In case a workload is run with no bootloader we still want to be able
to provide the simulation with the correct arch version.
Without this patch every baremetal simulation will default to AArch64, which
is the default value of ArmFsWorkload.
Change-Id: I0f766167d8983cafc1fd30d054862339eb21f73f
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26606
Reviewed-by: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
While the up-to-date data may reside in any agent of Ruby's memory
hierarchy, there's an optional backing store in Ruby that provides
a 'correct' view of the physical memory. When it is enabled by the
user, every Ruby memory access will update this global memory view
as well upon finishing.
The issue is that Ruby's atomic access, used in fast-forward, does
not currently access the backing store, leading to data
incorrectness. More specifically, at the very beginning stage of the
simulation, a loader loads the program into the backing store using
functional accesses. Then the program starts execution with
fast-forward enabled, using atomic accesses for faster simulation. But
because atomic access only accesses the real memory hierarchy, the CPU
fetches incorrect instructions.
The fix is simple. Just make Ruby's atomic access update the backing
store as well as the real physical memory.
Change-Id: I2541d923e18ea488d383097ca7abd4124e47e59b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26343
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Onur Kayıran <onur.kayiran@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This flag makes constructing a generic Request object for ARM
impossible, since generic consumers won't know to set that flag to one.
As a principle, Request flags should change the behavior of a request
away from whatever the default/typical behavior is in the current
context, so flags set to zero means no special behavior.
Change-Id: Id606dc0bf42210218e1745585327671a98a8dba4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26546
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This is a reduced model of the FVP Base platforms Power Controller.
As of now it allows the following functions from software:
- Checking for core presence
- Reporting the power state of a core / cluster
- Explicitly powering off a core on WFI
- Explicitly powering off cores in a CPU cluster on WFI
- Explicitly powering on a core through writes to PPONR register
Change-Id: Ia1d4d3ae8e4bfb2d23b2c6077396a4d8500e2e30
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26463
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This method can be used for allocating resources for registers and/or
arguments, but it can also be used for generic preparation for them
as well. For instance, it can be used to detect some sort of property
of the function signature as a whole (if it's variadic for instance)
which can be stored in position and used to change ABI behavior.
Change-Id: I8a090be65dc4987e35cd115562114cd1b748155f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24106
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This header was getting pretty long, and could be broken up into a few
headers which logically grouped related definitions and concepts.
To maintain compatibility and keep things simple for users of the
mechanism, there is still a top level header with the original name
which defines the interface for using ABIs. It includes all the other
new headers, and so can also be used when defining ABIs.
Change-Id: I62a051b9bd982e0fcecfceeb3d658d1ff4d30c5e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24104
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
This change generalizes the GuestABI Result template family's
allocate() mechanism so that it can also be used with arguments. This
is useful in cases like the 32 bit ARM ISA which says that variadic
functions treat their floating point arguments differently than
non-variadic functions do. This mechanism will give the ABI a chance
to detect that the function is variadic (by checking for VarArgs) and
then to behave differently in that case.
This also makes the GuestABI mechanism a little more regular by
supporting allocate() on both arguments and return values instead of
just return values.
Change-Id: I67050a0ad7ccf15ee75b800dca4eae4fdc0e564e
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24103
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
This implementation has been tested a tiny bit by intercepting a call
which passed an argument of this type to a function.
struct Test
{
int32_t a;
float *b;
};
The gem5 intercept printed out the value of a, the value of b, and the
value of the float it pointed to.
I was able to get things to work by commenting out the panic in
fixFuncEventAddr and making it return its argument unmodified, and by
calling addFuncEvent instead of addKernelFuncEvent which injects the
kernel symbol table. I substitured the Process's debugSymbolTable which
had the right symbols.
Note that this implementation is not completely correct. First of all,
I used a dummy type in place of the Short Vector type which is just
a byte array with the appropriate alignment forced on it. It sounds
like this type would be something the compiler would need an intrinsic
and architecture specific type for to behave correctly, and so in
gem5 we'd have to define our own type for ARM which could feed in here.
Also, strictly speaking, it sounds like HVA and HFA category of types,
the Homogeneous Short-Vector Aggregates and Homogeneous Floating-point
Aggregates, are supposed to apply to any type which is an aggregate of
all the same type (short vector for one, floating point for the other)
with 4 or fewer members.
In this implementation, I capture any *array* of 4 or fewer elements of
the appropriate type as an HVA or HFA, but I believe these structures
would also count and are not included in my implementation.
struct {
float a;
float b;
float c;
};
struct {
ShortVector a;
ShortVector b;
};
This only matters if those sorts of structures are passed by value as
top level arguments to a function, ie they are not included in some
larger structure.
Also, rule B.6 talks about what to do with an "aignment adjusted type",
and I have no idea what that's supposed to be. Those may not be handled
correctly either.
Change-Id: I5a599a03d38075d7c0a06988c05e7fb5423c68c0
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23751
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
The pseudo instruction implementation is very short, and so doing the
work it was doing directly doesn't really add much to the
implementation of the udelay events. By not calling the pseudo
instruction we also uncouple these unrelated mechanisms and don't,
for instance, cause pseudo instruction debug output every time udelay
executes.
Change-Id: I5c9b32509562487e53b2acfa1a3f6226d33d1cfd
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23748
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
This method lets system call implementations return values into
ThreadContexts other than the one they were called from. That's useful
for, for instance, clone() which creates new ThreadContexts.
By making it a virtual function in the SyscallDesc, we can delegate the
actual implementation to the SyscallDescABI subclass which knows the
ABI and how to use it to set the return value.
Change-Id: I61c6e60e4c2a8863c885cd818e4ff053fc3312ee
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23503
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
The definition of ioctl is not actually variadic, it just doesn't
specify what the type of the pointer is that it takes as its third
argument. The man page says that that's because it predates void *
being valid C.
By passing this address around (even if it's unused), we avoid having
to extract system call arguments further down the call stack.
Change-Id: I62541237baafaec30bbe3df06b3284dd286a4051
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23456
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Having readable constants for these large numbers is good, but they
used incorrect style, were at global scope, and were only used in one
place.
This change centralizes them where they're used, fixes their style, and
rewrites the actual constants in a way that makes it clear what they're
values are.
Change-Id: Ib89c46fce133d4180296d384a61d51d1fe1f8d20
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23455
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
These are "integer" registers which are renamed, but which aren't
normally considered integer registers by the ISA. They had been indexed
by adding an opaque constant to the number of official integer
registers which obscured what they were, and was also fragile and
invited mistakes.
Change-Id: Idab8cf4d889682b98c7c81a00d9a92d8e3bb3a05
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23445
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These ABIs (one 32 bit and one 64 bit) take advantage of the
GenericSyscallABI and X86Linux::SyscallABI partial ABIs set up earlier.
This removes x86's dependence on the getSyscallArg and setSyscallReturn
Process methods.
Change-Id: Ia07834cea1afa827d77e590af5397e2a1e0e2099
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23443
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
It's very common for system call arguments to be passed in a sequence
of registers, one argument per register. To avoid having that
implementation repeated over and over across the various ISAs and OSes,
these partial ABI implementations provide that mechanism they can just
pull in. They would need to define the sequence of registers to use,
and these would take care of the rest.
Unlike the temporary DefaultSyscallABI which defers to the Process
classes, these read registers from the ThreadContext directly.
Change-Id: Ic72eb8d784ecf4711b5eec76d958a87c70850fce
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23441
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
When the new thread context ctc is created, it should have a copy of
all the state in the original tc, including the original PC. This code
used to specially handle the KVM case by explicitly making this new
context return from the system call immediately by jumping right to
RCX which (assuming a particular instruction was used) is where user
mode should resume.
The first problem with this approach as far as I can tell is that the
CPU will still be in CPL0, ie supervisor mode, and will not have been
forced back into CPL3, ie user mode. This may not have any immediately
visible effect, but may down the line.
Second, this seems unnecessary. The non-special case code will advance
the PC beyond the instruction which triggered the system call. Then
once the new thread starts executing again, it will execute sysret and
return to rcx naturally, just like the original thread will.
The only observed difference is that when executing a gem5 instruction,
the IP is set to the currently executing instruction, and so to avoid
the new context from re-executing the system call, the PC needs to be
advanced. When calling in from KVM, the instruction has already been
"completed", and so the IP should *not* be advanced.
Also note that when reading the PCState object in KVM, it doesn't
figure out where the next instruction is and so NPC is just one
ExtMachInst sized blob later on. Advancing the PC will just move to
an address 8 bytes later, which is very unlikely to be what you want.
Jira Issue: https://gem5.atlassian.net/browse/GEM5-187
Change-Id: I0d97f66e64ce39b13d6700dcf3d7da88d6fe0048
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23199
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
