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Andreas Hansson a6074016e2 Bridge: Remove NACKs in the bridge and unify with packet queue 
This patch removes the NACKing in the bridge, as the split
request/response busses now ensure that protocol deadlocks do not
occur, i.e. the message-dependency chain is broken by always allowing
responses to make progress without being stalled by requests. The
NACKs had limited support in the system with most components ignoring
their use (with a suitable call to panic), and as the NACKs are no
longer needed to avoid protocol deadlocks, the cleanest way is to
simply remove them.

The bridge is the starting point as this is the only place where the
NACKs are created. A follow-up patch will remove the code that deals
with NACKs in the endpoints, e.g. the X86 table walker and DMA
port. Ultimately the type of packet can be complete removed (until
someone sees a need for modelling more complex protocols, which can
now be done in parts of the system since the port and interface is
split).

As a consequence of the NACK removal, the bridge now has to send a
retry to a master if the request or response queue was full on the
first attempt. This change also makes the bridge ports very similar to
QueuedPorts, and a later patch will change the bridge to use these. A
first step in this direction is taken by aligning the name of the
member functions, as done by this patch.

A bit of tidying up has also been done as part of the simplifications.

Surprisingly, this patch has no impact on any of the
regressions. Hence, there was never any NACKs issued. In a follow-up
patch I would suggest changing the size of the bridge buffers set in
FSConfig.py to also test the situation where the bridge fills up.
2012-08-22 11:39:58 -04:00
build_opts Regression: Add a test for x86 timing full system ruby simulation 2012-04-25 22:43:36 -05:00
configs Bridge: Remove NACKs in the bridge and unify with packet queue 2012-08-22 11:39:58 -04:00
ext clang/gcc: Fix compilation issues with clang 3.0 and gcc 4.6 2012-04-14 05:43:31 -04:00
src Bridge: Remove NACKs in the bridge and unify with packet queue 2012-08-22 11:39:58 -04:00
system ARM: Add support for Versatile Express extended memory map 2012-03-01 17:26:31 -06:00
tests Bridge: Remove NACKs in the bridge and unify with packet queue 2012-08-22 11:39:58 -04:00
util util: Fix issues with style checker. 2012-07-27 16:08:05 -04:00
.hgignore .hgignore: added src/doxygen 2010-07-27 20:00:38 -07:00
.hgtags Added tag stable_2012_06_28 for changeset f75ee4849c40 2012-07-19 16:53:02 -07:00
COPYING copyright: Add code for finding all copyright blocks and create a COPYING file 2011-06-02 17:36:07 -07:00
LICENSE copyright: Add code for finding all copyright blocks and create a COPYING file 2011-06-02 17:36:07 -07:00
README Info: Clean up some info files. 2011-02-14 21:36:37 -08:00
SConstruct scons: Add LIBRARY_PATH from the user environment to Scons 2012-07-12 12:56:11 -04:00

README 

This is the M5 simulator.

For detailed information about building the simulator and getting
started please refer to http://www.m5sim.org.

Specific pages of interest are:
http://www.m5sim.org/wiki/index.php/Compiling_M5
http://www.m5sim.org/wiki/index.php/Running_M5

Short version:

1. If you don't have SCons version 0.98.1 or newer, get it from
http://wwww.scons.org.

2. If you don't have SWIG version 1.3.31 or newer, get it from
http://wwww.swig.org.

3. Make sure you also have gcc version 3.4.6 or newer, Python 2.4 or newer
(the dev version with header files), zlib, and the m4 preprocessor.

4. In this directory, type 'scons build/ALPHA_SE/tests/debug/quick'.  This
will build the debug version of the m5 binary (m5.debug) for the Alpha
syscall emulation target, and run the quick regression tests on it.

If you have questions, please send mail to m5-users@m5sim.org

WHAT'S INCLUDED (AND NOT)
-------------------------

The basic source release includes these subdirectories:
 - m5:
   - configs: simulation configuration scripts
   - ext: less-common external packages needed to build m5
   - src: source code of the m5 simulator
   - system: source for some optional system software for simulated systems
   - tests: regression tests
   - util: useful utility programs and files

To run full-system simulations, you will need compiled system firmware
(console and PALcode for Alpha), kernel binaries and one or more disk images. 
These files for Alpha are collected in a separate archive, m5_system.tar.bz2.
This file can he downloaded separately.

Depending on the ISA used, M5 may support Linux 2.4/2.6, FreeBSD, and the
proprietary Compaq/HP Tru64 version of Unix. We are able to distribute Linux
and FreeBSD bootdisks, but we are unable to distribute bootable disk images of
Tru64 Unix. If you have a Tru64 license and are interested in
obtaining disk images, contact us at m5-users@m5sim.org