I have not run it under linux on pi2 yet. Will have to run and check the result. On 2 Jun 2015 16:16, "Joel Sherrill" <joel.sherr...@oarcorp.com> wrote:
> > > On June 2, 2015 5:58:33 AM EDT, Rohini Kulkarni <krohini1...@gmail.com> > wrote: > >HI, > > > >I tried running the dhrystone benchmark with some changes for cache/mmu > >set up. > > > >However, the output shows a reduction in performance. > >The time to run through the dhrystone has increased from 12 to 13 and > >dhrystones run per second decreased. > > > >According to this result, things were better with caches disabled. > > > > > >I have been working on this since two days and could not figure out an > >improvement. Any pointers? > > How did it do under Linux on the Pi2? > > > >Thanks. > > > > > > > >On Thu, May 28, 2015 at 8:41 PM, Rohini Kulkarni > ><krohini1...@gmail.com> wrote: > > > >Hi All, > > > >I have to implement the cache coherency support for Cortex A7. But for > >A7 MPCore, unlike for A9, I am not able to find any register > >description for the Snoop Control Unit from the TRM. > > > >I need help here on how to proceed. > > > >Additionally for A9 there is a single bit for A9 in the Auxiliary > >Control Register which enables cache broadcast operations. The register > >format is different for A7 and again I am unable to find how to achieve > >the same for A7. > > > >Thanks! > > > > > > > > > > > >On Tue, May 5, 2015 at 10:42 PM, Joel Sherrill > ><joel.sherr...@oarcorp.com> wrote: > > > > > > > >On 5/5/2015 11:11 AM, Rohini Kulkarni wrote: > > > >Hi, > > > >I am working with the code for bsp hooks. I am referring to existing > >ARM multicore bsp codes, zync mainly. > > > >1. There are existing hooks for the raspberry pi. Where should the code > >for the Pi2 hooks be added? > > > >The Pi and Pi2 are remarkably similar so Pi2 should be placed inside > >the Pi BSP directory. > >There is already a Pi2 variant of that code built. But we know specific > >places where there > >are variances. Depending on the scope of what is different, it can be > >as simple as > >a cpp conditional in a .h to select a value or two implementations of a > >single method > >and the Makefile.am picking the right file to build based on the board > >variant. > > > >The big question to always ask is: Is this specific to the Pi2 and > >incompatible with the Pi? > > > >Since the Pi BSP is still missing capabilities, it is likely code > >common to both will > >be added this summer. For example, did the mailbox interface change? I > >don't know > >but would guess that it didn't. Each new capability added needs that > >added. > > > >And any differences need to be analyzed to pick the least intrusive way > >to provide > >alternate implementations. Or enable special code like the Pi2 SMP > >support which > >is dependent on --enable-smp and being a Pi2. > > > >2. Am I right in understanding that I will have to implement A7 > >specific functions as have been for A9? I am referring specifically to > >the arm-a9mpcore-start.h > > > >Yes. > > > >If the code is very similar between the a7 and a9, then a discussion > >on devel@ should occur to decide the best way to minimize duplication. > > > >If you end up with a7 specific code, you should follow the location and > > > >naming patterns already established. That places it in > >libbsp/arm/shared/... > >so it can be used by any BSP with the right SMP core. > > > > > >I am referring to existing codes to locate and get hold of what needs > >to be done in the hooks. However, being new to such implementations, I > >am taking longer to understand the details. Any suggestions that might > >help here are welcome > > > >The answer will depend on the factors listed above. When code can > >be shared, we want to share it across as many BSPs as makes sense. > >When it is unique to a specific BSP **variant** (e.g. Pi vs Pi2), then > >you want to find the way to account for the variation in the least > >intrusive code way possible. > > > >Thanks! > > > >On 1 May 2015 12:45, "Rohini Kulkarni" <krohini1...@gmail.com> wrote: > > > > > >Hi, > > > >Excited to be a part of this edition of GSoC! Thanks to everybody for > >helping me get here and congratulations to all the participating > >students! > > > >So, now getting to work, firstly I wish to know, specifically from my > >mentors, any changes that must be made to my proposed project or > >schedule. > > > >Secondly, are there any specifics for the development blog that we need > >to create for the project? Over time what is the blog expected to > >convey. > > > >Also, I have to create a new wiki page for my project as none exists. I > >want to know how to add one. > > > >-- > > > >Rohini Kulkarni > > > > > >-- Joel Sherrill, Ph.D. Director of Research & Development > >joel.sherr...@oarcorp.com On-Line Applications Research Ask me about > >RTEMS: a free RTOS Huntsville AL 35805 Support Available (256) 722-9985 > > > > > > > > > > > >-- > > > >Rohini Kulkarni > > > > > > > > > >-- > > > >Rohini Kulkarni > > --joel >
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