Add a CMake based build system

This commit adds an alternate build system using CMake that operates indepenently of
the existing Kconfig+Kbuild+make based build system

tools/internal.cmake

@@ -0,0 +1,99 @@
+#
+# Copyright 2017, Data61
+# Commonwealth Scientific and Industrial Research Organisation (CSIRO)
+# ABN 41 687 119 230.
+#
+# This software may be distributed and modified according to the terms of
+# the GNU General Public License version 2. Note that NO WARRANTY is provided.
+# See "LICENSE_GPLv2.txt" for details.
+#
+# @TAG(DATA61_GPL)
+#
+
+cmake_minimum_required(VERSION 3.7.2)
+
+# File for helpers that are very specific to the kernel
+
+function(gen_invocation_header)
+    cmake_parse_arguments(PARSE_ARGV 0 "GEN" "LIBSEL4;ARCH;SEL4ARCH" "OUTPUT;XML" "")
+    if (NOT "${GEN_UNPARSED_ARGUMENTS}" STREQUAL "")
+        message(FATAL_ERROR "Unknown arguments to gen_invocation_header: ${GEN_UNPARSED_ARGUMENTS}")
+    endif()
+    # Ensure only one of arch or sel4arch
+    if (GEN_ARCH AND GEN_SEL4ARCH)
+        message(FATAL_ERROR "Can only specify one of ARCH or SEL4ARCH")
+    endif()
+    # OUTPUT and XML are required
+    if (("${GEN_OUTPUT}" STREQUAL "") OR ("${GEN_XML}" STREQUAL ""))
+        message(FATAL_ERROR "OUTPUT and XML must both be specified")
+    endif()
+    set(arch_setting "")
+    if (GEN_ARCH)
+        set(arch_setting "--arch")
+    elseif (GEN_SEL4ARCH)
+        set(arch_setting "--sel4_arch")
+    endif()
+    set(libsel4_setting "")
+    if (GEN_LIBSEL4)
+        set(libsel4_setting "--libsel4")
+    endif()
+    # Turn the input xml into an absolute path as we build commands that may be
+    # be run with a working directory that is not the current source directory
+    get_absolute_source_or_binary(xml_absolute "${GEN_XML}")
+    add_custom_command(OUTPUT "${GEN_OUTPUT}"
+        COMMAND rm -f "${GEN_OUTPUT}"
+        COMMAND "${PYTHON}" "${INVOCATION_ID_GEN_PATH}" --xml "${xml_absolute}"
+            ${libsel4_setting} ${arch_setting} --dest "${GEN_OUTPUT}"
+        DEPENDS "${xml_absolute}" "${INVOCATION_ID_GEN_PATH}"
+        COMMENT "Generate invocation header ${GEN_OUTPUT}"
+    )
+endfunction(gen_invocation_header)
+
+# Adds files to the global sources list, but only if the supplied dependencies are met.
+# A dependency lists can be specified with DEP and CFILES are added to c_sources whilst
+# ASMFILES are added to asm_sources. An PREFIX can be given as path to prefix to each
+# C and ASM file given
+function(add_sources)
+    cmake_parse_arguments(PARSE_ARGV 0 "ADD" "" "DEP;PREFIX" "CFILES;ASMFILES")
+    if(NOT "${ADD_UNPARSED_ARGUMENTS}" STREQUAL "")
+        message(FATAL_ERROR "Unknown arguments to add_c_sources: ${ADD_UNPARSED_ARGUMENTS}")
+    endif()
+    # Need to prefix files with the CMAKE_CURRENT_SOURCE_DIR as we use these
+    # in custom commands whose working directory is not the source directory
+    # Also need to ensure that if an additional prefix wasn't specified by the
+    # caller, that we don't add an additional /, as this will screw up file sorting
+    if(NOT "${ADD_PREFIX}" STREQUAL "")
+        set(ADD_PREFIX "${ADD_PREFIX}/")
+    endif()
+    set(ADD_PREFIX "${CMAKE_CURRENT_SOURCE_DIR}/${ADD_PREFIX}")
+    foreach(file IN LISTS ADD_CFILES)
+        list(APPEND new_c_sources "${ADD_PREFIX}${file}")
+    endforeach()
+    foreach(file IN LISTS ADD_ASMFILES)
+        list(APPEND new_asm_sources "${ADD_PREFIX}${file}")
+    endforeach()
+    list_append_if(c_sources "${ADD_DEP}" ${new_c_sources})
+    list_append_if(asm_sources "${ADD_DEP}" ${new_asm_sources})
+endfunction(add_sources)
+
+# If the dependencies list in the 'dep' argument is true then a bf file is added
+# to the bf_declarations list. The format of file+prefix+path is used in order to
+# separate where the bf file is located in the source, versus where it will get
+# generated.
+function(add_bf_source_old dep file prefix path)
+    list_append_if(bf_declarations "${dep}" "${CMAKE_CURRENT_SOURCE_DIR}/${prefix}/${path}/${file}:${path}")
+endfunction(add_bf_source_old)
+
+# Macro for allowing different archs etc to set the kernel type to 32-bit
+macro(set_kernel_32)
+    config_set(KernelWordSize WORD_SIZE 32)
+    set(Kernel64 OFF CACHE INTERNAL "")
+    set(Kernel32 ON CACHE INTERNAL "")
+endmacro(set_kernel_32)
+
+# Macro for allowing different archs etc to set the kernel type to 64-bit
+macro(set_kernel_64)
+    config_set(KernelWordSize WORD_SIZE 64)
+    set(Kernel64 ON CACHE INTERNAL "")
+    set(Kernel32 OFF CACHE INTERNAL "")
+endmacro(set_kernel_64)