- ./configure --build=armv7l-unknown-linux-gnueabihf
- --host=armv7l-unknown-linux-gnueabihf
- --target=armv7l-unknown-linux-gnueabihf --with-cpu=cortex-a9
- --with-float=hard --with-abi=aapcs-vfp --with-fpu=neon
- --enable-targets=arm --disable-optimized --enable-assertions
+ ../$LLVM_SRC_DIR/configure --build=armv7l-unknown-linux-gnueabihf \
+ --host=armv7l-unknown-linux-gnueabihf \
+ --target=armv7l-unknown-linux-gnueabihf --with-cpu=cortex-a9 \
+ --with-float=hard --with-abi=aapcs-vfp --with-fpu=neon \
+ --enable-targets=arm --enable-optimized --enable-assertions
+
+#. ARM development boards can be unstable and you may experience that cores
+ are disappearing, caches being flushed on every big.LITTLE switch, and
+ other similar issues. To help ease the effect of this, set the Linux
+ scheduler to "performance" on **all** cores using this little script:
+
+ .. code-block:: bash
+
+ # The code below requires the package 'cpufrequtils' to be installed.
+ for ((cpu=0; cpu<`grep -c proc /proc/cpuinfo`; cpu++)); do
+ sudo cpufreq-set -c $cpu -g performance
+ done
+
+#. Running the build on SD cards is ok, but they are more prone to failures
+ than good quality USB sticks, and those are more prone to failures than
+ external hard-drives (those are also a lot faster). So, at least, you
+ should consider to buy a fast USB stick. On systems with a fast eMMC,
+ that's a good option too.
+
+#. Make sure you have a decent power supply (dozens of dollars worth) that can
+ provide *at least* 4 amperes, this is especially important if you use USB
+ devices with your board.