On Tue, 26 Nov 2019 at 21:43, Joel Sherrill <j...@rtems.org> wrote: > > > > On Tue, Nov 26, 2019 at 2:06 PM Niteesh <gsnb...@gmail.com> wrote: >> >> Do both raspberry pi and raspberrypi2 use the same BSP? If not how to build >> for raspberry pi 2 > > > Yes both use the same BSP family with some configuration settings based on > the BSP name/variant. See the configure.ac > > --target=arm-rtems5 --enable-rtemsbsp=raspberrypi2 > >> >> I couldn't find any datasheet's for BCM2711(raspberrypi4), could only find >> for BCM2835 (raspberrypi1): >> https://www.raspberrypi.org/app/uploads/2012/02/BCM2835-ARM-Peripherals.pdf > > > I found this page which links to a preliminary data sheet for the BCM2711 plus > the data sheets for the SoCs the other Pis use. > >> >> but I think we can maybe use the Linux device tree for raspberry pi as a >> reference, >> https://github.com/raspberrypi/linux/blob/rpi-4.19.y/arch/arm/boot/dts/bcm2838.dtsi >> https://github.com/raspberrypi/linux/blob/rpi-4.19.y/arch/arm/boot/dts/bcm2838-rpi-4-b.dts > > > There are BSPs which use device trees now but if the difference is just some > a few base address and > maybe clock settings, I personally wouldn't add device tree support to the > BSP at this point. > >> >> >> >> These are some changes that I found out through google: >> 1) Peripheral base address is now moved to 0x7E000000 >> 2) There's a mention of ARM's GIC400 @ 0x40041000 but probably is only the >> distributor since the old CPU interface is still there @ 0x40000000 > > > These are the type of things you are looking for. What's different. > > It is possible some of the peripherals changed also but maybe not any > impacting being > able to run a basic RTEMS application (console and clock). > The pi4 is pretty similar to pi3 b, console and clock wise they are the same; PL011 or miniuart for console and ARM Generic Timer drivers work unmodified.
> I highly recommend following up in a new thread with a better subject so > people will > recognize it and help. > > Good luck > > --joel > >> >> >> On Tue, Nov 26, 2019 at 7:19 PM Joel Sherrill <j...@rtems.org> wrote: >>> >>> >>> >>> On Tue, Nov 26, 2019 at 5:42 AM Niteesh <gsnb...@gmail.com> wrote: >>>> >>>> Hii, everyone >>>> I am interested in contributing to RTEMS, specifically to the arm based >>>> BSP's. I am a sophomore in electronics and communication engineering >>>> interested in operating systems, and systems programming. I have written >>>> small drivers and libraries for Arduino, bare metal avr chips to interface >>>> with sensors. I would like to take it a bit further by learning about >>>> ARM-based devices. >>>> >>>> I have completed the hello world task for GSOC. As I said early I am >>>> interested in contributing to the drivers and BSP section for most likely >>>> raspberry pi and beaglebone. But I have no idea how to proceed further, >>>> any suggestions on where to start and is it okay to ask tons of questions? >>>> because I had a look at the previous year's project ideas and very little >>>> made sense to me. I am ready to put in my best effort just need some >>>> guidance from your side. >>> >>> >>> This is a hard question to answer. There is a balance of something >>> interesting to do with not sending you on a quest. One extreme would be a >>> full BSP from scratch for some expensive hardware that you don't have and >>> shouldn't even try to afford. The other extreme is something so simple that >>> it isn't interesting. At the same time, it should be useful to the >>> community. >>> >>> I thought a little while about this and think updating the raspberrypi BSP >>> to support the pi3/pi4 should be a useful and tractable BSP issue to >>> address. It is also useful to the community. >>> >>> Discussions when this was brought up before indicate that the precise >>> System on Chip model changed from the 2 to the 3/4 and at least the base >>> address of the UART for the console changed. Getting it working should be a >>> combination of detective work to figure out what precisely changed and fix >>> it along with the possibility of the need for a different device driver on >>> the 3/4. >>> >>> FWIW I noticed that the RSB package qemu4 includes a simulator for the pi2 >>> although I haven't had a chance to see if it works with RTEMS. If it does, >>> that eliminates absolutely needing pi2 hardware. >> >> Can someone provide instruction on the simulator, I searched a lot but found >> no help. >>> >>> >>> >>> Anyway, that's just one idea. It would be useful. >>> >>> Thanks. >>> >>> --joel >>> >>> >>> > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
