Brad,
So can the boot loader be accessed out of the PIO bus when the address of the PIO and DRAM space are discontinuous? If so, then it should work without Andrew's changes, if not it seems like that should be easy enough to fix because Ruby is sorta skipping that right now anyway? Thanks, Ali On 30.05.2012 17:08, Beckmann, Brad wrote: > Yes, that is correct. Accessing the boot loader out on the PIO bus should work just fine assuming it maps to a different physical address space than DRAM. Also Andrew's observations definitely jive with my expectations. Currently Ruby does not support discontinuous address spaces. > > Brad > >> -----Original Message----- From: [email protected] [2] [mailto:gem5-dev- [email protected] [3]] On Behalf Of Ali Saidi Sent: Friday, May 25, 2012 8:24 AM To: gem5 Developer List Subject: Re: [gem5-dev] Review Request: ARM: Enable Ruby functionality with ARM FS Hi Andrew, The boot loader we used is only a couple of KB, so it doesn't need to be that big, but what I read into Brad's comment was that we could execute the boot loader if it was attached to a ROM outside of main memory as long as we didn't care about the Ruby timing. Brad, did I get that right? In this case couldn't we run the boot loader out of a simple memory connected to a pio bus only use Ruby for the contiguous memory? Thanks, Ali On 5/24/12 6:22 PM, "Andrew Cebulski" <[email protected] [4]> wrote: >> >>> The 172 MB was simply because that's the only way I can see to get Ruby to find the boot loader ROM...by moving it from the higher address space to the lower. I left out that the boot loader ROM is 64MB, therefore I had to shrink the DRAM by 64MB. Basically, it seems Ruby supports multiple contiguous address spaces, just not discontiguous. Is there something I am missing with regards to the ROM...maybe it doesn't need to be 64MB? -Andrew On Thu, May 24, 2012 at 4:01 PM, Ali Saidi <[email protected] [1]> wrote: >>> >>>> On 24.05.2012 15:23, Beckmann, Brad wrote: >>>> >>>>> Sorry for the much >>>> delayed response here. I've been too selective reading the gem5-dev list lately. >>>> >>>>> So if I understand correctly, the ARM FS boot loader maps >>>> to some higher portion of the address space and you would like to model the accesses to this boot loader ROM through Ruby. Is that correct? I'm a bit confused with the comment that the maximum memory supported by Ruby is 172 MB. That certainly is not true. This isn't true, but what I'm not understating is why it was done in the first place. >> that >> >>>> hasn't been fully flushed out. Improving the mapping functions requires better coordination between the python config files and Ruby. I don't have a clear idea of how to do it, but I'm happy to discuss >> ideas. I think most people would be happy in the above worked, although long term that would be a good solution. the response, Ali Brad -----Original Message----- From: Links: ------ [1] mailto:[email protected] [5] [2] http://reviews.gem5.org/r/1191/#review2708 [6] _______________________________________________ gem5-dev mailing list [email protected] [7] http://m5sim.org/mailman/listinfo/gem5-dev [8] _______________________________________________ gem5-dev mailing list [email protected] [9] http://m5sim.org/mailman/listinfo/gem5-dev [10] -- 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. _______________________________________________ gem5-dev mailing list [email protected] [11] > > _______________________________________________ > gem5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/gem5-dev Links: ------ [1] mailto:[email protected] [2] mailto:[email protected] [3] mailto:[email protected] [4] mailto:[email protected] [5] mailto:[email protected] [6] http://reviews.gem5.org/r/1191/#review2708 [7] mailto:[email protected] [8] http://m5sim.org/mailman/listinfo/gem5-dev [9] mailto:[email protected] [10] http://m5sim.org/mailman/listinfo/gem5-dev [11] mailto:[email protected] _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
