arch: arm64: Support aarch64-gcc compiler

To be able to successfully compile the kernel for the ARM64 architecture
we have to tweak the compiler-related files to be able to use the
AArch64 GCC compiler.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>

arch/arm/aarch32.cmake

@@ -23,4 +23,6 @@ zephyr_ld_options(
   ${ARCH_FLAG}
   )
 
+set_property(GLOBAL PROPERTY PROPERTY_OUTPUT_FORMAT elf32-little${ARCH}) # BFD format
+
 add_subdirectory(core/aarch32)

arch/arm/aarch64.cmake

@@ -1,3 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 
+set_property(GLOBAL PROPERTY PROPERTY_OUTPUT_FORMAT elf64-littleaarch64) # BFD format
+
 add_subdirectory(core/aarch64)

cmake/compiler/gcc/target_arm.cmake

@@ -1,33 +1,42 @@
 # SPDX-License-Identifier: Apache-2.0
-list(APPEND TOOLCHAIN_C_FLAGS
+if(CONFIG_ARM64)
-  -mthumb
+  list(APPEND TOOLCHAIN_C_FLAGS
-  -mcpu=${GCC_M_CPU}
+    -mcpu=${GCC_M_CPU}
-  )
+    )
-list(APPEND TOOLCHAIN_LD_FLAGS
+  list(APPEND TOOLCHAIN_LD_FLAGS
-  -mthumb
+    -mcpu=${GCC_M_CPU}
-  -mcpu=${GCC_M_CPU}
+    )
-  )
-
-# Defines a mapping from GCC_M_CPU to FPU
-
-if(CONFIG_CPU_HAS_FPU_DOUBLE_PRECISION)
-  set(PRECISION_TOKEN)
 else()
-  set(PRECISION_TOKEN sp-)
+  list(APPEND TOOLCHAIN_C_FLAGS
-endif()
+    -mthumb
+    -mcpu=${GCC_M_CPU}
+    )
+  list(APPEND TOOLCHAIN_LD_FLAGS
+    -mthumb
+    -mcpu=${GCC_M_CPU}
+    )
 
-set(FPU_FOR_cortex-m4      fpv4-${PRECISION_TOKEN}d16)
+  # Defines a mapping from GCC_M_CPU to FPU
-set(FPU_FOR_cortex-m7      fpv5-${PRECISION_TOKEN}d16)
-set(FPU_FOR_cortex-m33     fpv5-${PRECISION_TOKEN}d16)
 
-if(CONFIG_FLOAT)
+  if(CONFIG_CPU_HAS_FPU_DOUBLE_PRECISION)
-  list(APPEND TOOLCHAIN_C_FLAGS -mfpu=${FPU_FOR_${GCC_M_CPU}})
+    set(PRECISION_TOKEN)
-  list(APPEND TOOLCHAIN_LD_FLAGS -mfpu=${FPU_FOR_${GCC_M_CPU}})
+  else()
-  if    (CONFIG_FP_SOFTABI)
+    set(PRECISION_TOKEN sp-)
-    list(APPEND TOOLCHAIN_C_FLAGS -mfloat-abi=softfp)
+  endif()
-    list(APPEND TOOLCHAIN_LD_FLAGS -mfloat-abi=softfp)
+
-  elseif(CONFIG_FP_HARDABI)
+  set(FPU_FOR_cortex-m4      fpv4-${PRECISION_TOKEN}d16)
-    list(APPEND TOOLCHAIN_C_FLAGS -mfloat-abi=hard)
+  set(FPU_FOR_cortex-m7      fpv5-${PRECISION_TOKEN}d16)
-    list(APPEND TOOLCHAIN_LD_FLAGS -mfloat-abi=hard)
+  set(FPU_FOR_cortex-m33     fpv5-${PRECISION_TOKEN}d16)
+
+  if(CONFIG_FLOAT)
+    list(APPEND TOOLCHAIN_C_FLAGS -mfpu=${FPU_FOR_${GCC_M_CPU}})
+    list(APPEND TOOLCHAIN_LD_FLAGS -mfpu=${FPU_FOR_${GCC_M_CPU}})
+    if    (CONFIG_FP_SOFTABI)
+      list(APPEND TOOLCHAIN_C_FLAGS -mfloat-abi=softfp)
+      list(APPEND TOOLCHAIN_LD_FLAGS -mfloat-abi=softfp)
+    elseif(CONFIG_FP_HARDABI)
+      list(APPEND TOOLCHAIN_C_FLAGS -mfloat-abi=hard)
+      list(APPEND TOOLCHAIN_LD_FLAGS -mfloat-abi=hard)
+    endif()
   endif()
 endif()

cmake/gcc-m-cpu.cmake

@@ -26,6 +26,8 @@ if("${ARCH}" STREQUAL "arm")
     set(GCC_M_CPU cortex-r4)
   elseif(CONFIG_CPU_CORTEX_R5)
     set(GCC_M_CPU cortex-r5)
+  elseif(CONFIG_CPU_CORTEX_A53)
+    set(GCC_M_CPU cortex-a53)
   else()
     message(FATAL_ERROR "Expected CONFIG_CPU_CORTEX_x to be defined")
   endif()

include/linker/linker-tool-gcc.h

@@ -16,11 +16,15 @@
 #define ZEPHYR_INCLUDE_LINKER_LINKER_TOOL_GCC_H_
 
 #if defined(CONFIG_ARM)
-#if defined(CONFIG_BIG_ENDIAN)
+	#if defined(CONFIG_ARM64)
-#define OUTPUT_FORMAT_ "elf32-bigarm"
+		#define OUTPUT_FORMAT_ "elf64-littleaarch64"
-#else
+	#else
-#define OUTPUT_FORMAT_ "elf32-littlearm"
+		#if defined(CONFIG_BIG_ENDIAN)
-#endif
+			#define OUTPUT_FORMAT_ "elf32-bigarm"
+		#else
+			#define OUTPUT_FORMAT_ "elf32-littlearm"
+		#endif
+	#endif
 	OUTPUT_FORMAT(OUTPUT_FORMAT_)
 #elif defined(CONFIG_ARC)
 	OUTPUT_FORMAT("elf32-littlearc", "elf32-bigarc", "elf32-littlearc")

include/toolchain/gcc.h

@@ -217,7 +217,7 @@ do {                                                                    \
 
 #if defined(_ASMLANGUAGE)
 
-#ifdef CONFIG_ARM
+#if defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
 
 #if defined(CONFIG_ISA_THUMB2)
 
@@ -370,7 +370,7 @@ do {                                                                    \
 
 #define GEN_ABS_SYM_END }
 
-#if defined(CONFIG_ARM)
+#if defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
 
 /*
  * GNU/ARM backend does not have a proper operand modifier which does not
@@ -385,7 +385,7 @@ do {                                                                    \
 		",%B0"                              \
 		"\n\t.type\t" #name ",%%object" :  : "n"(~(value)))
 
-#elif defined(CONFIG_X86) || defined(CONFIG_ARC)
+#elif defined(CONFIG_X86) || defined(CONFIG_ARC) || defined(CONFIG_ARM64)
 
 #define GEN_ABSOLUTE_SYM(name, value)               \
 	__asm__(".globl\t" #name "\n\t.equ\t" #name \