UEFI ExitBootServices

[manu%netbsd.org@localhost (Emmanuel Dreyfus)]

Hello

I am working on multiboot for EFI bootstrap, the target being to boot
xen.

This requires implementing the multiboot2 protocol [1]. I did most of
it, and it is able to boot Xen with legacy BIOS boostrap boot(8).
However, using EFI bootstrap bootx64.efi success is not there yet.

Adding debug messages in Xen, I know the hypervisor starts up, and I
have somes traces up to the UEFI ExitBootServices call. It fails:
Cannot exit boot services: ErrCode: 0x8000000000000002

Anyone has some hints about this? Why could this fail? A search on
internet suggests that ExitBootServices requires the memory map, and
that getting it modifies the memory map, hence it should be done twice,
but this is exactly what Xen does. ExitBootServices still fails on the
second call.

[1] https://www.gnu.org/software/grub/manual/multiboot2/multiboot.html

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu%netbsd.org@localhost