GSoC

Here is the latest from Xen UEFI land:

• We can boot to UEFI Shell, finally. The hurdles were -
• Different PCI I/O range compared to Qemu, this resulted in a domain crash when an emulated I/O device tried to register for already registered ports. Boo.
• ACPI timer block hardcoded by Xen at I/O 0xB000. Yes, modifying the "special BAR" has no effect, so UEFI TimerLib code needs to be careful in configuring the timer... if the PCI registers already look configured - use selected values. They are now set once in hvmloader.
• 8259 PIC ExtInt routing needed to be enabled in APIC inside hvmloader, because TianoCore has no APIC support.
• Started making OvmfPkg Xen aware. This was necessarily for at least registering the right I/O ranges. Now, the hypercall pages are populated and a GUIDed HOB containing Xen hypervisor info is published. This will be consumed by the hypervisor DXE.

I see the overall layering as being something like -

• Hypervisor driver - consumes HOB, publishes the EFI_XEN_HYPERCALL_PROTOCOL.
• XenTables driver - exposes Xen ACPI and SMBIOS tables, which were built into hvmloader.
• XenBus driver - consumes Hypervisor driver, creates child nodes for virtual I/O devices, publishes EFI_XEN_BUS_PROTOCOL.
• XenStore driver - exercises XenBus interface, allows SIMPLE_FILE_IO_PROTOCOL access to XenStore nodes.
• Blockfront, Netfront, Fbfront drivers for block, network and video, respectively.

Latest patches as usual at https://github.com/andreiw/andreiw-wip/tree/master/xen/ovmf-support.