Fail with an error if the script returns an error. Additionally hook
stdio up to execute process to allow easier use of python debugging
tools if required.

This reduces chances of other parts of the script printing to stdout and
allows the compatibility strings file to be inspected or manually
changed for debugging purposes.

Updated YAML validation error message to use logging.warning,
forwarding the output to stderr. This would otherwise end up
in the CMake dts compatibility string.

This change moves all arm platform timers to drivers/timer
and renames them to the compatibility string specified in the dts.
Now the correct timer is included at build time based on the dts,
this follows the same pattern as the serial-refactor.
Have moved the arm generic_timer and priv_timer into the timer
folder and updated cmake configs appropriately.

Modify hardware_gen script to only include chosen
serial path. Added newlines to serial drivers to fix
concat issues when compiling. Move cmake macro RegisterDriver
 up a level to support timer refactor. Modify arm cmake to reflect
this.

This was causing errors with a reproducible build check in the binary
verification toolchains.

This is done because while GCC can infer the correct size of the operand
from the inline assembly, Clang cannot. Using the operand constraint by
providing "%w0" does not work with MRS and the simplest solution to use
word_t instead.

Moved imx6q-uart.c and imx31-uart.c -> imx.c and updated config.cmake
appropriately.

Added getDebugChar basic functionality for all platforms.

Updated config.cmake in drivers/serial to use the marco properly
and added license. Renamed all serial drivers to conform to style.
Moved include for configurations scripts below tools used by the kernel.

Have added a drivers/serial folder to kernel, where all serial drivers
will be kept. The point is to have the the dts parsed and generate cmake
to include the right uart.c file prefixed with the compatibility.
Have removed all io.c from plat and includes from plat/config.cmake and
updated CHANGES file.

Currently dts support is only for arm so makes
sense to move into arm config.cmake. Will eventually add RISC-V to
the dts list too.

Prio to this change the kernel would crash if a thread with no VCPU
attempted to seL4_VMEnter. As of this commit, an unknown syscall exception
will be raised and the kernel will not crash.

Rename plat_cleanInvalidateCache to plat_cleanInvalidateL2Cache to
indicate that it is a L2 cache maintenance operation only.

Parse the /reserved-memory node per the Linux spec[1].
Ignore regions marked as 'no-map', but keep other regions
as they should be OK to use as RAM.

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt?h=v5.0-rc6

These values are now autogenerated.

it's not guaranteed that node names will be globally unique,
so use the full path to the node instead.

this is needed for the BOOT_RODATA attribute

exynos5 platforms have to initialise custom hardware before initialising
the generic timer. This was forcing every other platform to call a
wrapper function. We instead define initTimer that exynos5 can override.

Previously seL4_PGDBits was calculated, which is inconstent with the rest
of the composite constants in libsel4, and makes size constants harder
to parse from the C.

This commit makes seL4_PGDBits consistant with other definitions, by making the definition an integer and checking it with a compile time assert.

This file is based on foundation-v8-gicv3.dts.

These have no effect when there aren't any definitions.

This allows for mapping of consecutive pages for a single device in the
kernel.

We currently only support Sv39 on RV64. Sv39 has a cannonical address
range of -2^38 and 2^38-1. This means that bits 63-39 must be equal to
bit 38, or that we sign extend from bit 39 to 63 based on the value of
bit 38. It also means that we only have 39 bits of addressable space,
which limits our max untype size.