About Aboriginal Linux

# HG changeset patch # User Rob Landley # Date 1276729690 18000 # Node ID 34fb47276e30b9c50f70fb427282dd27737d36b2 # Parent 25b47a72fd70a6bf9894d77b0f9ccb13c8d0c289 Fluff up the "about" page a bit. diff -r 25b47a72fd70 -r 34fb47276e30 www/about.html --- a/www/about.html Wed Jun 16 18:07:54 2010 -0500 +++ b/www/about.html Wed Jun 16 18:08:10 2010 -0500 @@ -1,26 +1,80 @@ + +About Aboriginal Linux + -

Aboriginal Linux is a set of tools for building custom virtual -machines. It lets you boot virtual PowerPC, ARM, MIPS and other -exotic systems on your x86 laptop, and do development in them.

- -

Aboriginal Linux was written to serve the embedded community, but it -has other uses as well - portability auditing and cross-platform -regression testing, for starters.

- What is Aboriginal Linux?

-
Aboriginal Linux is a build system for creating bootable system -images to be run under virtualization, intended to reduce or even -eliminate the need for cross compiling.
+
+
Aboriginal Linux is a set of tools to build custom virtual machines. +It lets you boot virtual PowerPC, ARM, MIPS and +other exotic systems on +your x86 laptop (using an emulator such as QEMU). These virtual system +images provide a simple development environment within which you can compile +software and run the result.
+
+ +
Aboriginal Linux was written to serve the embedded community, but it +has other uses as well:
+ +
+
Allow package maintainers to reproduce and fix bugs on architecures +they don't have access to or experience with.
+ +
Bug reports can include a link to a prebuilt Aboriginal image and a +reproduction sequence (wget source, build, run this test). This provides +the maintainer both a way to demonstrate the issue, and a native +development environment in which to build and test their fix.
+ +
No special hardware is required for this, just an open source emulator +(generally QEMU) and a system image to run under it. Configure and make +your package as normal, using standard tool names (strip, ld, as, etc). +You can even build and test on a laptop in an airplane, without internet +access.
+
+ +
Build arbitrarily complex Linux distributions without messing with +cross compiling.
-
The build system is a series of bash scripts which create a small native -Linux development environment for each target, runnable on real hardware or -under emulators such as QEMU.
+
The point is to separate _what_ you build from _how_ you build. Build +systems have enough to do handling package dependencies and configuration +without entangling cross compiling into it. If one system builds the right +set of packages and another system works on the right type of hardware, life +is much easier if they can work together to produce a single result.
+ +
If you need to scale up development, Aboriginal Linux lets you throw +hardware at the scalability problem instead of engineering time, using distcc +acceleration and distributed package build clusters to compile entire +distribution repositories on racks of cheap x86 cloud servers.
+
+ +
Automated regression testing and portability auditing.
+ +
Aboriginal Linux lets you build the same package across multiple +architectures, and run the result immediately inside the emulator. You can +even set up a cron job to build and test regular repository snapshots of a +package's development version automatically.
-
For a list of currently supported targets, see the -screenshots page.
+
Stay up to date with current packages in unmodified "vanilla" form, +with easy upgrades and the ability to push your own changes +upstream.
+ +
Non-x86 targets often receive less testing than common desktop and server +hardware, so regressions accumulate. This can lead to a vicious cycle where +everybody sticks with private forks of old versions because making the new +ones work is too much trouble, and the new ones don't work because nobody's +testing and fixing them. The farther you fall behind, the harder it is to +catch up again, but only the most recent version accepts new patches, so +even the existing fixes don't go upstream.
+ +
Aboriginal Linux uses the same (current) package versions across all +architectures, in as similar a configuration as possible, and with as few +patches as we can get away with. We (intentionally) can't upgrade a package +for one target without upgrading it for all of them, so we can't put off +dealing with less-interesting targets.
+
+

For more information, see the documentation page.
@@ -29,22 +83,53 @@ Downloading Aboriginal Linux

-Source Code
-
The Aboriginal Linux source code is -a series of shell scripts which run to create the various binary -images. See the README for usage instructions, -and the release notes.
+
+
Prebuilt binary images are available +for each target, based on the current Aboriginal Linux release. This +includes cross compilers, native compilers, root filesystems suitable for +chroot, and system images for use with QEMU.
+
-
Several prebuilt binary images -are available, based on the current Aboriginal Linux release. The -README describes each tarball. The -release notes on the news page explain recent -changes.
+
The binary README describes each tarball. +The release notes explain recent changes.
+ +
Even if you plan to build your own images from source code, you should +probably start by familiarizing yourself with the (known working) binary +releases.

Development

+ +
+
To build a system image for a target, download the +Aboriginal Linux source code and run "./build.sh" +with the name of the target to build (or with no arguments to list available +targets). See the "config" file in the source for various environment +variables you can export to control the build. See the +source README for additional usage instructions, and the +release notes for recent changes.
+
+ +
Aboriginal Linux is a build system for creating bootable system images, +which can be configured to run either on real hardware or under emulators +(such as QEMU). It is intended to reduce or even +eliminate the need for further cross compiling, by doing all the cross +compiling necessary to bootstrap native development on a given target. +(That said, most of what the build does is create and use cross +compilers: we cross compile so you don't have to.)
+ +
The build system is implemented as a series of bash scripts which run to +create the various binary images. The "build.sh" script invokes the other +stages in the correct order, but the stages are designed to run individually. +(Nothing build.sh itself does is actually important.)
+ +
Aboriginal Linux is designed as a series of orthogonal layers (the stages +called by build.sh), to increase flexibility and minimize undocumented +dependencies. Each layer can be either omitted or replaced with something +else. The list of layers is in the source README.
+
The project maintains a development repository using the Mercurial source control system. This includes RSS feeds for each checkin