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diff --git a/docs/manual/embedded-basics.txt b/docs/manual/embedded-basics.txt deleted file mode 100644 index fdadf62fc..000000000 --- a/docs/manual/embedded-basics.txt +++ /dev/null @@ -1,112 +0,0 @@ -// -*- mode:doc; -*- - -Embedded system basics ----------------------- - -When developing an embedded system, there are a number of choices to -address: - -* the cross-toolchain: target architecture/C library/... -* the bootloader -* kernel options -* the device management -* the init system -* the package selection (busybox vs. "real" programs, ...) -* ... - -Some of these may be influenced by the target hardware. - -Some of the choices may also add some constraints when you develop the -final application for which your target is designed (e.g. some -functions may be provided by some C libraries and missing in some -others, ...). So, these choices should be carefully made. - -Buildroot allows you to set most of these options to fit your needs. - -Moreover, Buildroot provides an infrastructure for reproducing the -build process of your kernel, cross-toolchain, and embedded root -filesystem. Being able to reproduce the build process will be useful -when a component needs to be patched or updated or when another person -is supposed to take over the project. - -[[cross-compilation-and-cross-toolchain]] -Cross-compilation & cross-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 (for example -http://www.gnu.org/software/libc/libc.html[GNU Libc], -http://www.uclibc.org/[uClibc] or -http://www.fefe.de/dietlibc/[dietlibc]). - -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 -Buildroot 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. - -Even if your embedded system uses an x86 processor, you might be -interested in Buildroot for two reasons: - -* The compilation toolchain on your host certainly uses the GNU Libc - which is a complete but huge C standard library. Instead of using - GNU Libc on your target system, you can use uClibc which is a tiny C - standard library. If you want to use this C library, then you need a - compilation toolchain to generate binaries linked with it. Buildroot - can do that for you. - -* Buildroot automates the building of a root filesystem with all - needed tools like busybox. That makes it much easier than doing it - by hand. - -You might wonder why such a tool is needed when you can compile +gcc+, -+binutils+, +uClibc+ and all the other tools by hand. Of course doing -so is possible, but dealing with all of the configure options and -problems of every +gcc+ or +binutils+ version is very time-consuming -and uninteresting. Buildroot automates this process through the use -of Makefiles and has a collection of patches for each +gcc+ and -+binutils+ version to make them work on most architectures. - -Buildroot offers a number of options and settings that can be tuned -when defining the cross-toolchain (refer to xref:toolchain-custom[]). - -[[bootloader]] -Bootloader -~~~~~~~~~~ - -TODO - -[[device-management]] -Device management -~~~~~~~~~~~~~~~~~ - -TODO - -[[init-system]] -Init system -~~~~~~~~~~~ - -TODO |