Tools Used in 6.828

If you use the MIT Athena machines that run Linux, then most of the software needed will be installed locally. All additional software is available in the exokernel locker: just type add exokernel to get access to them.

If you're using a personal machine running Debathena, you can install the necessary tools by running:

sudo apt-get install -y build-essential gcc-multilib gdb

We highly recommend using a Debathena machine, such as athena.dialup.mit.edu, to work on the labs. However, if you do not have a Debathena machine, you can compile the toolchain, which should allow you to do the labs on OS X. Do not attempt to work on the labs while using Windows.

For an overview of useful commands in the tools used in 6.828, see the lab tools guide.

Compiler Toolchain

Note: The course staff have not verified that these instructions still work. They are reproduced from the Fall 2012 offering.

Most modern Linuxes and BSDs have an ELF toolchain compatible with the 6.828 labs. That is, the system-standard gcc, as, ld and objdump should just work. The 6.828 lab makefile should automatically detect this. However, if your machine is in this camp and the makefile fails to detect this, you can override it by adding the following line to conf/env.mk:

GCCPREFIX=

If you are using something other than standard x86 Linux or BSD, you will need the GNU C compiler toolchain, configured and built as a cross-compiler for the target i386-jos-elf, as well as the GNU debugger, configured for the i386-jos-elf toolchain. You can download the specific versions we used via these links, although any recent versions of gcc, binutils, and GDB should work:

• http://ftpmirror.gnu.org/binutils/binutils-2.21.1.tar.bz2
• http://ftpmirror.gnu.org/gcc/gcc-4.5.1/gcc-core-4.5.1.tar.bz2
• http://ftpmirror.gnu.org/gdb/gdb-6.8a.tar.gz

Once you've unpacked these archives, run the following commands as root:

$ cd binutils-2.21.1
$ ./configure --target=i386-jos-elf --disable-nls
$ make
$ make install
$ cd ../gcc-4.5.1
$ ./configure --target=i386-jos-elf --disable-nls --without-headers \
              --with-newlib --disable-threads --disable-shared \
              --disable-libmudflap --disable-libssp
$ make
$ make install
$ cd ../gdb-6.8
$ ./configure --target=i386-jos-elf --program-prefix=i386-jos-elf- \
              --disable-werror
$ make
$ make install

Then you'll have in /usr/local/bin a bunch of binaries with names like i386-jos-elf-gcc. The lab makefile should detect this toolchain and use it in preference to your machine's default toolchain. If this doesn't work, there are instructions on how to override the toolchain inside the GNUmakefile in the labs.

QEMU Emulator

QEMU is a modern and fast PC emulator. QEMU version 1.7.0 is set up on Athena for x86 machines in the exokernel locker.

Unfortunately, QEMU's debugging facilities, while powerful, are somewhat immature, so we highly recommend you use our patched version of QEMU instead of the stock version that may come with your distribution. The version installed on Athena is already patched. To build your own patched version of QEMU:

1. Clone the IAP 6.828 QEMU git repository git clone https://github.com/geofft/qemu.git -b 6.828-1.7.0
2. On Linux, you may need to install the SDL development libraries to get a graphical VGA window. On Debian/Ubuntu, this is the libsdl1.2-dev package.
3. Configure the source code
   1. Linux: ./configure --disable-kvm [--prefix=PFX] [--target-list="i386-softmmu x86_64-softmmu"]
   2. OS X: ./configure --disable-kvm --disable-sdl [--prefix=PFX] [--target-list="i386-softmmu x86_64-softmmu"] The prefix argument specifies where to install QEMU; without it QEMU will install to /usr/local by default. The target-list argument simply slims down the architectures QEMU will build support for.
4. Run make && make install