1Performing an Initial Build
2===========================
3
4-  Before building TF-A, the environment variable ``CROSS_COMPILE`` must point
5   to your cross compiler.
6
7   For AArch64:
8
9   .. code:: shell
10
11       export CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf-
12
13   For AArch32:
14
15   .. code:: shell
16
17       export CROSS_COMPILE=<path-to-aarch32-gcc>/bin/arm-none-eabi-
18
19   It is possible to build TF-A using Clang or Arm Compiler 6. To do so
20   ``CC`` needs to point to the clang or armclang binary, which will
21   also select the clang or armclang assembler. Arm Compiler 6 will be selected
22   when the base name of the path assigned to ``CC`` matches the string
23   'armclang'. GNU binutils are required since the TF-A build system doesn't
24   currently support Arm Scatter files. Meaning the GNU linker is used by
25   default for Arm Compiler 6. Because of this dependency, ``CROSS_COMPILE``
26   should be set as described above.
27
28   For AArch64 using Arm Compiler 6:
29
30   .. code:: shell
31
32       export CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf-
33       make CC=<path-to-armclang>/bin/armclang PLAT=<platform> all
34
35   On the other hand, Clang uses LLVM linker (LLD) and other LLVM binutils by
36   default instead of GNU utilities (LLVM linker (LLD) 14.0.0 is known to
37   work with TF-A). ``CROSS_COMPILE`` need not be set for Clang. Please note,
38   that the default linker may be manually overridden using the ``LD`` variable.
39
40   Clang will be selected when the base name of the path assigned to ``CC``
41   contains the string 'clang'. This is to allow both clang and clang-X.Y
42   to work.
43
44   For AArch64 using clang:
45
46   .. code:: shell
47
48       make CC=<path-to-clang>/bin/clang PLAT=<platform> all
49
50-  Change to the root directory of the TF-A source tree and build.
51
52   For AArch64:
53
54   .. code:: shell
55
56       make PLAT=<platform> all
57
58   For AArch32:
59
60   .. code:: shell
61
62       make PLAT=<platform> ARCH=aarch32 AARCH32_SP=sp_min all
63
64   Notes:
65
66   -  If ``PLAT`` is not specified, ``fvp`` is assumed by default. See the
67      :ref:`Build Options` document for more information on available build
68      options.
69
70   -  (AArch32 only) Currently only ``PLAT=fvp`` is supported.
71
72   -  (AArch32 only) ``AARCH32_SP`` is the AArch32 EL3 Runtime Software and it
73      corresponds to the BL32 image. A minimal ``AARCH32_SP``, sp_min, is
74      provided by TF-A to demonstrate how PSCI Library can be integrated with
75      an AArch32 EL3 Runtime Software. Some AArch32 EL3 Runtime Software may
76      include other runtime services, for example Trusted OS services. A guide
77      to integrate PSCI library with AArch32 EL3 Runtime Software can be found
78      at :ref:`PSCI Library Integration guide for Armv8-A AArch32 systems`.
79
80   -  (AArch64 only) The TSP (Test Secure Payload), corresponding to the BL32
81      image, is not compiled in by default. Refer to the
82      :ref:`Test Secure Payload (TSP) and Dispatcher (TSPD)` document for
83      details on building the TSP.
84
85   -  By default this produces a release version of the build. To produce a
86      debug version instead, refer to the "Debugging options" section below.
87
88   -  The build process creates products in a ``build`` directory tree, building
89      the objects and binaries for each boot loader stage in separate
90      sub-directories. The following boot loader binary files are created
91      from the corresponding ELF files:
92
93      -  ``build/<platform>/<build-type>/bl1.bin``
94      -  ``build/<platform>/<build-type>/bl2.bin``
95      -  ``build/<platform>/<build-type>/bl31.bin`` (AArch64 only)
96      -  ``build/<platform>/<build-type>/bl32.bin`` (mandatory for AArch32)
97
98      where ``<platform>`` is the name of the chosen platform and ``<build-type>``
99      is either ``debug`` or ``release``. The actual number of images might differ
100      depending on the platform.
101
102-  Build products for a specific build variant can be removed using:
103
104   .. code:: shell
105
106       make DEBUG=<D> PLAT=<platform> clean
107
108   ... where ``<D>`` is ``0`` or ``1``, as specified when building.
109
110   The build tree can be removed completely using:
111
112   .. code:: shell
113
114       make realclean
115
116--------------
117
118*Copyright (c) 2020-2022, Arm Limited. All rights reserved.*
119