[docs] Some typographical fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190324 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Sean Silva 2013-09-09 19:05:03 +00:00
parent c573305bce
commit 7f2576ddb0

View File

@ -22,15 +22,15 @@ nowadays) to a hard-float ARM target (most ARM targets nowadays).
The packages you'll need are:
* cmake
* ninja-build (from backports in Ubuntu)
* gcc-4.7-arm-linux-gnueabihf
* gcc-4.7-multilib-arm-linux-gnueabihf
* binutils-arm-linux-gnueabihf
* libgcc1-armhf-cross
* libsfgcc1-armhf-cross
* libstdc++6-armhf-cross
* libstdc++6-4.7-dev-armhf-cross
* ``cmake``
* ``ninja-build`` (from backports in Ubuntu)
* ``gcc-4.7-arm-linux-gnueabihf``
* ``gcc-4.7-multilib-arm-linux-gnueabihf``
* ``binutils-arm-linux-gnueabihf``
* ``libgcc1-armhf-cross``
* ``libsfgcc1-armhf-cross``
* ``libstdc++6-armhf-cross``
* ``libstdc++6-4.7-dev-armhf-cross``
Configuring CMake
-----------------
@ -39,32 +39,29 @@ For more information on how to configure CMake for LLVM/Clang,
see :doc:`CMake`.
The CMake options you need to add are:
* -DCMAKE_CROSSCOMPILING=True
* -DCMAKE_INSTALL_PREFIX=<install-dir>
* -DLLVM_TABLEGEN=<path-to-host-bin>/llvm-tblgen
* -DCLANG_TABLEGEN=<path-to-host-bin>/clang-tblgen
* -DLLVM_DEFAULT_TARGET_TRIPLE=arm-linux-gnueabihf
* -DLLVM_TARGET_ARCH=ARM
* -DLLVM_TARGETS_TO_BUILD=ARM
* -DCMAKE_CXX_FLAGS='-target armv7a-linux-gnueabihf -mcpu=cortex-a9
-I/usr/arm-linux-gnueabihf/include/c++/4.7.2/arm-linux-gnueabihf/
-I/usr/arm-linux-gnueabihf/include/ -mfloat-abi=hard
-ccc-gcc-name arm-linux-gnueabihf-gcc'
* ``-DCMAKE_CROSSCOMPILING=True``
* ``-DCMAKE_INSTALL_PREFIX=<install-dir>``
* ``-DLLVM_TABLEGEN=<path-to-host-bin>/llvm-tblgen``
* ``-DCLANG_TABLEGEN=<path-to-host-bin>/clang-tblgen``
* ``-DLLVM_DEFAULT_TARGET_TRIPLE=arm-linux-gnueabihf``
* ``-DLLVM_TARGET_ARCH=ARM``
* ``-DLLVM_TARGETS_TO_BUILD=ARM``
* ``-DCMAKE_CXX_FLAGS='-target armv7a-linux-gnueabihf -mcpu=cortex-a9 -I/usr/arm-linux-gnueabihf/include/c++/4.7.2/arm-linux-gnueabihf/ -I/usr/arm-linux-gnueabihf/include/ -mfloat-abi=hard -ccc-gcc-name arm-linux-gnueabihf-gcc'``
The TableGen options are required to compile it with the host compiler,
so you'll need to compile LLVM (or at least `llvm-tblgen`) to your host
so you'll need to compile LLVM (or at least ``llvm-tblgen``) to your host
platform before you start. The CXX flags define the target, cpu (which
defaults to fpu=VFP3 with NEON), and forcing the hard-float ABI. If you're
defaults to ``fpu=VFP3`` with NEON), and forcing the hard-float ABI. If you're
using Clang as a cross-compiler, you will *also* have to set ``-ccc-gcc-name``,
to make sure it picks the correct linker.
Most of the time, what you want is to have a native compiler to the
platform itself, but not others. It might not even be feasible to
produce x86 binaries from ARM targets, so there's no point in compiling
all back-ends. For that reason, you should also set the "TARGETS_TO_BUILD"
to only build the ARM back-end.
all back-ends. For that reason, you should also set the
``TARGETS_TO_BUILD`` to only build the ARM back-end.
You must set the CMAKE_INSTALL_PREFIX, otherwise a ``ninja install``
You must set the ``CMAKE_INSTALL_PREFIX``, otherwise a ``ninja install``
will copy ARM binaries to your root filesystem, which is not what you
want.
@ -76,7 +73,7 @@ running CMake:
#. If you're using Clang as the cross-compiler, there is a problem in
the LLVM ARM back-end that is producing absolute relocations on
position-independent code (R_ARM_THM_MOVW_ABS_NC), so for now, you
position-independent code (``R_ARM_THM_MOVW_ABS_NC``), so for now, you
should disable PIC:
.. code-block:: bash
@ -88,25 +85,25 @@ running CMake:
#. The ARM libraries won't be installed in your system, and possibly
not easily installable anyway, so you'll have to build/download
them separately. But the CMake prepare step, which check for
dependencies, will check the `host` libraries, not the `target`
them separately. But the CMake prepare step, which checks for
dependencies, will check the *host* libraries, not the *target*
ones.
A quick way of getting the libraries is to download them from
a distribution repository, like Debian (http://packages.debian.org/wheezy/),
and download the missing libraries. Note that the `libXXX`
will have the shared objects (.so) and the `libXXX-dev` will
give you the headers and the static (.a) library. Just in
and download the missing libraries. Note that the ``libXXX``
will have the shared objects (``.so``) and the ``libXXX-dev`` will
give you the headers and the static (``.a``) library. Just in
case, download both.
The ones you need for ARM are: ``libtinfo``, ``zlib1g``,
``libxml2`` and ``liblzma``. In the Debian repository you'll
find downloads for all architectures.
After you download and unpack all `.deb` packages, copy all
After you download and unpack all ``.deb`` packages, copy all
``.so`` and ``.a`` to a directory, make the appropriate
symbolic links (if necessary), and add the relevant ``-L``
and ``-I`` paths to -DCMAKE_CXX_FLAGS above.
and ``-I`` paths to ``-DCMAKE_CXX_FLAGS`` above.
Running CMake and Building
@ -124,9 +121,9 @@ If you're using Clang as the cross-compiler, run:
$ CC='clang' CXX='clang++' cmake -G Ninja <source-dir> <options above>
If you have clang/clang++ on the path, it should just work, and special
If you have ``clang``/``clang++`` on the path, it should just work, and special
Ninja files will be created in the build directory. I strongly suggest
you to run cmake on a separate build directory, *not* inside the
you to run ``cmake`` on a separate build directory, *not* inside the
source tree.
To build, simply type:
@ -151,7 +148,7 @@ via:
$ ninja install
which will create a sysroot on the install-dir. You can then TarGz
which will create a sysroot on the install-dir. You can then tar
that directory into a binary with the full triple name (for easy
identification), like:
@ -160,9 +157,9 @@ identification), like:
$ ln -sf <install-dir> arm-linux-gnueabihf-clang
$ tar zchf arm-linux-gnueabihf-clang.tar.gz arm-linux-gnueabihf-clang
If you copy that TarBall to your target board, you'll be able to use
If you copy that tarball to your target board, you'll be able to use
it for running the test-suite, for example. Follow the guidelines at
http://llvm.org/docs/lnt/quickstart.html, unpack the TarBall in the
http://llvm.org/docs/lnt/quickstart.html, unpack the tarball in the
test directory, and use options:
.. code-block:: bash