Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Commits on Oct 25, 2012
@andysan arm: Create a GIC base class and make the PL390 derive from it
This patch moves the GIC interface to a separate base class and makes
all interrupt devices use that base class instead of a pointer to the
PL390 implementation. This allows us to have multiple GIC
implementations. Future implementations will allow in-kernel GIC
implementations when using hardware virtualization.

rename : src/dev/arm/ => src/dev/arm/
rename : src/dev/arm/gic.hh => src/dev/arm/gic_pl390.hh
@andysan arm: Don't export private GIC methods 6459908
Commits on Feb 10, 2013
@andysan base: Add support for newer versions of IPython
IPython is used for the interactive gem5 shell if it exists. IPython
made API changes in version 0.11. This patch adds support for IPython
version 0.11 and above.

extra : rebase_source : 5388d0919adb58d97f49a1a637db48cba61283a3
Commits on Feb 11, 2013
Nilay Vaish ruby: record fully busy cycle with in the controller
This patch does several things. First, the counter for fully busy cycles for a
controller is now kept with in the controller, instead of being part of the profiler.
Second, the topology class no longer keeps an array of controllers which was only
used for printing stats. Instead, ruby system will now ask each controller to print
the stats. Thirdly, the statistical variable for recording how many different types
were created is being moved in to the controller from the profiler. Note that for
printing, the profiler will collate results from different controllers.
Nilay Vaish ruby: modifies histogram add() function
This patch modifies the Histogram class' add() function so that it can add
linear histograms as well. The function assumes that the left end point of
the ranges of the two histograms are the same. It also assumes that when
the ranges of the two histogram are changed to accomodate an element not in
the range, the factor used in changing the range is same for both the

This function is then used in removing one of the calls to the global
profiler*. The histograms for recording the delays incurred in processing
different requests are now maintained by the controllers. The profiler
adds these histograms when it needs to print the stats.
Nilay Vaish base: add some mathematical operators to Cycles class affd77e
Nilay Vaish ruby: replaces Time with Cycles in many places
The patch started of with replacing Time with Cycles in the Consumer class.
But to get ruby to compile, the rest of the changes had to be carried out.
Subsequent patches will further this process, till we completely replace
Time with Cycles.
Nilay Vaish ruby: replace Time with Cycles in Message class
Concomitant changes are being committed as well, including the io operator<<
for the Cycles class.
Nilay Vaish ruby: Replace Time with Cycles in SequencerMessage 89f86db
Nilay Vaish ruby: replace Time with Cycles in Memory Controller b742081
Nilay Vaish ruby: replace Time with Cycles in MessageBuffer 5e33045
Nilay Vaish ruby: convert block size, memory size to unsigned 221d392
Nilay Vaish ruby: replace Time with Tick in replacement policy classes 9d6d6c6
Nilay Vaish ruby: replace Time with Cycles in garnet fixed and flexible f6e3ab7
Nilay Vaish ruby: replace Time with Cycles (final patch in the series)
This patch is as of now the final patch in the series of patches that replace
Time with Cycles.This patch further replaces Time with Cycles in Sequencer,
Profiler, different protocols and related entities.

Though Time has not been completely removed, the places where it is in use
seem benign as of now.
Nilay Vaish ruby: enable multiple clock domains
This patch allows ruby to have multiple clock domains. As I understand
with this patch, controllers can have different frequencies. The entire
network needs to run at a single frequency.

The idea is that with in an object, time is treated in terms of cycles.
But the messages that are passed from one entity to another should contain
the time in Ticks. As of now, this is only true for the message buffers,
but not for the links in the network. As I understand the code, all the
entities in different networks (simple, garnet-fixed, garnet-flexible) should
be clocked at the same frequency.

Another problem is that the directory controller has to operate at the same
frequency as the ruby system. This is because the memory controller does
not make use of the Message Buffer, and instead implements a buffer of its
own. So, it has no idea of the frequency at which the directory controller
is operating and uses ruby system's frequency for scheduling events.
Nilay Vaish ruby: MI protocol: add a missing transition
The transition for state MII and event Store was found missing during testing.
The transition is being added. The controller will not stall the Store request
in state MII
Nilay Vaish regressions: update stats due to changes to ruby 1962e92
Commits on Feb 14, 2013
@ahansson-arm ahansson-arm Ruby: Fix compilation errors on gcc 4.7 and clang 3.2
This patch fixes a few (recently added) errors that prevented gem5 from
compiling on more recent versions of gcc and clang.
Commits on Feb 15, 2013
@AGSaidi AGSaidi cpu: Fix a livelock in the o3 cpu.
Check if an instruction just enabled interrupts and we've previously had an
interrupt pending that was not handled because interrupts were subsequently
disabled before the pipeline reached a place to handle the interrupt. In that
case squash now to make sure the interrupt is handled.
@AGSaidi AGSaidi cpu: fix case with o3 cpu blocking and unblocking decode in cycle
Fix a case in the O3 CPU where the decode stage blocks and unblocks in a
single cycle sending both signals to fetch which causes an assert or worse.
The previous check could never work before since the status was set to Blocked
before a test for the status being Unblocking was executed.
@AGSaidi AGSaidi ARM: Fix an issue with clang generating wrong code.
Clang generated executables would enter the if condition when it wasn't
supposted to, resulting in the wrong simulated behavior.
Implementing the operation this way is a bit faster anyway.
@AGSaidi AGSaidi cpu: include set in o3/commit_impl.
While the majority of compilers seemed to pickup set from else where,
one version of gcc 4.7 complains, so explictly add it.
@AGSaidi AGSaidi arm: fix some fp comparisons that worked by accident.
The explict tests in the follwing fp comparison operations were
incorrect as they checked for only signaling NaNs and not quite-NaNs
as well. When compiled with gcc, the comparison generates a fp exception
that causes the FE_INVALID flag to be set and we check for it, so even
though the check was incorrect, the correct exception was set. With clang
this behavior seems to not occur. The checks are updated to test for nans and
the behavior is now correct with both clang and gcc.
@andysan cpu: Add CPU metadata om the Python classes
The configuration scripts currently hard-code the requirements of each
CPU. This is clearly not optimal as it makes writing new configuration
scripts painful and adding new CPU models requires existing scripts to
be updated. This patch adds the following class methods to the base
CPU and all relevant CPUs:

 * memory_mode -- Return a string describing the current memory mode

 * require_caches -- Does the CPU model require caches?

 * support_take_over -- Does the CPU support CPU handover?
@andysan cpu: Make checker CPUs inherit from CheckerCPU in the Python hierarchy
Checker CPUs currently don't inherit from the CheckerCPU in the Python
object hierarchy. This has two consequences:
 * It makes CPU model discovery from the Python world somewhat
   complicated as there is no way of testing if a CPU is a checker.
 * Parameters are duplicated in the checker configuration

This changeset makes all checker CPUs inherit from the base checker
CPU class.
@andysan config: Cleanup CPU configuration
The CPUs supported by the configuration scripts used to be
hard-coded. This was not ideal for several reasons. For example, the
configuration scripts depend on all CPU models even though only a
subset might have been compiled.

This changeset adds a new module to the configuration scripts that
automatically discovers the available CPU models from the compiled
SimObjects. As a nice bonus, the use of introspection allows us to
automatically generate a list of available CPU models suitable for
printing. This list is augmented with the Python doc string from the
underlying class if available.
@andysan config: Move CPU handover logic to m5.switchCpus()
CPU switching consists of the following steps:
 1. Drain the system
 2. Switch out old CPUs (cpu.switchOut())
 3. Change the system timing mode to the mode the new CPUs require
 4. Flush caches if switching to hardware virtualization
 5. Inform new CPUs of the handover (cpu.takeOverFrom())
 6. Resume the system

m5.switchCpus() previously only did step 2 & 5. Since information
about the new processors' memory system requirements is now exposed,
do all of the steps above.

This patch adds automatic memory system switching and flush (if
needed) to switchCpus(). Additionally, it adds optional draining to
switchCpus(). This has the following implications:

* changeToTiming and changeToAtomic are no longer needed, so they have
  been removed.

* changeMemoryMode is only used internally, so it is has been renamed
  to be private.

* switchCpus requires a reference to the system containing the CPUs as
  its first parameter.

WARNING: This changeset breaks compatibility with existing
configuration scripts since it changes the signature of
@andysan config: Remove O3 dependencies
The default cache configuration script currently import the O3_ARM_v7a
model configuration, which depends on the O3 CPU. This breaks if gem5
has been compiled without O3 support. This changeset removes the
dependency by only importing the model if it is requested by the
user. As a bonus, it actually removes some code duplication in the
configuration scripts.
@andysan cpu: Refactor memory system checks
CPUs need to test that the memory system is in the right mode in two
places, when the CPU is initialized (unless it's switched out) and on
a drainResume(). This led to some code duplication in the CPU
models. This changeset introduces the verifyMemoryMode() method which
is called by BaseCPU::init() if the CPU isn't switched out. The
individual CPU models are responsible for calling this method when
resuming from a drain as this code is CPU model specific.
@andysan sim: Add a system-global option to bypass caches
Virtualized CPUs and the fastmem mode of the atomic CPU require direct
access to physical memory. We currently require caches to be disabled
when using them to prevent chaos. This is not ideal when switching
between hardware virutalized CPUs and other CPU models as it would
require a configuration change on each switch. This changeset
introduces a new version of the atomic memory mode,
'atomic_noncaching', where memory accesses are inserted into the
memory system as atomic accesses, but bypass caches.

To make memory mode tests cleaner, the following methods are added to
the System class:

 * isAtomicMode() -- True if the memory mode is 'atomic' or 'direct'.
 * isTimingMode() -- True if the memory mode is 'timing'.
 * bypassCaches() -- True if caches should be bypassed.

The old getMemoryMode() and setMemoryMode() methods should never be
used from the C++ world anymore.
Matt Horsnell o3: fix tick used for renaming and issue with range selection
Fixes the tick used from rename:
- previously this gathered the tick on leaving rename which was always 1 less
  than the dispatch. This conflated the decode ticks when back pressure built
  in the pipeline.
- now picks up tick on entry.

Added --store_completions flag:
- will additionally display the store completion tail in the viewer.
- this highlights periods when large numbers of stores are outstanding (>16 LSQ

Allows selection by tick range (previously this caused an infinite loop)
Sascha Bischoff base: Add warn() and inform() to m5.utils for use from python
This patch adds two fuctions to m5.util, warn and inform, which mirror those
found in the C++ side of gem5. These are added in addition to the already
existing m5.util.panic and m5.util.fatal which already mirror the C++
functionality. This ensures that warning and information messages generated
by python are in the same format as those generated by C++.

Occurrences of
    print "Warning: %s..." % name
have been replaced with
    warn("%s...", name)
@ahansson-arm ahansson-arm mem: Tighten up cache constness and scoping
This patch merely adopts a more strict use of const for the cache
member functions and variables, and also moves a large portion of the
member functions from public to protected.
Chris Emmons ARM: Postpones creation of framebuffer output file until it is actual…
…ly used.

This delay prevents a potential conflict with the HDLCD if both are in the same
system even if only one is enabled.
Geoffrey Blake cpu: Fix rename mis-handling serializing instructions when resource c…

The rename can mis-handle serializing instructions (i.e. strex) if it gets
into a resource constrained situation and the serializing instruction has
to be placed on the skid buffer to handle blocking.  In this situation the
instruction informs the pipeline it is serializing and logs that the next
instruction must be serialized, but since we are blocking the pipeline
defers this action to place the serializing instruction and
incoming instructions into the skid buffer. When resuming from blocking,
rename will pull the serializing instruction from the skid buffer and
the current logic will see this as the "next" instruction that has to
be serialized and because of flags set on the serializing instruction,
it passes through the pipeline stage as normal and resets rename to
non-serializing.  This causes instructions to follow the serializing inst
incorrectly and eventually leads to an error in the pipeline. To fix this
rename should check first if it has to block before checking for serializing
Geoffrey Blake cpu: Avoid duplicate entries in tracking structures for writes to mis…
…c regs

setMiscReg currently makes a new entry for each write to a misc reg without
checking for duplicates, this can cause a triggering of the assert if an
instruction get replayed and writes to the same misc regs multiple times.
This fix prevents duplicate entries and instead updates the value.
@andysan dev: Use the correct return type for disk offsets
Replace the use of off_t in the various DiskImage related classes with
std::streampos. off_t is a signed 32 bit integer on most 32-bit
systems, whereas std::streampos is normally a 64 bit integer on most
modern systems. Furthermore, std::streampos is the type used by
tellg() and seekg() in the standard library, so it should have been
used in the first place. This patch makes it possible to use disk
images larger than 2 GiB on 32 bit systems with a modern C++ standard
@andysan cpu: Document exec trace flags 3af59ab
Mrinmoy Ghosh arm: fix a page table walker issue where a page could be translated m…
…ultiple times

If multiple memory operations to the same page are miss the TLB they are
all inserted into the page table queue and before this change could result
in multiple uncessesary walks as well as duplicate enteries being inserted
into the TLB.
@AGSaidi AGSaidi stats: update regressions for o3 changes in renaming and translation. bd31a5d
Anthony Gutierrez ext lib: add libfdt to enable flattened device tree support
this patch adds libfdt, a library necessary for supporting
flattened device tree support in current and future versions of
the linux/android kernel for ARM.
Anthony Gutierrez loader: add a flattened device tree blob (dtb) object
this adds a dtb_object so the loader can load in the dtb
file for linux/android ARM kernels.
Anthony Gutierrez options: add command line option for dtb file 21aa950
Commits on Feb 19, 2013
Andreas Hansson mem: Ensure trace captures packet fields before forwarding
This patch fixes a bug in the CommMonitor caused by the packet being
modified before it is captured in the trace. By recording the fields
before passing the packet on, and then putting these values in the
trace we ensure that even if the packet is modified the trace captures
what the CommMonitor saw.
@ahansson-arm ahansson-arm base: Fix a bug in the address interleaving
This patch fixes a minor (but important) typo in the matching of an
address to an interleaved range.
@ahansson-arm ahansson-arm mem: Add predecessor to SenderState base class
This patch adds a predecessor field to the SenderState base class to
make the process of linking them up more uniform, and enable a
traversal of the stack without knowing the specific type of the

There are a number of simplifications done as part of changing the
SenderState, particularly in the RubyTest.
Sascha Bischoff mem: Fix SenderState related cache deadlock
This patch fixes a potential deadlock in the caches. This deadlock
could occur when more than one cache is used in a system, and
pkt->senderState is modified in between the two caches. This happened
as the caches relied on the senderState remaining unchanged, and used
it for instantaneous upstream communication with other caches.

This issue has been addressed by iterating over the linked list of
senderStates until we are either able to cast to a MSHR* or
senderState is NULL. If the cast is successful, we know that the
packet has previously passed through another cache, and therefore
update the downstreamPending flag accordingly. Otherwise, we do
@ahansson-arm ahansson-arm x86: Move APIC clock divider to Python
This patch moves the 16x APIC clock divider to the Python code to
avoid the post-instantiation modifications to the clock. The x86 APIC
was the only object setting the clock after creation time and this
required some custom functionality and configuration. With this patch,
the clock multiplier is moved to the Python code and the objects are
instantiated with the appropriate clock.
@ahansson-arm ahansson-arm sim: Make clock private and access using clockPeriod()
This patch makes the clock member private to the ClockedObject and
forces all children to access it using clockPeriod(). This makes it
impossible to inadvertently change the clock, and also makes it easier
to transition to a situation where the clock is derived from e.g. a
clock domain, or through a multiplier.
@ahansson-arm ahansson-arm mem: Add deferred packet class to prefetcher
This patch removes the time field from the packet as it was only used
by the preftecher. Similar to the packet queue, the prefetcher now
wraps the packet in a deferred packet, which also has a tick
representing the absolute time when the packet should be sent.
@ahansson-arm ahansson-arm mem: Make packet bus-related time accounting relative
This patch changes the bus-related time accounting done in the packet
to be relative. Besides making it easier to align the cache timing to
cache clock cycles, it also makes it possible to create a Last-Level
Cache (LLC) directly to a memory controller without a bus inbetween.

The bus is unique in that it does not ever make the packets wait to
reflect the time spent forwarding them. Instead, the cache is
currently responsible for making the packets wait. Thus, the bus
annotates the packets with the time needed for the first word to
appear, and also the last word. The cache then delays the packets in
its queues before passing them on. It is worth noting that every
object attached to a bus (devices, memories, bridges, etc) should be
doing this if we opt for keeping this way of accounting for the bus
@ahansson-arm ahansson-arm mem: Change accessor function names to match the port interface
This patch changes the names of the cache accessor functions to be in
line with those used by the ports. This is done to avoid confusion and
get closer to a one-to-one correspondence between the interface of the
memory object (the cache in this case) and the port itself.

The member function timingAccess has been split into a snoop/non-snoop
part to avoid branching on the isResponse() of the packet.
@ahansson-arm ahansson-arm mem: Enforce strict use of busFirst- and busLastWordTime
This patch adds a check to ensure that the delay incurred by
the bus is not simply disregarded, but accounted for by someone. At
this point, all the modules do is to zero it out, and no additional
time is spent. This highlights where the bus timing is simply dropped
instead of being paid for.

As a follow up, the locations identified in this patch should add this
additional time to the packets in one way or another. For now it
simply acts as a sanity check and highlights where the delay is simply

Since no time is added, all regressions remain the same.
@ahansson-arm ahansson-arm scons: Fix up numerous warnings about name shadowing
This patch address the most important name shadowing warnings (as
produced when using gcc/clang with -Wshadow). There are many
locations where constructor parameters and function parameters shadow
local variables, but these are left unchanged.
@ahansson-arm ahansson-arm scons: Add warning for missing field initializers
This patch adds a warning for missing field initializers for both gcc
and clang, and addresses the warnings that were generated.
@ahansson-arm ahansson-arm 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.
@ahansson-arm ahansson-arm scons: Add warning for overloaded virtual functions
Fix the ISA startup warnings
@ahansson-arm ahansson-arm scons: Add warning for missing declarations
This patch enables warnings for missing declarations. To avoid issues
with SWIG-generated code, the warning is only applied to non-SWIG
@ahansson-arm ahansson-arm scons: Add warning delete with non-virtual destructor
This patch enables a warning for deleting derived classes that do not
have a virtual destructor. The patch merely adds additional checks,
and there are currently no cases that had to be fixed.
@ahansson-arm ahansson-arm scons: Unify the flags shared by gcc and clang
This patch restructures and unifies the flags used by gcc and clang as
they are largely the same. The common parts are now dealt with in a
shared block of code, and the few bits and pieces that are
specifically affecting either gcc or clang are done separately.
@ahansson-arm ahansson-arm scons: Fix warnings issued by clang 3.2svn (XCode 4.6)
This patch fixes the warnings that clang3.2svn emit due to the "-Wall"
flag. There is one case of an uninitialised value in the ARM neon ISA
description, and then a whole range of unused private fields that are
Ali Saidi stats: more zizzer stats fun a86f67e
@ahansson-arm ahansson-arm mem: Fix sender state bug and delay popping
This patch fixes a newly introduced bug where the sender state was
popped before checking that it should be. Amazingly all regressions
pass, but Linux fails to boot on the detailed CPU with caches enabled.
Commits on Feb 20, 2013
Nilay Vaish ruby: remove unused variable m_print_config in class Topology e95e78f
Nilay Vaish slicc: remove unused variable message_buffer_names fea27bc
Ali Saidi config: Fix --prog-interval command line option 82cf156
Commits on Feb 28, 2013
Dibakar Gope ext:( ruby: mesi coherence protocol: invalidate lock
The MESI CMP directory coherence protocol, while transitioning from SM to IM,
did not invalidate the lock that it might have taken on a cache line. This
patch adds an action for doing so.

The problem was found by Dibakar, but I was not happy with his proposed
solution. So I implemented a different solution.

Committed by: Nilay Vaish <>
Commits on Mar 01, 2013
@ahansson-arm ahansson-arm mem: Merge ranges in bus before passing them on
This patch adds basic merging of address ranges to the bus, such that
interleaved ranges are merged together before being passed on by the
bus. As such, the bus aggregates the address ranges of the connected
slave ports and then passes on the merged ranges through its master
ports. The bus thus hides the complexity of the interleaved ranges and
only exposes contigous ranges to the surrounding system.

As part of this patch, the bus ranges are also cached for any future
@ahansson-arm ahansson-arm mem: Merge interleaved ranges when creating backing store
This patch adds merging of interleaved ranges before creating the
backing stores. The backing stores are always a contigous chunk of the
address space, and with this patch it is possible to have interleaved
memories in the system.
@ahansson-arm ahansson-arm mem: Add support for multi-channel DRAM configurations
This patch adds support for multi-channel instances of the DRAM
controller model by stripping away the channel bits in the address
decoding. The patch relies on the availiability of address
interleaving and, at this time, it is up to the user to configure the
interleaving appropriately. At the moment it is assumed that the
channel interleaving bits are immediately following the column bits
(smallest sensible interleaving). Convenience methods for building
multi-channel configurations will be added later.
@ahansson-arm ahansson-arm mem: SimpleDRAM variable naming and whitespace fixes
This patch fixes a number of small cosmetic issues in the SimpleDRAM
module. The most important change is to move the accounting of
received packets to after the check is made if the packet should be
retried or not. Thus, packets are only counted if they are actually
@ahansson-arm ahansson-arm stats: Update stats to reflect SimpleDRAM changes
This patch bumps the stats to reflect the slight change in how the
retry is handled, and also the pruning of some redundant stats.
@ahansson-arm ahansson-arm mem: Add a method to build multi-channel DRAM configurations
This patch adds a class method that allows easy creation of
channel-interleaved multi-channel DRAM configurations. It is enabled
by a class method to allow customisation of the class independent of
the channel configuration. For example, the user can create a MyDDR
subclass of e.g. SimpleDDR3, and then create a four-channel
configuration of the subclass by calling MyDDR.makeMultiChannel(4,
mem_start, mem_size).
@ahansson-arm ahansson-arm mem: Add check if SimpleDRAM nextReqEvent is scheduled
This check covers a case where a retry is called from the SimpleDRAM
causing a new request to appear before the DRAM itself schedules a
nextReqEvent. By adding this check, the event is not scheduled twice.
Commits on Mar 03, 2013
Nilay Vaish sim: remove duplicate check on stack size a4e8512
Blake Hechtman ext:( ruby: fixes functional writes to RubyRequest
The functional write code was assuming that all writes are block sized,
which may not be true for Ruby Requests. This bug can lead to a buffer

Committed by: Nilay Vaish <>
Commits on Mar 05, 2013
Ali Saidi ARM: fix some cases where instructions that write to fp reg 15 are ac…
…cidently branches.
Ali Saidi cpu: fix a switching issue with the o3 cpu.
This change fixes the switcheroo test that broke earlier this month. The code
that was checking for the pipeline being blocked wasn't checking for a pending
translation, only for a icache access.
Ali Saidi stats: update patches for branch predictor and fetch updates. 09b2430
Commits on Mar 07, 2013
Nilay Vaish ruby: garnet: fixed: implement functional access e8802fa
Nilay Vaish ruby: remove the functional copy of memory in se mode
This patch removes the functional copy of the memory that was maintained in
the se mode. Now ruby itself will provide the data.
Nilay Vaish regressions: stats updates due to no physmem in ruby d24d544
@ahansson-arm ahansson-arm x86: Make the table walker reset the packet delay
This patch fixes an issue related to the table walker recycling
packets that still have a bus delay that is not accounted for. For
now, we simply ignore the values and reset them to zero.
@ahansson-arm ahansson-arm ruby: Fix gcc 4.8 maybe-uninitialized compilation error
This patch fixes the one-and-only gcc 4.8 compilation error, being a
warning about "maybe uninitialized" in Orion.
@ahansson-arm ahansson-arm base: Fix address range granularity calculations
This patch fixes a bug in the address range granularity
calculations. Previously it incorrectly used the high bit to establish
the size of the regions created, when it should really be looking at
the low bit.
Commits on Mar 11, 2013
Nilay Vaish x86: implement some of the x87 instructions
This patch implements ftan, fprem, fyl2x, fld* floating-point instructions.
Nilay Vaish regressions: x86: stats updates due to new x87 insts 53a0597