I'm working on porting FreeGLUT for Android, and FreeGLUT is switching to CMake.
I'm more familiar with the GNU Autotools myself, and I'm used to cross-compile with a simple:
./configure --host=arm-linux-androideabi
Can we do that with CMake? Well, it's not well-documented, but yes :)
Let's see how to do that for Android (smartphones) and MinGW (.exe for windows).
The principle is:
- write a "toolchain" CMake script that defines the cross-compiler,
- mention you're using a "GNU" compiler (a.k.a. GCC) so CMake automatically looks for prefixed cross-compilers tools such as
arm-linux-androideabi-cpp or arm-linux-androideabi-ld.
- pass the toolchain script to CMake using the predefined
CMAKE_TOOLCHAIN_FILE variable.
- REMOVE all the CMake-generated files when you change anything, CMake does not rebuild its cache when the toolchain script or PATH is modified, this creates misleading errors. Hence, building in a subdirectory is crucial.
Here's a simple toolchain script:
SET(CMAKE_SYSTEM_NAME Linux) # Tell CMake we're cross-compiling
include(CMakeForceCompiler)
# Prefix detection only works with compiler id "GNU"
# CMake will look for prefixed g++, cpp, ld, etc. automatically
CMAKE_FORCE_C_COMPILER(arm-linux-androideabi-gcc GNU)
SET(ANDROID TRUE)
Note:
SET(ANDROID TRUE) is not mandatory for CMake, it's just used to detect an Android build in the particular case of FreeGLUT development.
Here's how to invoke it:
PATH=/usr/src/ndk-standalone-9/bin:$PATH
cd /usr/src/freeglut-3.0.0/
mkdir cross-android/ && cd cross-android/
cmake \
-D CMAKE_TOOLCHAIN_FILE=../android_toolchain.cmake \
-D CMAKE_INSTALL_PREFIX=/freeglut \
..
make -j4
make install DESTDIR=$(pwd)
Now here's a slightly more complex toolchain for MinGW.
The main issue with MinGW is that there are at least 4 possible prefixes depending on which version and which distro you're using. So I ask the user to specify it with
GNU_HOST:
SET(CMAKE_SYSTEM_NAME Windows)
include(CMakeForceCompiler)
IF("$ GNU_HOST " STREQUAL "")
SET(GNU_HOST i586-mingw32msvc)
ENDIF()
# Prefix detection only works with compiler id "GNU"
CMAKE_FORCE_C_COMPILER($ GNU_HOST -gcc GNU)
# CMake doesn't automatically look for prefixed 'windres', do it manually:
SET(CMAKE_RC_COMPILER $ GNU_HOST -windres)
I wanted to print an error when
GNU_HOST is not specified, but the toolchain script is loaded multiple times, and the command-line variables are not always set (CMake is not super-clean in that regard). So I defined a default, that works.
Sample invocation:
apt-get install mingw-w64
mkdir cross-woe/ && cd cross-woe/
cmake \
-D GNU_HOST=x86_64-w64-mingw32 \
-D CMAKE_TOOLCHAIN_FILE=../mingw_cross_toolchain.cmake \
-D CMAKE_INSTALL_PREFIX=/freeglut \
..
make -j4
make install DESTDIR=$(pwd)
I used this technique to cross-compile my projects, or other projects that use CMake.
mingw-cross-env uses this technique (abeilt with explicit definition of all compiler tools) to provide pre-built windows libraries without altering the existing CMake scripts.
Do you people have tips or a better technique to cross-compile with CMake?
We're now 2.5 months in 2012 and I'm indeed getting closer of my first
big goal of the year : the 80km run of Paris Ecotrail.
The race takes place next Saturday, March 24th, with a start at 12:00
in the South-West of Paris area (close to our place). The race is
mostly a trail race in woods and forests in the neighbourhood of
Paris, going up and down in our small hills and valleys, passing along
pools and lakes and indeed showing the natural beauties we have less
than 20km away from center Paris.
The race ends at the Eiffel Tower. And they really mean it! The race
ends at Eiffel Tower's *first floor* after climbing the steps
there. Those of you who have been there can imagine the surprise of
tourists from all over the world when hundreds of "road warriors"
wearing water backpacks, head lamps and looking a bit tired come and
climb the Old Lady's stairs.
So, in case you happen to be touring in Paris on the week-end of March 24-25, just
pop up at Eiffel Tower around 10-11pm (yes, at night) and try to spot
a bubulle crawling up there to reach the finish line..:-)
To prepare this, I already ran 538km in 2012, mostly done either with
my daily commute runs...or with week-end long runs (up to 37km on
march 4th, and many others above 20km).
I ran two half-marathons as well: one in February, where I nearly
broke my record, finishing it in 1h37'45" even though this is a quite
though race with two hills. I was very in shape that day and was lucky
to run with a friend setting the pace for me, which helps a
lot. Another half-marathon last Sunday in Rambouillet was also a good
race, though I was secretly hoping to break my record there (the race
is flat, much more than the former one). I had however to slow down
from a 4'35"/km pace to 4'50"/km in order to preserve my
condition. And, finally, I completed the race in 1h39'53".
So, two half-marathons in less than 1h40 again. That sounds promising
for the Ecotrail (even if there nothing similar between a flat half-marathon
and a hilly ultra-trail) and also for the next marathon, in June.
I'll keep you posted about the Ecotrail race but I can announce in
advance that I'll be using the Runtastic app on my brand new Android
phone, and people will be able to follow my race live here. And
you'll even be able to cheer at /me..:-)
Next running update on Sunday 25th to give you the outcome....
Continuing at same pace (one release every two days), I can announce 
Some time ago I wrote about the 
I'm happy to announce that cluster-glue 1.0.9+hg2665-1~bpo60+1 is available in the backports repository for Debian GNU/Linux 6.0 ("Squeeze"). I uploaded the backport-version right after the package got migrated from unstable to testing last night.
This version of cluster-glue fixes a nasty bug in the IPMI STONITH resource agent, so everybody is highly advised to update to this version to make sure that STONITH via IPMI works as expected.
