Xen project Mailing List

On Mon, 2012-07-02 at 14:09 +0100, Shriram Rajagopalan wrote:
> I have a IBM System x3600 series server with UEFI.
> I managed to compile the xen EFI (xen-4.2-unstable.efi).
> The machine is currently running Ubuntu with grub2.
> I can see a grubx64.efi in /boot/efi/EFI/ubuntu/grubx64.efi
> Where should I put the xen efi ?
> I tried creating a efi/EFI/xen/xen-4.2-unstable.efi and added it as a boot option using efibootmgr.
> All I get in that case is a blank screen.
> I had to go into the UEFI bios menu to delete that option in order to boot
> the system via the usual grub.

Not sure if you've seen this but some EFI docs were committed last week,
maybe they help?

http://xenbits.xen.org/docs/unstable/misc/efi.html

Thanks for the pointer Ian!. That answers a bunch of questions.

I still have a couple of questions:

1. EFI_VENDOR

On my machine, I have /boot/efi/EFI/ubuntu/grubx64.efi

Does this mean I should set the EFI_VENDOR to 'EFI/xen' ?

I once tried to simply (dumb!) create the EFI/xen directory and

dropped the xen-4.2-unstable.efi on that folder, added that folder

as one of the EFI boot options, via the efibootmgr program.

2. Config file

The doc says that the binary requires a config file. Should this

config file be placed in the same target folder (i.e. /boot/efi/EFI/xen/xen-4.2-unstable.cfg) ?

"One can override this with a command line option (-cfg=<filename>"

What command is this referring to ?

3. Location of Kernel files

Can they be in their usual /boot/vmlinuz.. location or should they also be placed

in the same folder as the efi ?

Errata:

@jacek:

I have tried booting xen with the usual grub option. I get

"Not enough memory to relocate dom0 kernel". When I searched online, this seemed

to be a bug with RHEL/IBM SystemX machines. However, the fixes pointed to changing

some boot orders, etc which dont apply to my machine IMO.

so, on a limb, I applied a patch from a serverfault.com post (modded to xen-4.2):

http://serverfault.com/questions/342109/xen-only-sees-512mb-of-system-ram-should-be-8gb-uefi-boot

Patch below for reference.

This one allowed me to boot into xen finally, via the grub option. Unfortunately, xen only sees 1 CPU

on a 16-core machine (dual socket). What a bummer. It just says

(XEN) Multiboot-e820 RAM map:

(XEN) 0000000000000000 - 000000000006c000 (usable)

(XEN) 000000000006c000 - 000000000006d000 (ACPI NVS)

(XEN) 000000000006d000 - 000000000009f000 (usable)

(XEN) 000000000009f000 - 00000000000a0000 (ACPI NVS)

(XEN) 0000000000100000 - 000000007c11d000 (usable)

(XEN) 000000007c11d000 - 000000007ec92000 (reserved)

(XEN) 000000007ec92000 - 000000007f7bf000 (ACPI NVS)

(XEN) 000000007f7bf000 - 000000007f7ff000 (ACPI data)

(XEN) 000000007f7ff000 - 000000007f800000 (usable)

(XEN) 0000000080000000 - 0000000090000000 (reserved)

(XEN) 00000000fed1c000 - 00000000fed20000 (reserved)

(XEN) 00000000ff800000 - 0000000100000000 (reserved)

(XEN) 0000000100000000 - 0000001080000000 (usable)

(XEN) ACPI Error (tbxfroot-0218): A valid RSDP was not found [20070126]

===

diff -r c6c9d20963d7 xen/arch/x86/setup.c

--- a/xen/arch/x86/setup.c Tue Jun 26 17:00:20 2012 +0100

+++ b/xen/arch/x86/setup.c Mon Jul 02 02:06:30 2012 -0400

@@ -667,6 +667,7 @@

if ( ((unsigned long)cpu0_stack & (STACK_SIZE-1)) != 0 )

EARLY_FAIL("Misaligned CPU0 stack.\n");

+#if 0

if ( efi_enabled )

{

set_pdx_range(xen_phys_start >> PAGE_SHIFT,

@@ -684,6 +685,7 @@

memmap_type = loader;

}

+ /* disable raw e801 and e820 for now in favor of multiboot provided maps */

else if ( e820_raw_nr != 0 )

{

memmap_type = "Xen-e820";

@@ -699,7 +701,10 @@

e820_raw[1].type = E820_RAM;

e820_raw_nr = 2;

}

- else if ( mbi->flags & MBI_MEMMAP )

+ else

+#endif

+ if ( mbi->flags & MBI_MEMMAP )

{

memmap_type = "Multiboot-e820";

while ( (bytes < mbi->mmap_length) && (e820_raw_nr < E820MAX) )

Re: [Xen-users] Xen EFI boot how to?