On Wed, Sep 9, 2015 at 2:54 PM, Sebastian Huber <sebastian.hu...@embedded-brains.de> wrote: > Hello Martin, > > ----- Martin Galvan <martin.gal...@tallertechnologies.com> schrieb: >> Hi there! We were looking at the RTEMS SMP support, and wondered what >> would it take for the system to support some form of memory protection >> (say, an MPU). Is it possible, and if so, how hard would it be? > > the question is, what is "some form of memory protection" for you? > +1. Requirements differ in this space. Note that we do not intend to have supervisor-privilege, so memory protection may be more applicable for safety features or debugging, rather than security. Security is guaranteed only if you can ensure no code injection and you have a trusted code base.
> A process model for RTEMS makes no sense. For this you better use a micro > kernel or Linux. > > The ARMv7-A and some PowerPC BSPs have write protection for code and > read-only data. On some BSPs, read/write to the NULL pointer leads to an > exception. This is quite handy during development, but offers no real > benefit for a production system. > > For one customer we implemented a stack protection, a thread can only access > its own stack, but this is quite non-standard. > >> >> We also saw this: >> >> https://devel.rtems.org/wiki/Projects/MMU_Support >> >> What's the status of this project? > > I don't know. MMU support tends to be highly architecture specific, so the > development of a general purpose API is quite difficult. > I am (as we speak) working on a proposal to look in this direction. I'm happy to talk more or to consider how to align our efforts. >> >> On the other hand, we noticed that LEON3 IP Cores usually implement an >> MMU instead of just an MPU. Would it be feasible to support that? > > The GR740 has an IOMMU (chapter 17). > > http://microelectronics.esa.int/ngmp/GR740-UM-DS-v1.pdf > > -- > Sebastian Huber, embedded brains GmbH > > Address : Dornierstr. 4, D-82178 Puchheim, Germany > Phone : +49 89 189 47 41-16 > Fax : +49 89 189 47 41-09 > E-Mail : sebastian.huber at embedded-brains.de > PGP : Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel