The components in base/loader were moved into a namespace called
Loader. This will make it easier to add loader components with fairly
short natural names which don't invite name collisions.
gem5 should use namespaces more in general for that reason and to make
it easier to write independent components without having to worry about
name collisions being added in the future.
Unfortunately this namespace has the same name as a class used to load
an object file into a process object. These names can be disambiguated
because the Process loader is inside the Process scope and the Loader
namespace is at global scope, but it's still confusing to read.
Fortunately, this shouldn't last for very long since the responsibility
for loading Processes is going to move to a fake OS object which will
expect to load a particular type of Process, for instance, fake 64 bit
x86 linux will load either 32 or 64 bit x86 processes.
That means that the capability to feed any binary that matches the
current build into gem5 and have gem5 figure out what to do with it
will likely be going away in the future. That's likely for the best,
since it will force users to be more explicit about what they're trying
to do, ie what OS they want to try to load a given binary, and also
will prevent loading two or more Processes which are for different OSes
to the same system, something that's possible today as far as I know
since there are no consistency checks.
Change-Id: Iea0012e98f39f5e20a7c351b78cdff9401f5e326
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24783
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This generalized Workload SimObject is not geared towards FS or SE
simulations, although currently it's only used in FS. This gets rid
of the ARM specific highestELIs64 property (from the workload, not the
system) and replaces it with a generic getArch.
The old globally accessible kernel symtab has been replaced with a
symtab accessor which takes a ThreadContext *. The parameter isn't used
for anything for now, but in cases where there might be multiple
symbol tables to choose from (kernel vs. current user space?) the
method will now be able to distinguish which to use. This also makes
it possible for the workload to manage its symbol table with whatever
policy makes sense for it.
That method returns a const SymbolTable * since most of the time the
symbol table doesn't need to be modified. In the one case where an
external entity needs to modify the table, two pseudo instructions,
the table to modify isn't necessarily the one that's currently active.
For instance, the pseudo instruction will likely execute in user space,
but might be intended to add a symbol to the kernel in case something
like a module was loaded.
To support that usage, the workload has a generic "insertSymbol" method
which will insert the symbol in the table that "makes sense". There is
a lot of ambiguity what that means, but it's no less ambiguous than
today where we're only saved by the fact that there is generally only
one active symbol table to worry about.
This change also introduces a KernelWorkload SimObject class which
inherits from Workload and adds in kernel related members for cases
where the kernel is specified in the config and loaded by gem5 itself.
That's the common case, but the base Workload class would be used
directly when, for instance, doing a baremetal simulation or if the
kernel is loaded by software within the simulation as is the case for
SPARC FS.
Because a given architecture specific workload class needs to inherit
from either Workload or KernelWorkload, this change removes the
ability to boot ARM without a kernel. This ability should be restored
in the future.
To make having or not having a kernel more flexible, the kernel
specific members of the KernelWorkload should be factored out into
their own object which can then be attached to a workload through a
(potentially unused) property rather than inheritance.
Change-Id: Idf72615260266d7b4478d20d4035ed5a1e7aa241
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24283
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
