LTO (Link-Time Optimisation) is an very useful feature which can
significantly reduce the size of U-Boot binaries. So far it has been
made available for selected ARM boards and sandbox.
However, incremental builds are much slower when LTO is used. For example,
an incremental build of sandbox takes 2.1 seconds on my machine, but 6.7
seconds with LTO enabled.
Add a NO_LTO parameter to the build, similar to NO_SDL, so it can be
disabled during development if needed, for faster builds.
Add some documentation about LTO while we are here.
Signed-off-by: Simon Glass <sjg@chromium.org>
The following Python packages are used by U-Boot, too:
* python3-asteval
* python3-subunit
* python3-testtools
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
At present U-Boot always builds dtc if CONFIG_OF_CONTROL is defined, even
when DTC is provided. The built dtc is not actually used, so this is a
waste of time.
Update the Makefile logic to build dtc only if one is not provided to the
build with the DTC variable. Add documentation to explain this.
This saves about 3.5 seconds of elapsed time on a clean build of
sandbox_spl for me.
Signed-off-by: Simon Glass <sjg@chromium.org>
These are out of date. Update them and point to the existing build
instructions to avoid duplication. Add a few that are missing.
Signed-off-by: Simon Glass <sjg@chromium.org>
Integrate the Dockerfile from
https://source.denx.de/u-boot/gitlab-ci-runner.git as of
commit bc6130d572f1 ("Dockerfile: Remove high UID/GID") and introduce a
short rST on how to build the container.
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>
* Move README.clang to doc/build/clang.rst and reformat as
reStructeredText.
* Indicate that -ffixed-r9 and -ffixed-x18 are used to reserve registers
for gd.
* Minor editing.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This adds a reST document for how to build U-Boot host tools,
including information for both Linux and Windows.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
