3
> libxl: debug: libxl_create.c:1249:do_domain_create: ao 0x3aa28:
> inprogress: poller=0x34880, flags=ic
> libxl: debug: libxl_event.c:1541:libxl__ao__destroy: ao 0x3aa28: destroy
>
> It ends up in libxl_dom.c:392:libxl__build_pv: xc_dom_build_image
> failed where there is some x86 specific stuff I think.
>
> Thx

Hi,

I was wondering if you had any chance to have a look at this? Would it
be a big patch to make ELF work? I'm trying to figure it out myself
but it's not that easy, I'm new to this :-) ( and I had some problems
compiling the tools again ). Maybe some pointers could help me create
this patch myself?

Sander

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel