Hi Abdul, This will cause lots of other problems.
You need a new class ExternalMemory or similar, that inherits from AbstractMemory, but allows you to hook in an external port, much like the ExternalSlave. The crux is that AbstractMemory comes with a number of assumptions that your external memory has to live up to. The actual backingstore has to be contiguous in host memory, and you need to be able to present a pointer to this memory. Andreas From: gem5-users <gem5-users-boun...@gem5.org<mailto:gem5-users-boun...@gem5.org>> on behalf of Abdul Mutaal <abdul.mut...@gmail.com<mailto:abdul.mut...@gmail.com>> Reply-To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> Date: Wednesday, 5 August 2015 10:15 To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> Subject: Re: [gem5-users] Gem5 ATAG error Hi Andreas, Thanks for your reply. I just created a SimpleMemory object in MemConfig and gave it the ranges of external memory. That's resolved the issue. I don't know if it is the right solution. Thanks 2015-08-03 14:56 GMT+02:00 Andreas Hansson <andreas.hans...@arm.com<mailto:andreas.hans...@arm.com>>: Hi Abdul, This touches on a pretty fundamental issue. The external port works fine for connecting devices, but when connecting a memory, there are a number of assumptions in gem5 that will give us problems. You have run into the first one which is that gem5 needs to be aware of the memory to report it to the OS. The external memory would thus have to be a subclass of AbstractMemory. Similarly, gem5 assumes that you can get a pointer into the actual backing store for the memory. This is used by functional accesses (only Alpha and X86 afaik) while the system is running. It is also used to support switching to/from KVM. I am not sure how to solve this. Again, if you subclass the AbstractMemory for your exernal memory, this should be ok. Ultimately I think the best way forward is to create an ExternalMemory wrapper, similar to ExternalSlave, but also exposing the underlying memory and address ranges. Andreas From: gem5-users <gem5-users-boun...@gem5.org<mailto:gem5-users-boun...@gem5.org>> on behalf of Abdul Mutaal <abdul.mut...@gmail.com<mailto:abdul.mut...@gmail.com>> Reply-To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> Date: Monday, 3 August 2015 13:41 To: "m5-us...@m5sim.org<mailto:m5-us...@m5sim.org>" <m5-us...@m5sim.org<mailto:m5-us...@m5sim.org>> Subject: [gem5-users] Gem5 ATAG error Dear Community, I am facing an error in full system simulation regarding ATAG. The exact error is fatal: Expected a single ATAG memory entry but got 0 @ tick 0 The scenario is that I am booting ICS image on gem5 with external memory (don't want to use dram). As far I understood the system.cc doesn't find the range of physcial memory. Is that true? are there any other reasons for this error? Also I run the same configuration with memory controller with SimpleMemory. It works fine. Thanks -- Regards, Abdul Mutaal -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England & Wales, Company No: 2557590 ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England & Wales, Company No: 2548782 _______________________________________________ gem5-users mailing list gem5-users@gem5.org<mailto:gem5-users@gem5.org> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users -- Regards, Abdul Mutaal -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England & Wales, Company No: 2557590 ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England & Wales, Company No: 2548782
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