Store and restore the frame around exceptions
Reduce the noise in pmap to regular levels
Remove unneeded bits of machine/bus.h on arm64
Add the start of the bus_space handling code
Add do_el1h_sync. For now it prints the exception details.
Add a comment for tha mair attributes
Fix the location of the attribute index field in the lower attributes.
Fix the attribute, we should now be using normal memory in pmap when backed
by physical memory. While here add pmap_kenter_device to insert a page of
device memory.
Use arm/arm/devmap.c to get pmap_{un,}mapdev. As we don't yet need the
rest of the code, for now, comment it out.
Implement the map and unmap functions.
Add pmap_{un,}mapdev to the required header.
Add the start of support for FDT as it is likely it will be used for
device enumeration on some SoCs.
Work around a bug with the Semihosting FS driver where it returns
EFI_ABORTED there is no data to read.
Nexus doesn't need machine/fdt.h remove the include and file.
Pass the dtb from loader to the kernel. For now loader tries to load
foundation.dtb from the disk and pass this to the kernel.

The dtb is expected to be after the kernel and the data passed in is its
offset from the start of the kernel.
Allow us to set verbose boot, along with the other flags loaders boot
command takes.
Adjust a comment to put the words in the correct order
Add entries for all bus_space functions, most are still NULL.
Use the memmap_bus tag in nexus
Add FDT to the kernel now it's supported.