Commit 33712d7a authored by Thomas Petazzoni's avatar Thomas Petazzoni
Browse files

docs/manual: add FAQ entry about speeding up the build process 



This is a very frequently asked question, so let's add a FAQ entry
about it, that we can progressively extend with more advices for our
users.

[Thomas: remove the part about your boss buying new hardware, as
suggested by reviewers.]

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: default avatar"Yann E. MORIN" <yann.morin.1998@free.fr>
parent 298cd8ea

docs/manual/faq-troubleshooting.txt

+34 −0
Original line number Diff line number Diff line
@@ -205,3 +205,37 @@ On this matter, the Buildroot developers make this position statement: 
   upgrades by upgrading the entire root filesystem image at once,

   the image deployed to the embedded system is guaranteed to really

   be the one that has been tested and validated.



[[faq-speeding-up-build]]

=== How to speed-up the build process?



Since Buildroot often involves doing full rebuilds of the entire

system that can be quite long, we provide below a number of tips to

help reduce the build time:



 * Use a pre-built external toolchain instead of the default Buildroot

   internal toolchain. By using a pre-built Linaro toolchain (on ARM)

   or a Sourcery CodeBench toolchain (for ARM, x86, x86-64, MIPS,

   etc.), you will save the build time of the toolchain at each

   complete rebuild, approximately 15 to 20 minutes. Note that

   temporarily using an external toolchain does not prevent you to

   switch back to an internal toolchain (that may provide a higher

   level of customization) once the rest of your system is working;



 * Use the +ccache+ compiler cache (see: xref:ccache[]);



 * Learn about rebuilding only the few packages you actually care

   about (see xref:rebuild-pkg[]), but beware that sometimes full

   rebuilds are anyway necessary (see xref:full-rebuild[]);



 * Make sure you are not using a virtual machine for the Linux system

   used to run Buildroot. Most of the virtual machine technologies are

   known to cause a significant performance impact on I/O, which is

   really important for building source code;



 * Make sure that you're using only local files: do not attempt to do

   a build over NFS, which significantly slows down the build. Having

   the Buildroot download folder available locally also helps a bit.



 * Buy new hardware. SSDs and lots of RAM are key to speeding up the

   builds.