alpha: Stop using architecture specific register types.

Change-Id: I4052000014c9f6f9ecefd3f37e58595c61599484
Reviewed-on: https://gem5-review.googlesource.com/c/14461
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

arch,mem: Move page table construction into the arch classes.

This gets rid of an awkward NoArchPageTable class, and also gives the
arch a place to inject ISA specific parameters (specifically page size)
without having to have TheISA:: in the generic version of these types.

Change-Id: I1412f303460d5c43dafdb9b3cd07af81c908a441
Reviewed-on: https://gem5-review.googlesource.com/6981
Reviewed-by: Alexandru Duțu <alexandru.dutu@amd.com>
Maintainer: Gabe Black <gabeblack@google.com>

alpha: Move some initialization logic from loadState into unserialize.

The primary difference between loadState and unserialize, at least when
eventually using the default SimObject implementation of loadState, is that
unserialize is called only if there's a corresponding section in the
checkpoint being restored. In this particular case, the AlphaProcess class
calls the generic Process unserialize function, and that does other critical
initialization like set up the processes page table. If the unserialize
function isn't called, other serious problems would break the simulation
anyway.

This removes the final custom implementation of loadState.

Change-Id: If50062392196bd37efd5ba04fd7aee6907b00dc6
Reviewed-on: https://gem5-review.googlesource.com/4741
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

syscall_emul: [patch 5/22] remove LiveProcess class and use Process instead

The EIOProcess class was removed recently and it was the only other class
which derived from Process. Since every Process invocation is also a
LiveProcess invocation, it makes sense to simplify the organization by
combining the fields from LiveProcess into Process.

style: [patch 3/22] reduce include dependencies in some headers

Used cppclean to help identify useless includes and removed them. This
involved erroneously included headers, but also cases where forward
declarations could have been used rather than a full include.

syscall_emul: move mmapGrowsDown() to LiveProcess

The mmapGrowsDown() method was a static method on the OperatingSystem
class (and derived classes), which worked OK for the templated syscall
emulation methods, but made it hard to access elsewhere. This patch
moves the method to be a virtual function on the LiveProcess method,
where it can be overridden for specific platforms (for now, Alpha).

This patch also changes the value of mmapGrowsDown() from being false
by default and true only on X86Linux32 to being true by default and
false only on Alpha, which seems closer to reality (though in reality
most people use ASLR and this doesn't really matter anymore).

In the process, also got rid of the unused mmap_start field on
LiveProcess and OperatingSystem mmapGrowsUp variable.

misc: Add explicit overrides and fix other clang >= 3.5 issues

This patch adds explicit overrides as this is now required when using
"-Wall" with clang >= 3.5, the latter now part of the most recent
XCode. The patch consequently removes "virtual" for those methods
where "override" is added. The latter should be enough of an
indication.

As part of this patch, a few minor issues that clang >= 3.5 complains
about are also resolved (unused methods and variables).

misc: Remove redundant compiler-specific defines

This patch moves away from using M5_ATTR_OVERRIDE and the m5::hashmap
(and similar) abstractions, as these are no longer needed with gcc 4.7
and clang 3.1 as minimum compiler versions.

sim: Refactor the serialization base class

Objects that are can be serialized are supposed to inherit from the
Serializable class. This class is meant to provide a unified API for
such objects. However, so far it has mainly been used by SimObjects
due to some fundamental design limitations. This changeset redesigns
to the serialization interface to make it more generic and hide the
underlying checkpoint storage. Specifically:

* Add a set of APIs to serialize into a subsection of the current
object. Previously, objects that needed this functionality would
use ad-hoc solutions using nameOut() and section name
generation. In the new world, an object that implements the
interface has the methods serializeSection() and
unserializeSection() that serialize into a named /subsection/ of
the current object. Calling serialize() serializes an object into
the current section.

* Move the name() method from Serializable to SimObject as it is no
longer needed for serialization. The fully qualified section name
is generated by the main serialization code on the fly as objects
serialize sub-objects.

* Add a scoped ScopedCheckpointSection helper class. Some objects
need to serialize data structures, that are not deriving from
Serializable, into subsections. Previously, this was done using
nameOut() and manual section name generation. To simplify this,
this changeset introduces a ScopedCheckpointSection() helper
class. When this class is instantiated, it adds a new /subsection/
and subsequent serialization calls during the lifetime of this
helper class happen inside this section (or a subsection in case
of nested sections).

* The serialize() call is now const which prevents accidental state
manipulation during serialization. Objects that rely on modifying
state can use the serializeOld() call instead. The default
implementation simply calls serialize(). Note: The old-style calls
need to be explicitly called using the
serializeOld()/serializeSectionOld() style APIs. These are used by
default when serializing SimObjects.

* Both the input and output checkpoints now use their own named
types. This hides underlying checkpoint implementation from
objects that need checkpointing and makes it easier to change the
underlying checkpoint storage code.

mem: adding architectural page table support for SE mode
This patch enables the use of page tables that are stored in system memory
and respect x86 specification, in SE mode. It defines an architectural
page table for x86 as a MultiLevelPageTable class and puts a placeholder
class for other ISAs page tables, giving the possibility for future
implementation.

scons: Add warning for overloaded virtual functions

A derived function with a different signature than a base class
function will result in the base class function of the same name being
hidden. The parameter list and return type for the member function in
the derived class must match those of the member function in the base
class, otherwise the function in the derived class will hide the
function in the base class and no polymorphic behaviour will occur.

This patch addresses these warnings by ensuring a unique function name
to avoid (unintentionally) hiding any functions.

sim: revamp unserialization procedure

Replace direct call to unserialize() on each SimObject with a pair of
calls for better control over initialization in both ckpt and non-ckpt
cases.

If restoring from a checkpoint, loadState(ckpt) is called on each
SimObject. The default implementation simply calls unserialize() if
there is a corresponding checkpoint section, so we get backward
compatibility for existing objects. However, objects can override
loadState() to get other behaviors, e.g., doing other programmed
initializations after unserialize(), or complaining if no checkpoint
section is found. (Note that the default warning for a missing
checkpoint section is now gone.)

If not restoring from a checkpoint, we call the new initState() method
on each SimObject instead. This provides a hook for state
initializations that are only required when *not* restoring from a
checkpoint.

Given this new framework, do some cleanup of LiveProcess subclasses
and X86System, which were (in some cases) emulating initState()
behavior in startup via a local flag or (in other cases) erroneously
doing initializations in startup() that clobbered state loaded earlier
by unserialize().

Syscalls: Make system calls access arguments like a stack, not an array.

When accessing arguments for a syscall, the position of an argument depends on
the policies of the ISA, how much space preceding arguments took up, and the
"alignment" of the index for this particular argument into the number of
possible storate locations. This change adjusts getSyscallArg to take its
index parameter by reference instead of value and to adjust it to point to the
possible location of the next argument on the stack, basically just after the
current one. This way, the rules for the new argument can be applied locally
without knowing about other arguments since those have already been taken into
account implicitly.

All system calls have also been changed to reflect the new interface. In a
number of cases this made the implementation clearer since it encourages
arguments to be collected in one place in order and then used as necessary
later, as opposed to scattering them throughout the function or using them in
place in long expressions. It also discourages using getSyscallArg over and
over to retrieve the same value when a temporary would do the job.

Processes: Make getting and setting system call arguments part of a process object.

This brings M5 closer to modernity - the kernel being advertised is newer so it won't die on binaries compiled with newer glibc's, and enables use of TLS-toolchain built binaries for ALPHA_SE by putting auxiliary vectors on the stack. There are some comments in the code to help. Finally, stats changes for ALPHA are from slight perturbations to the initial stack frame, all minimal diffs.

style: Make a style pass over the whole arch/alpha directory.

Make the process objects use the Params structs in their constructors, and use a limit to check if access are on the stack.

Implement current working directory for LiveProcesses

Finished changing how stat structures are translated, fixed the handling of various ids as LiveProcess parameters.

src/arch/alpha/linux/process.cc:
src/arch/alpha/linux/process.hh:
src/arch/alpha/process.cc:
src/arch/alpha/process.hh:
src/arch/alpha/tru64/process.cc:
src/arch/alpha/tru64/process.hh:
src/arch/mips/linux/process.cc:
src/arch/mips/linux/process.hh:
src/arch/mips/process.cc:
src/arch/mips/process.hh:
src/arch/sparc/linux/process.cc:
src/arch/sparc/linux/process.hh:
src/arch/sparc/process.cc:
src/arch/sparc/process.hh:
src/arch/sparc/solaris/process.cc:
src/arch/sparc/solaris/process.hh:
src/sim/process.cc:
src/sim/process.hh:
src/sim/syscall_emul.cc:
src/sim/syscall_emul.hh:
Changed Process to LiveProcess in syscall handlers and fixed the implementation of uid, euid, gid, egid, pid and ppid as LiveProcess parameters.
src/kern/tru64/tru64.hh:
Changed Process to LiveProcess in syscall handlers and fixed the implementation of uid, euid, gid, egid, pid and ppid as LiveProcess parameters. Also fit tru64 in with the new way to handle stat calls.

Move LiveProcess::create() from arch-specific files
bcak to main LiveProcess, then automatically select
ISA based on object file type. Now simulation scripts
no longer need to care about the ISA, as they can just
call LiveProcess().

configs/test/test.py:
Script no longer cares about ISA.
src/arch/alpha/process.cc:
src/arch/alpha/process.hh:
src/arch/mips/process.cc:
src/arch/mips/process.hh:
src/arch/sparc/process.cc:
src/arch/sparc/process.hh:
src/sim/process.cc:
src/sim/process.hh:
Move create() from arch-specific files back to
main LiveProcess, then automatically select ISA
based on object file type.

Updated Authors from bk prs info

New directory structure:
- simulator source now in 'src' subdirectory
- imported files from 'ext' repository
- support building in arbitrary places, including
outside of the source tree. See comment at top
of SConstruct file for more details.
Regression tests are temporarily disabled; that
syetem needs more extensive revisions.

SConstruct:
Update for new directory structure.
Modify to support build trees that are not subdirectories
of the source tree. See comment at top of file for
more details.
Regression tests are temporarily disabled.
src/arch/SConscript:
src/arch/isa_parser.py:
src/python/SConscript:
Update for new directory structure.