perf docs: Document cross compilation

Records the commands for cross compilation with two methods.

The first method relies on Multiarch. The second approach is to explicitly
specify the PKG_CONFIG variables, which is widely used in build system
(like Buildroot, Yocto, etc).

Co-developed-by: James Clark <james.clark@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Tested-by: Ian Rogers <irogers@google.com>
Cc: amadio@gentoo.org
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20240717082211.524826-7-leo.yan@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
This commit is contained in:
Leo Yan 2024-07-17 09:22:11 +01:00 committed by Namhyung Kim
parent f42596c738
commit d27087c76e

View File

@ -71,3 +71,31 @@ supported by GCC. UBSan detects undefined behaviors of programs at runtime.
$ UBSAN_OPTIONS=print_stacktrace=1 ./perf record -a
If UBSan detects any problem at runtime, it outputs a “runtime error:” message.
4) Cross compilation
====================
As Multiarch is commonly supported in Linux distributions, we can install
libraries for multiple architectures on the same system and then cross-compile
Linux perf. For example, Aarch64 libraries and toolchains can be installed on
an x86_64 machine, allowing us to compile perf for an Aarch64 target.
Below is the command for building the perf with dynamic linking.
$ cd /path/to/Linux
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
For static linking, the option `LDFLAGS="-static"` is required.
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
LDFLAGS="-static" -C tools/perf
In the embedded system world, a use case is to explicitly specify the package
configuration paths for cross building:
$ PKG_CONFIG_SYSROOT_DIR="/path/to/cross/build/sysroot" \
PKG_CONFIG_LIBDIR="/usr/lib/:/usr/local/lib" \
make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/perf
In this case, the variable PKG_CONFIG_SYSROOT_DIR can be used alongside the
variable PKG_CONFIG_LIBDIR or PKG_CONFIG_PATH to prepend the sysroot path to
the library paths for cross compilation.