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Turns out that SPARC SE mode relied on M5_pid being "0" in all cases. The entries in the SPARC TLBs are accessed with M5_pid as their context. This is buggy in the sense that it will never work with more than one process or any initialization that doesn't have the M5_pid value passed in as "0". cd7f3a1dbf55 broke the SPARC build because it deletes M5_pid and uses a _pid with a default of "100" instead. This caused the SPARC TLB to never return any valid lookups for any request; the program never moved past the first instruction with SPARC SE in the regression tester. The solution proposed in this changeset is to initialize the address space identification register with the PID value that is passed into the process class as a parameter from Python. This should return the correct responses from the TLB since the insertions and lookups into the page table will be using the same PID. Furthermore, there are corner cases in the code which elevate privileges and revert to using context "0" as the context in the TLB. I believe that these are related to kernel level traps and hypervisor privilege escalations, but I'm not completely sure. I've tried to address the corner cases properly, but it would be beneficial to have someone who is familiar with the SPARC architecture to take a look at this fix.
This is the gem5 simulator. The main website can be found at http://www.gem5.org A good starting point is http://www.gem5.org/Introduction, and for more information about building the simulator and getting started please see http://www.gem5.org/Documentation and http://www.gem5.org/Tutorials. To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/Dependencies for more details concerning the minimum versions of the aforementioned tools. Once you have all dependencies resolved, type 'scons build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS, POWER, SPARC, or X86. This will build an optimized version of the gem5 binary (gem5.opt) for the the specified architecture. See http://www.gem5.org/Build_System for more details and options. With the simulator built, have a look at http://www.gem5.org/Running_gem5 for more information on how to use gem5. The basic source release includes these subdirectories: - configs: example simulation configuration scripts - ext: less-common external packages needed to build gem5 - src: source code of the gem5 simulator - system: source for some optional system software for simulated systems - tests: regression tests - util: useful utility programs and files To run full-system simulations, you will need compiled system firmware (console and PALcode for Alpha), kernel binaries and one or more disk images. Please see the gem5 download page for these items at http://www.gem5.org/Download If you have questions, please send mail to gem5-users@gem5.org Enjoy using gem5 and please share your modifications and extensions.