From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: BCM2836 (Raspberry Pi 2) port Date: Fri, 24 Apr 2015 12:57:05 -0600 Message-ID: <553A9201.3080308@wwwdotorg.org> References: <1429639796-2169-1-git-send-email-eric@anholt.net> <5539C5A4.5070409@wwwdotorg.org> <87pp6tweql.fsf@eliezer.anholt.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87pp6tweql.fsf-omZaPlIz5HhaEpDpdNBo/KxOck334EZe@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eric Anholt Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Lee Jones , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 04/24/2015 12:41 PM, Eric Anholt wrote: > Stephen Warren writes: > >> On 04/21/2015 12:09 PM, Eric Anholt wrote: >>> This is my first submission of a Raspberry Pi 2 port. It can be found >>> at https://github.com/anholt/linux/tree/bcm2836 >>> >>> I'm using the 2835 interrupt controller support, without adding the >>> checks for ARM local interrupts first. That means no support for IPIs >>> (and thus no SMP), no PMU events, and no local timer (I'm using the >>> same 2835 peripheral one). >>> >>> It supports a similar featureset to Pi 1 at this point. Serial and SD >>> cards work. Just one CPU supported. USB (ethernet) works if you use >>> U-Boot, or my mailbox series >>> (https://github.com/anholt/linux/tree/bcm2836-mbox). >> >> I can't quite get this to work. I think what's happening is that U-Boot >> is over-writing the location of the code/data that the CPU1..3 pin loop >> uses. Do you know what that address is so I can confirm that? >> >> I suspect this because when I load the kernel/DT in U-Boot, or when I >> jump to the kernel to boot it, I see lots of extra duplicated characters >> on the UART, like all 4 CPUs are booting Linux. For example: > > Oops, I was just extrapolating that U-Boot would work. I've quit using > it because of the extra configuration work (particularly the compiled > text files for the boot scripts). You don't need any compiled text files if you create an extlinux.conf rather than a boot.scr. extlinux.conf is plain text. To boot without U-Boot: Could you say what's in your config.txt? I assume I can just copy the kernel zImage as kernel.img, and the DTB from the kernel build tree without renaming it? > I haven't looked into how SMP works, because I don't have the interrupt > support necessary yet (bcm2836-irq branch for hacks in that direction). > > And in further testing, the USB is actually not working and I'm not sure > what gave me the idea that it was. It might be intermittent depending on (GPU) cache content. We need to fix the kernel in a similar fashion to the following U-Boot commits: > http://git.denx.de/?p=u-boot.git;a=commit;h=79340db7f1f676b8eb5911f4993ebedf27009c0b ARM: bcm2835: implement phys_to_bus/bus_to_phys > http://git.denx.de/?p=u-boot.git;a=commit;h=5c0beb5c58c86d2a6d12dee6330dc85554de5c60 usb: dwc2: use phys_to_bus/bus_to_phys > http://git.denx.de/?p=u-boot.git;a=commit;h=122426d46e31391480c4b83b1003e4feca24d491 ARM: bcm2835: use phys_to_bus() for mbox -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html