fix(build): use DWARF 4 when building debug

GCC 11 and Clang 14 now use the DWARF 5 standard by default however
Arm-DS currently only supports up to version 4. Therefore, for debug
builds, ensure the DWARF 4 standard is used.
Also update references for Arm DS-5 to it's successor Arm-DS (Arm
Development Studio).

Change-Id: Ica59588de3d121c1b795b3699f42c31f032cee49
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>

Makefile

@@ -307,13 +307,8 @@ endif
 $(eval $(call add_define,DEBUG))
 ifneq (${DEBUG}, 0)
         BUILD_TYPE	:=	debug
-        TF_CFLAGS	+= 	-g
-
-        ifneq ($(findstring clang,$(notdir $(CC))),)
-             ASFLAGS		+= 	-g
-        else
-             ASFLAGS		+= 	-g -Wa,--gdwarf-2
-        endif
+        TF_CFLAGS	+=	-g -gdwarf-4
+        ASFLAGS		+=	-g -Wa,-gdwarf-4
 
         # Use LOG_LEVEL_INFO by default for debug builds
         LOG_LEVEL	:=	40

docs/getting_started/build-options.rst

@@ -1051,11 +1051,11 @@ To compile a debug version and make the build more verbose use
 
     make PLAT=<platform> DEBUG=1 V=1 all
 
-AArch64 GCC uses DWARF version 4 debugging symbols by default. Some tools (for
-example DS-5) might not support this and may need an older version of DWARF
-symbols to be emitted by GCC. This can be achieved by using the
-``-gdwarf-<version>`` flag, with the version being set to 2 or 3. Setting the
-version to 2 is recommended for DS-5 versions older than 5.16.
+AArch64 GCC 11 uses DWARF version 5 debugging symbols by default. Some tools
+(for example Arm-DS) might not support this and may need an older version of
+DWARF symbols to be emitted by GCC. This can be achieved by using the
+``-gdwarf-<version>`` flag, with the version being set to 2, 3, 4 or 5. Setting
+the version to 4 is recommended for Arm-DS.
 
 When debugging logic problems it might also be useful to disable all compiler
 optimizations by using ``-O0``.
@@ -1080,7 +1080,7 @@ It is also possible to introduce an infinite loop to help in debugging the
 post-BL2 phase of TF-A. This can be done by rebuilding BL1 with the
 ``SPIN_ON_BL1_EXIT=1`` build flag. Refer to the :ref:`build_options_common`
 section. In this case, the developer may take control of the target using a
-debugger when indicated by the console output. When using DS-5, the following
+debugger when indicated by the console output. When using Arm-DS, the following
 commands can be used:
 
 ::

docs/getting_started/prerequisites.rst

@@ -7,7 +7,6 @@ AArch32 and AArch64 target platforms.
 It may possible to build |TF-A| with combinations of software packages that are
 different from those listed below, however only the software described in this
 document can be officially supported.
-
 Build Host
 ----------
 
@@ -71,7 +70,7 @@ These tools are optional:
    source files (``.dts`` files). DTC is available for Linux through the package
    repositories of most distributions.
 
-- Arm `Development Studio 5 (DS-5)`_
+- Arm `Development Studio (Arm-DS)`_
 
    The standard software package used for debugging software on Arm development
    platforms and |FVP| models.
@@ -166,5 +165,5 @@ documentation, available `here <https://git-scm.com/docs/githooks>`_.
 .. _Gerrit Code Review: https://www.gerritcodereview.com/
 .. _Linaro Release Notes: https://community.arm.com/dev-platforms/w/docs/226/old-release-notes
 .. _Linaro instructions: https://community.arm.com/dev-platforms/w/docs/304/arm-reference-platforms-deliverables
-.. _Development Studio 5 (DS-5): https://developer.arm.com/products/software-development-tools/ds-5-development-studio
+.. _Development Studio (Arm-DS): https://developer.arm.com/Tools%20and%20Software/Arm%20Development%20Studio
 .. _Linaro Release 20.01: http://releases.linaro.org/members/arm/platforms/20.01