Am 15. Februar 2024 22:10:25 MEZ schrieb Tom Rini trini@konsulko.com:
The first big issue is that the "gcc" file talked a lot about the general build requirements as well, but was titled in a gcc-centric manner. Solve this by renaming the file to compile.rst and more fully reflecting that it is general build instructions. Next, add a section about the prebuilt toolchains that are recommended (as they are the ones we use in CI), and update a few places to reference these vendor-neutral tools.
Next, we can include the reproducible builds section directly in the compile instructions rather than as a small standalone file.
Finally, we update the sandbox document to reflect both the name change as well as what is specifically required to build sandbox.
Signed-off-by: Tom Rini trini@konsulko.com
Cc: Heinrich Schuchardt xypron.glpk@gmx.de
doc/arch/sandbox/sandbox.rst | 5 ++- doc/build/{gcc.rst => compile.rst} | 64 ++++++++++++++++++++++++++---- doc/build/index.rst | 3 +- doc/build/reproducible.rst | 27 ------------- 4 files changed, 61 insertions(+), 38 deletions(-) rename doc/build/{gcc.rst => compile.rst} (73%) delete mode 100644 doc/build/reproducible.rst
diff --git a/doc/arch/sandbox/sandbox.rst b/doc/arch/sandbox/sandbox.rst index 5f8db126657f..f2ed5a25c115 100644 --- a/doc/arch/sandbox/sandbox.rst +++ b/doc/arch/sandbox/sandbox.rst @@ -39,11 +39,12 @@ integers can only be built on 64-bit hosts.
Note that standalone/API support is not available at present.
Prerequisites
-Install the dependencies noted in :doc:`../../build/gcc`. +In addition to the normal dependencies shows in the :doc:`general build +instructions <../../build/compile>` to enable display support SDL2 libraries +need to be available.
Basic Operation diff --git a/doc/build/gcc.rst b/doc/build/compile.rst similarity index 73% rename from doc/build/gcc.rst rename to doc/build/compile.rst index 3c6465772729..ef9c8545835a 100644 --- a/doc/build/gcc.rst +++ b/doc/build/compile.rst @@ -1,11 +1,19 @@
-Building with GCC
+Building U-Boot +===============
Dependencies
-For building U-Boot you need a GCC compiler for your host platform. If you -are not building on the target platform you further need a GCC cross compiler. +For building U-Boot you need the general build tools such as `make` and a C +compiler for your host platform. Next, if you are not building on the same +architecture as the target platform you further need a C cross compiler. +Furthermore, some target platforms require additional host tools to be present +and their package names may vary slightly dependinng on the naming scheme used +by a particular host OS.
+In general, GCC should be used for both the host and target C compiler. Using +:doc:`clang <clang>` is supported but please see the documented issues for it as +well.
Debian based
@@ -69,6 +77,17 @@ Depending on the build target further packages may be needed: * riscv64 S-mode targets: opensbi * some arm64 targets: arm-trusted-firmware +Prebuilt +~~~~~~~~ + +Another option, which the project uses for CI for example, is to use a prebuilt +toolchain. For the most part, we use the latest `kernel.org`_ prebuit binaries, +but there are a few architectures that require their own specific toolchains +still. + +In general, examples found within the documentation here refer to the tools +found here and exceptions will be noted where relevant. + Prerequisites ------------- @@ -112,11 +131,11 @@ command line or export it beforehand. CROSS_COMPILE=<compiler-prefix> make -Assuming cross compiling on Debian for ARMv8 this would be +Assuming cross compiling for ARMv8 this would be .. code-block:: bash - CROSS_COMPILE=aarch64-linux-gnu- make + CROSS_COMPILE=aarch64-linux- make
GCC uses triples to specify the architecture. With the suggested change building will fail on many distros, e.g. in our CI image.
cf. https://gcc.gnu.org/install/specific.html#aarch64-x-x
Build parameters
@@ -131,13 +150,40 @@ You can speed up compilation by parallelization using the -j parameter, e.g. .. code-block:: bash - CROSS_COMPILE=aarch64-linux-gnu- make -j$(nproc) + CROSS_COMPILE=aarch64-linux- make -j$(nproc)
ditto
Best regards
Heinrich
Further important build parameters are
- O=<dir> - generate all output files in directory <dir>, including .config
- V=1 - verbose build
+Reproducible builds +~~~~~~~~~~~~~~~~~~~
+In order to achieve reproducible builds, timestamps used in the U-Boot build +process have to be set to a fixed value.
+This is done using the SOURCE_DATE_EPOCH environment variable which specifies +the number of seconds since 1970-01-01T00:00:00Z.
+To build the sandbox with 2023-01-01T00:00:00Z as timestamp we can use:
+.. code-block:: bash
- make sandbox_defconfig
- SOURCE_DATE_EPOCH=1672531200 make
+This date is shown when we launch U-Boot:
+.. code-block:: console
- ./u-boot -T
- U-Boot 2023.01 (Jan 01 2023 - 00:00:00 +0000)
+The same effect can be obtained with buildman using the `-r` flag.
Devicetree compiler
@@ -176,6 +222,8 @@ builds during development, you can disable it by setting `NO_LTO` to `1`. NO_LTO=1 make +Note that not all platforms which enable LTO support disabling it however. + Other build targets@@ -195,3 +243,5 @@ Installation
The process for installing U-Boot on the target device is device specific. Please, refer to the board specific documentation :doc:`../board/index`.
+.. _`kernel.org`: https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/ diff --git a/doc/build/index.rst b/doc/build/index.rst index 7a4507b57461..5262b4f3c1b9 100644 --- a/doc/build/index.rst +++ b/doc/build/index.rst @@ -7,9 +7,8 @@ Build U-Boot :maxdepth: 2
source
- gcc
- compile clang
- reproducible docker tools buildman
diff --git a/doc/build/reproducible.rst b/doc/build/reproducible.rst deleted file mode 100644 index 8b030f469d7c..000000000000 --- a/doc/build/reproducible.rst +++ /dev/null @@ -1,27 +0,0 @@
-Reproducible builds
-In order to achieve reproducible builds, timestamps used in the U-Boot build -process have to be set to a fixed value.
-This is done using the SOURCE_DATE_EPOCH environment variable which specifies -the number of seconds since 1970-01-01T00:00:00Z.
-Example
-To build the sandbox with 2023-01-01T00:00:00Z as timestamp we can use:
-.. code-block:: bash
- make sandbox_defconfig
- SOURCE_DATE_EPOCH=1672531200 make
-This date is shown when we launch U-Boot:
-.. code-block:: console
- ./u-boot -T
- U-Boot 2023.01 (Jan 01 2023 - 00:00:00 +0000)
-The same effect can be obtained with buildman using the `-r` flag.