Compiling M5

M5 runs on Linux and OpenBSD, but should be easily portable to other Unix-like OSes. Cross-endian support has been mostly added, however this has not been extensively tested. All the syscall emulation (_SE) targets support running regardless of host/target endianess, however at present ALPHA_FS does not fully support big endian machines.

To build M5, you will need the following software:

• g++ version 3.0 or newer. Once upon a time, M5 built with g++ 2.95, but it probably doesn't anymore.
• Python, version 2.4 or newer.
• SCons, version 0.96.91 or newer.
• SWIG, version 1.3.28 or newer.

SCons is a powerful replacement for make. See here[1], to download SCons, and here for installation instructions. Note that you can install SCons in your home directory using the '--prefix=' option (see here for details) or use SCons Local if you do not have administrator privileges on the machine you are trying to compile on.

The regression tester and a few utility scripts are written in Perl, but Perl is not strictly necessary to build the simulator.

Once you have obtained and unpacked the M5 sources, the root of your of your M5 source tree should have three directories:

src 

This directory contains the sources for the simulator itself.

ext 

This directory contains external packages used by M5 that are not commonly installed on systems.

configs 

This directory contains sample script files that can be used to run M5 and as a starting place for your own configurations.

docs 

This directory has the doxygen output in it and any other interesting bits documentation we have

util 

This directory has random programs that are used in conjunction with M5 such as Python scripts to process data in an DB, submit jobs to a batch processing system, etc.

system 

This directory contains platform dependent code such as BIOS, hypervisor, that someone using M5 may want to modify.

There are multiple architectures, modes and binaries that M5 can build.

• Architectures

  ALPHA 

  Alpha ISA

  SPARC 

  SPARC ISA

  MIPS 

  MIPS ISA

• Types

  FS 

  A binary for full system simulation. This currently only works with the ALPHA target.

  SE 

  A binary for syscall emulation.

• Target

  debug 

  A binary with no optimization and all debugging features (g++ -ggdb -g3 -O0 -DDEBUG)

  opt 

  A binary with optimization and all debugging features (g++ -ggdb -g3 -O5 -DDEBUG)

  fast 

  A binary with optimization and no debugging features (g++ -ggdb -g3 -O5 -DNO_DEBUG)

  prof 

  A binary with optimization that generates profile output suitable to use with gprof

Starting in the root of this tree, you can build M5 and test your build using the following commands.

% cd m5
% scons build/<arch>_<type>/m5.<target>

scons: Reading SConscript files ...
Checking for C header file fenv.h... yes
Building in /tmp/newmem/build/ALPHA_FS
Options file /tmp/newmem/build/options/ALPHA_FS not found,
  using defaults in build_opts/ALPHA_FS
Compiling in ALPHA_FS with MySQL support.
scons: done reading SConscript files.
scons: Building targets ...
g++ -o build/ALPHA_FS/base/circlebuf.do -c -pipe -fno-strict-aliasing
    -Wall -Wno-sign-compare -Werror -Wundef -g3 -gdwarf-2 -O0
    -DTHE_ISA=ALPHA_ISA -DDEBUG -Iext/dnet -I/usr/include/python2.4
    -Ibuild/libelf/include -I/usr/include/mysql -Ibuild/ALPHA_FS
    build/ALPHA_FS/base/circlebuf.cc
...

If your output looked like the above, then congratulations, you've complied M5!

Each configuration is built in a separate subdirectory of m5/build. For each configuration, the various flavors of binaries are built in the same directory. The default binary that you built above is ALPHA_SE/m5.debug. You can build other binaries by specifying them on the scons command line, e.g. 'scons ALPHA_SE/m5.opt' or 'scons ALPHA_FS/m5.debug'.