From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 4 Aug 2015 15:48:00 +0200 From: Gilles Chanteperdrix Message-ID: <20150804134759.GA22015@hermes.click-hack.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Xenomai] Raspberry Pi 2 patch - BCM2709 List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mathieu Cc: xenomai@xenomai.org On Tue, Aug 04, 2015 at 06:30:57AM -0700, Mathieu wrote: > Some status on RPI2: kernel is now booting with CONFIG_IPIPE (only) (at > least passing the interrupt issue). > > The part I was missing is the interrupt binding in > arch_irq_handler_default(). > > I also used the system timer instead of the arm timer. The arm architected timer is used on cortex A15 Processors. So, it can definitely work. > I am not sure the reason but I have the feeling it is because ipipe needs a > oneshot timer. I-pipe does not need a timer. Xenomai does. The ARM architected timer is a oneshot timer, so can be used by Xenomai (and once again, is used on cortex A15). And a periodic timer is not an issue either, provided that you reprogram it at every shot. For details about timers and clocks, once again, see the porting guide. > > I also got the rpi2 connected to a jtag and debugging using eclipse but it > did not help much for this particular issue (and it is rather slow and not > really stable). Yes, in theory JTAG is great, in practice, debug tools are always buggy. Note however that you may have better chances using gdb directly than using eclipse. > > There is a (major) issue: the mmc can not get the clock. > [ 4.108224] mmc-bcm2835 3f300000.mmc: could not get clk > > I am guessing this is due to the switch from ARM timer to system timer. > I will have to fix this eventually (any suggestion welcome). Probable wrong guess. The clock referred to here is a hardware clock (in the sense, an electronic wire which gives a periodic signal), and has nothing to do with the system timer. -- Gilles. https://click-hack.org