1===================================================================
2How To Build On ARM
3===================================================================
4
5Introduction
6============
7
8This document contains information about building/testing LLVM and
9Clang on ARM.
10
11Notes On Building LLVM/Clang on ARM
12=====================================
13Here are some notes on building/testing LLVM/Clang on ARM. Note that
14ARM encompasses a wide variety of CPUs; this advice is primarily based
15on the ARMv6 and ARMv7 architectures and may be inapplicable to older chips.
16
17#. If you are building LLVM/Clang on an ARM board with 1G of memory or less,
18   please use ``gold`` rather then GNU ``ld``.
19   Building LLVM/Clang with ``--enable-optimized``
20   is prefered since it consumes less memory. Otherwise, the building
21   process will very likely fail due to insufficient memory. In any
22   case it is probably a good idea to set up a swap partition.
23
24#. If you want to run ``make
25   check-all`` after building LLVM/Clang, to avoid false alarms (eg, ARCMT
26   failure) please use at least the following configuration:
27
28   .. code-block:: bash
29
30     $ ../$LLVM_SRC_DIR/configure --with-abi=aapcs-vfp
31
32#. The most popular linaro/ubuntu OS's for ARM boards, eg, the
33   Pandaboard, have become hard-float platforms. The following set
34   of configuration options appears to be a good choice for this
35   platform:
36
37   .. code-block:: bash
38
39     ./configure --build=armv7l-unknown-linux-gnueabihf \
40     --host=armv7l-unknown-linux-gnueabihf \
41     --target=armv7l-unknown-linux-gnueabihf --with-cpu=cortex-a9 \
42     --with-float=hard --with-abi=aapcs-vfp --with-fpu=neon \
43     --enable-targets=arm --enable-optimized --enable-assertions
44