> On 13 Feb 2018, at 5:37 pm, Christian Mauderer > <christian.maude...@embedded-brains.de> wrote: > >> Am 13.02.2018 um 00:34 schrieb Chris Johns: >>> On 13/02/2018 00:39, Christian Mauderer wrote: >>> These patches add various improvements for the atsam BSP and for the >>> sc16is752 SPI UART controller. >>> >>> Regarding patch 1: Note that I have thought about an auto detection >>> instead of the option. But I had a board where something responded to >>> the oscillator so that I could initialize it despite the fact that no >>> crystall has been connected. So I think an auto detection would be >>> dangerous. >> >> I agree with this approach. >> >> Auto-detection is OK in systems with users however in embedded systems it is >> dangerous. I have a rule, any auto-detection requires a system level module >> that >> audits the part of a system that has auto-detection and raises any unexpected >> differences as errors. Auto-detection can be hard to avoid in some systems, >> ie >> PC motherboards, PCI etc. >> >> I remember back in the mid-90s working on an important system with RAM size >> detection where one of two static RAM chips had started to fail and the >> system >> adjusted assuming this was all the available memory so no one noticed until >> many >> many months into operation the application was reconfigured and it ran out of >> memory when it should not have. At the start of the project I had been asked >> to >> add the memory detection to handle different build variants of the hardware. >> The >> feature was disabled and I have not been a fan of it ever since. >> >> Chris >> > > Hello Chris, > > thanks for the support for this approach. I mostly wanted to give a > reason why I thought it would be necessary to add another option to the BSP. > > Any other remarks regarding the patches? Can I apply them? >
Yes, they look fine. I do not know the hardware so I assume that part is fine. Chris _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
