Difference between revisions of "Compiling M5"

Revision as of 23:56, 20 August 2006

M5 runs on Linux, Mac OS X, OpenBSD, and Microsoft Windows (under Cygwin), 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.

Required Software

To build M5, you will need the following software:

• g++ version 3.4 or newer. Once upon a time, M5 built with g++ 2.95, but it probably doesn't anymore; < 3.4 seems to have some issues with templates.
• 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 to download SCons. If you do not have administrator privileges on the machine you are trying to compile on, you can use the "scons-local" package to install scons in your m5 directory, or install SCons in your home directory using the '--prefix=' option.

There a few utility scripts written in Perl, but Perl is not necessary to build or run the simulator.

Possible Targets

M5 can build many binaries each for a different guest architecture, simulation mode, and use. The currently available architectures are ALPHA, SPARC, and MIPS.

Each of these can built in two simulation modes:

• FS - Full System mode. This mode simulates a complete system including a kernel, I/O devices, etc. This mode currently only works with the ALPHA architecture.
• SE - Syscall Emulation mode. This mode simulates statically compiled binaries by functionally emulating any syscall they make.

For each possible architecture and mode, several different executables can be built:

• m5.debug - A binary used for debugging without any optimizations. Since no optimizations are done this binary is compiled the fastest, however since no optimizations are done it executes very slowly. (-g3 -gdwarf-2 -O0).
• m5.opt - A binary with debugging and optimization. This binary executes much faster than the debug binary and still provides all the debugging facility of the debug version. However when debugging source code it can be more difficult to use that the debug target. (-g -O3)
• m5.prof - This binary is like the opt target, however it also includes profiling support suitable for use with gprof. (-O3 -g -pg).
• m5.fast - This binary is the fastest binary and all debugging support is removed from the binary (including trace support). (-O3 -DNDEBUG)

Compiling

Starting in the root of the source tree, you can build M5 using a command of the form:

% scons build/<arch>_<mode>/m5.<binary>

where the items between <> are the architectures, modes and binaries listed above. For example:

% cd m5
% scons build/ALPHA_FS/m5.debug

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 compiled 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_FS/m5.debug. You can build other binaries by specifying them on the scons command line. Multiple targets can be included on a single command line. As with make, the "-j" option can be used to enable parallel builds (useful on multiprocessor hosts). For example, the following command will build both the optimized Alpha syscall emulation and debug MIPS syscall emulation targets using up to 4 concurrent processes:

% scons -j 4 build/ALPHA_SE/m5.opt scons build/MIPS_SE/m5.debug

Testing your build

Once you've compiled M5, you can verify that the build worked by running regression tests. Regression tests are also run via scons. The command to run all tests for a particular is constructed as follows:

% scons build/<target>/tests/<binary>

For example, to run the regression tests on ALPHA_FS/m5.opt, type:

% scons build/ALPHA_FS/tests/opt

The regression framework is integrated into the scons build process, so the command above will (re)build ALPHA_FS/m5.opt if necessary before running the tests. Also thanks to scons's dependence tracking, tests will be re-run only if the binary has been rebuilt since the last time the test was run. If the previous test run is still valid (as far as scons can tell), only a brief pass/fail message will be printed out based on the result of that previous test, rather than the full output and statistics diff that is printed when the test is actually executed.

Regression tests are further subdivided into three categories ("quick", "medium", and "long") based on runtime. You can run only the tests in a particular category by adding that category name to the target path, e.g.:

% scons build/ALPHA_FS/tests/opt/quick

(Note that currently the "medium" and "long" categories are empty; all of the tests are "quick".)

Specific tests can be run by appending the test name:

% scons build/ALPHA_FS/tests/opt/quick/10.linux-boot

For more details, see Regression tests.