Update to support EFI runtime outside the kernel virtual address space
by creating an EFI RT pmap that can be activated / deactivated when
required.

Adds support for EFI RT to ARM_MMU_EXTENDED (ASID) 32-bit Arm machines.

On Arm64 the usage of pmapboot_enter is reduced and the mappings are
created much later in the boot process -- now in cpu_startup_hook.
Backward compatiblity for KVA mapped RT from old bootaa64.efi is
maintained.

Adding support to other platforms should be easier as a result.

Fix bootarm build.

efiboot: Make FDT support optional on a per-arch basis.

Be explicit about building for little endian. This allows efiboot to be
built with the armv7be toolchain.

Add module support.

Clean up the banner so it fits in 80 columns and add some extra details
to the "version" command output.

branches: 1.3.2;
Add -mfloat-abi=soft so that gcc 8 doesn't emit FP instructions. This
fixes bootarm.efi compiled by gcc 8.

Consistently use ${RELEASEDIR}/${RELEASEMACHINE} instead of
${RELEASEDIR}/${MACHINE} (Paul Ripke)

branches: 1.1.4; 1.1.6;
Add efiboot support for 32-bit ARM targets.

Clean and invalidate the full data cache as the armv6_start.S code assumes
that the caches are disabled on entry which armv7_exec_kernel ensures.
When caches are disabled armv6_start.S will invalidate (not clean) the
cache and this can lose u-boot data for the u-boots that now don't
perform their own cache maintenance.

An example of such a u-boot is the banana pro that chuq@ has tried which
has

commit 8b5dea33584261cc5d600614970d1cbed6d99f91
Author: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Wed Mar 3 14:05:05 2021 +0100

efi_loader: disable GRUB_ARM32_WORKAROUND on ARCH_SUNXI

applied.

Improving things so that the architected caches could remain on would be
better, but that's a much bigger change / set of changes.

branches: 1.1.4; 1.1.38;
Add efiboot support for 32-bit ARM targets.

Clean and invalidate the full data cache as the armv6_start.S code assumes
that the caches are disabled on entry which armv7_exec_kernel ensures.
When caches are disabled armv6_start.S will invalidate (not clean) the
cache and this can lose u-boot data for the u-boots that now don't
perform their own cache maintenance.

An example of such a u-boot is the banana pro that chuq@ has tried which
has

commit 8b5dea33584261cc5d600614970d1cbed6d99f91
Author: Heinrich Schuchardt <xypron.glpk@gmx.de>
Date: Wed Mar 3 14:05:05 2021 +0100

efi_loader: disable GRUB_ARM32_WORKAROUND on ARCH_SUNXI

applied.

Improving things so that the architected caches could remain on would be
better, but that's a much bigger change / set of changes.

Allow an MD check in prepare_boot and use it on arm64 (aarch64) to check
that, if a big endian kernel is seen, the CPU is capable of supporting BE
data accesses at EL0 via ID_AA64MMFR0_EL1.BigEnd.

branches: 1.3.24;
Add a hook for MD specific info to print in the "ver" command. Use this
to print the value of the current execution level in bootaa64.

branches: 1.2.4; 1.2.14;
Jump to MARK_ENTRY instead of MARK_START

Add efiboot support for 32-bit ARM targets.