xxv6
Reimplementation and extension of teaching operating system xv6.
Architectures (to be) included: ARM, MIPS64, i386 (the original xv6 implementation)
Our first goal is to port xv6 onto ARM and MIPS64 (Loongson 2H).
The guides for placing and organizing source codes are in FILES in each directory.
Remember to add license information on top of the source code :)
This repository supersedes xv6-Loongson3A, the code from which will be migrated there.
Please refer to the doc directory for documentations.
Toolchain
Ideally, the project should be compilable by the latest GCC (or cross-GCC if cross-compiling) toolchain available on either Linux distro.
If prebuilt packages are not available, it is always welcomed to use precompiled binaries and libraries provided by the manufacturers.
If you're a determined, patient geek, you can build your own cross-compiler from source.
Fedora
Fedora ships cross-compiler packages since release 18, and there's really no reason to keep using unsupported old versions.
To install MIPS toolchain, execute (replace dnf with yum if you're running
older release)
# dnf install gcc-mips64-linux-gnu
Installing ARM toolchain is similar:
# dnf install gcc-arm-linux-gnu
Debian (not tested)
Cross-compilers are provided in sid, or unstable branch in Debian.
Unfortunately, one should usually upgrade to unstable from testing, which, in turn, should be upgraded from stable.
If you don't want to risk your machine being "unstable" (though not unstable as it seems - Ubuntu is based on Debian unstable branch), or regard the whole process as troublesome, simply jump to the Third-party section.
Upgrading between branches is simply done by modifying /etc/apt/sources.list
and changing sources from testing to unstable.
After upgrading, the toolchains could be installed by
$ sudo apt-get install gcc-4.9-arm-linux-gnueabi
if you're playing with ARM board, or
$ sudo apt-get install gcc-4.9-mipsel-linux-gnu
if you're hacking a Loongson box.
Replace 4.9 with 5 if you want to try GCC 5.
Ubuntu (not tested)
Awkwardly, Ubuntu ships gcc-4.9-arm-linux-gnueabi, but does not ship the
MIPS equivalent.
For ARM developers, running
$ sudo apt-get install gcc-4.9-arm-linux-gnueabi
would do everything.
Obtaining MIPS toolchain is even more complicated. First, you need to install
gdebi:
$ sudo apt-get install gdebi
Download and install by gdebi the following .deb packages from Debian sid
repository, in the order given:
binutils-mipsel-linux-gnu
cpp-4.9-mipsel-linux-gnu
gcc-4.9-mipsel-linux-gnu
Third-party
Loongson provided the compiler suite for building kernel here However, Loongson only supports GCC 4.4.0, which is quite obsolete compared to the now-popular version 4.9.x or 5.x.x.
Another good choice is Sourcery Codebench from Mentor Graphics. The MIPS toolchain archive could be downloaded here.
$PATH (and $LD_LIBRARY_PATH for Loongson's compiler) should be modified
accordingly to contain the binaries and libraries provided.
Read /etc/profile and put the paths into appropriate files and/or locations.
(TODO: add third-party ARM cross-compiler providers)
Build from source
(TODO: write source build instructions for ARM/IA32/MIPS)