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Diffstat (limited to 'docs/configure.txt')
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diff --git a/docs/configure.txt b/docs/configure.txt new file mode 100644 index 000000000..3fadc1f48 --- /dev/null +++ b/docs/configure.txt @@ -0,0 +1,68 @@ +// -*- mode:doc; -*- +// vim: set syntax=asciidoc: + +[[toolchain]] + +Cross-compilation toolchain +--------------------------- + +A compilation toolchain is the set of tools that allows you to compile +code for your system. It consists of a compiler (in our case, +gcc+), +binary utils like assembler and linker (in our case, +binutils+) and a +C standard library (either +http://www.gnu.org/software/libc/libc.html[GNU Libc], +http://www.uclibc.org/[uClibc] or +http://www.musl-libc.org/[musl]). + +The system installed on your development station certainly already has +a compilation toolchain that you can use to compile an application +that runs on your system. If you're using a PC, your compilation +toolchain runs on an x86 processor and generates code for an x86 +processor. Under most Linux systems, the compilation toolchain uses +the GNU libc (glibc) as the C standard library. This compilation +toolchain is called the "host compilation toolchain". The machine on +which it is running, and on which you're working, is called the "host +system" footnote:[This terminology differs from what is used by GNU +configure, where the host is the machine on which the application will +run (which is usually the same as target)]. + +The compilation toolchain is provided by your distribution, and +OpenADK has nothing to do with it (other than using it to build a +cross-compilation toolchain and other tools that are run on the +development host). + +As said above, the compilation toolchain that comes with your system +runs on and generates code for the processor in your host system. As +your embedded system has a different processor, you need a +cross-compilation toolchain - a compilation toolchain that runs on +your _host system_ but generates code for your _target system_ (and +target processor). For example, if your host system uses x86 and your +target system uses ARM, the regular compilation toolchain on your host +runs on x86 and generates code for x86, while the cross-compilation +toolchain runs on x86 and generates code for ARM. + +OpenADK provides only one solution for the cross-compilation toolchain. +The versions for binutils, gcc, gdb and libc are fixed. It is a combination +of mostly the latest versions, which are known to work in this combination +and are known to produce usable firmware images. You normally do not need to +know the deep details, it is part of OpenADK policy to keep this part +simple for the user. + +You can only choose between three C libraries: +http://www.uclibc.org[uClibc], the +http://www.gnu.org/software/libc/libc.html[glibc] and +http://www.musl-libc.org[musl]. + +There are some minimal configuration options provided in +Toolchain settings+. +You can enable or disable the building of following components and toolchain +options: + +* GDB (enabled by default) + +* GNU C++ compiler (enabled by default, when disabled + will prevent some packages to show up in the menu selection) + +* Stack Smashing Support (SSP) support for GNU C/C++ Compiler (experimental, some packages will fail to build) + +* Link Time Optimization (LTO) support for GNU C/C++ Compiler (experimental, some packages will fail to build) + |