Re: [Machinekit] Is there suggested single board computer board for MuliKore use

[schoone...@btinternet.com]

The main features in multicore are only of real use if you are going to be using multiple threads / multiple cores for several processes all accessing the same data. Even then the benefits on a 32bit  architecture processor can be limited. A 32 bit MOV command for instance, is only guaranteed to be atomic, if the memory is naturally aligned on a boundary which is a multiple of 4. Some ARM instructions are also handled differently and some instructions that would be atomic on x86, might not be on ARM. Any instruction to move a 64 bit value on a 32 bit system, is going to involve moving it in 2 sections to two 32 bit registers, which can never be an indivisible atomic operation. All the ARM boards currently in use with Machinekit are 32 bit. Add to this that you need > gcc 4.9 to get near the full C++11 atomic operations standard. Wheezy, backported to 4.7 just scrapes through, but you need a minimum of Jessie and 4.9.2 to use C++11 properly. It is proving a challenge to get BBB users to move off Wheezy despite the fact it is out of all support from Debian in May next year. The fact that the images with 4.x.x kernels do not work because they use xenomai3, does not help. The DE0-NANO is currently approaching end-of-life (in production terms) and I don't know if the FPGA programming works 'as is' with its replacement, or will require changes. They are however still available and have the advantage of being multi-core, of sufficient power and memory (just) to compile their own libraries and Machinekit itself and self-contained. The other option which appears completely overlooked most of the time, is use a proper 64bit computer with a FPGA card. Extremely powerful, fast and flexible. There are quite small form factor PCs around. The alleged 'space saving' often quoted as a reason for SoC boards, is most usually negated by wiring emanating from them that resembles explosions at a spaghetti factory :-) Machinekit is nothing to do with BBB or any other ARM SoC board.  If you have some application that requires to run it to its full potential, with fully atomic operations where possible, that is the answer. regards On 18/07/17 05:48, fairbanks-john wrote: I was going to order a BeagleBone Black (BBB) computer board today but read about MutliKore and put the BeagleBone Black order on hold since I would really like a board that has multiple CPU cores to be able to implement MultiKore features in machinekit. I read that the DE0-NANO-SoC board was being used during testing by at least one tester but would like to know if that is the recommended SBC board or if the development work that has been completed recommends another board to insure compatibility with machinekit. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout. -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to machinekit+unsubscr...@googlegroups.com. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.