tests: Update test scripts to work with Python 3

Change-Id: I71b1e595765fed9e9f234c9722c33ac5348d4f11
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/15999
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

config: Make configs/common a Python package

Continue along the same line as the recent patch that made the
Ruby-related config scripts Python packages and make also the
configs/common directory a package.

All affected config scripts are updated (hopefully).

Note that this change makes it apparent that the current organisation
and naming of the config directory and its subdirectories is rather
chaotic. We mix scripts that are directly invoked with scripts that
merely contain convenience functions. While it is not addressed in
this patch we should follow up with a re-organisation of the
config structure, and renaming of some of the packages.

tests: Skip SPARC tests if the required binaries are missing

The full-system SPARC tests depend on several binaries that aren't
generally available to the wider community. Flag the tests as skipped
instead of failed if these binaries can't be found.

mem: Change AbstractMemory defaults to match the common case

This patch changes the default parameter value of conf_table_reported
to match the common case. It also simplifies the regression and config
scripts to reflect this change.

power: Add voltage domains to the clock domains

This patch adds the notion of voltage domains, and groups clock
domains that operate under the same voltage (i.e. power supply) into
domains. Each clock domain is required to be associated with a voltage
domain, and the latter requires the voltage to be explicitly set.

A voltage domain is an independently controllable voltage supply being
provided to section of the design. Thus, if you wish to perform
dynamic voltage scaling on a CPU, its clock domain should be
associated with a separate voltage domain.

The current implementation of the voltage domain does not take into
consideration cases where there are derived voltage domains running at
ratio of native voltage domains, as with the case where there can be
on-chip buck/boost (charge pumps) voltage regulation logic.

The regression and configuration scripts are updated with a generic
voltage domain for the system, and one for the CPUs.

config: Move the memory instantiation outside FSConfig

This patch moves the instantiation of the memory controller outside
FSConfig and instead relies on the mem_ranges to pass the information
to the caller (e.g. fs.py or one of the regression scripts). The main
motivation for this change is to expose the structural composition of
the memory system and allow more tuning and configuration without
adding a large number of options to the makeSystem functions.

The patch updates the relevant example scripts to maintain the current
functionality. As the order that ports are connected to the memory bus
changes (in certain regresisons), some bus stats are shuffled
around. For example, what used to be layer 0 is now layer 1.

Going forward, options will be added to support the addition of
multi-channel memory controllers.

regressions: update a couple of configs
The configs for pc-simple-timing-ruby, t1000-simple-atomic had not been
updated correctly in the patch 6e6cefc1db1f.

mem: More descriptive DRAM config names

This patch changes the class names of the variuos DRAM configurations
to better reflect what memory they are based on. The speed and
interface width is now part of the name, and also the alias that is
used to select them on the command line.

Some minor changes are done to the actual parameters, to better
reflect the named configurations. As a result of these changes the
regressions change slightly and the stats will be bumped in a separate
patch.

config: Added memory type to t1000 regression

This patch adds the memory type parameter to the t1000 regression.

Fix the SPARC fs regression by adding a call to createInterruptController.

SE/FS: Make SE vs. FS mode a runtime parameter.

Config: Keep track of uncached and cached ports separately.

This makes sure that the address ranges requested for caches and uncached ports
don't conflict with each other, and that accesses which are always uncached
(message signaled interrupts for instance) don't waste time passing through
caches.

python: Move more code into m5.util allow SCons to use that code.
Get rid of misc.py and just stick misc things in __init__.py
Move utility functions out of SCons files and into m5.util
Move utility type stuff from m5/__init__.py to m5/util/__init__.py
Remove buildEnv from m5 and allow access only from m5.defines
Rename AddToPath to addToPath while we're moving it to m5.util
Rename read_command to readCommand while we're moving it
Rename compare_versions to compareVersions while we're moving it.

Move all of the parameters of the Root SimObject so they are
directly configured by python. Move stuff from root.(cc|hh) to
core.(cc|hh) since it really belogs there now.
In the process, simplify how ticks are used in the python code.

add a sparc fs regression

src/dev/sparc/iob.cc:
don't warn on cpu restart/idle/halt stuff
tests/SConscript:
add sparc target in test Sconscript
util/regress:
Add SPARC_FS target in regress