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From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: BCM2836 (Raspberry Pi 2) port
Date: Fri, 24 Apr 2015 12:57:05 -0600	[thread overview]
Message-ID: <553A9201.3080308@wwwdotorg.org> (raw)
In-Reply-To: <87pp6tweql.fsf@eliezer.anholt.net>

On 04/24/2015 12:41 PM, Eric Anholt wrote:
> Stephen Warren <swarren@wwwdotorg•org> 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

  reply	other threads:[~2015-04-24 18:57 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-21 18:09 BCM2836 (Raspberry Pi 2) port Eric Anholt
2015-04-21 18:09 ` [PATCH 1/9] dt-bindings: Add root properties for Raspberry Pi 2 Eric Anholt
2015-04-24  4:27   ` Stephen Warren
2015-04-21 18:09 ` [PATCH 2/9] ARM: BCM2835: Split peripheral definitions off to a common include Eric Anholt
2015-04-24  4:28   ` Stephen Warren
2015-04-21 18:09 ` [PATCH 3/9] ARM: Make a copy of the 2835 dts for the 2836 Eric Anholt
2015-04-24  4:35   ` Stephen Warren
2015-04-21 18:09 ` [PATCH 4/9] ARM: Update the device trees for 2836 Eric Anholt
2015-04-24  4:36   ` Stephen Warren
2015-04-21 18:09 ` [PATCH 5/9] ARM: BCM2836: Add io map initialization for bcm2836 Eric Anholt
2015-04-21 18:53   ` Arnd Bergmann
2015-04-21 20:37     ` Eric Anholt
2015-04-21 21:11       ` Arnd Bergmann
2015-04-21 23:02         ` Eric Anholt
2015-04-22  7:22           ` Arnd Bergmann
2015-04-24  7:16   ` Arnd Bergmann
2015-04-21 18:09 ` [PATCH 6/9] ARM: Make a Kconfig option for shared BCM2835/BCM2836 code Eric Anholt
2015-04-21 18:09 ` [PATCH 7/9] ARM: Add Kconfig support for bcm2836 Eric Anholt
2015-04-21 18:59   ` Arnd Bergmann
2015-04-21 20:38     ` Eric Anholt
2015-04-24  3:30       ` Stephen Warren
2015-04-21 18:09 ` [PATCH 8/9] ARM: Add MAINTAINERS for 2836 Eric Anholt
2015-04-24  4:38   ` Stephen Warren
2015-04-24 17:03     ` Eric Anholt
2015-04-21 18:09 ` [PATCH 9/9] ARM: BCM283x: Register fixed clocks for uart in the DT Eric Anholt
2015-04-24  4:44   ` Stephen Warren
2015-04-24 17:06     ` Eric Anholt
2015-04-25  4:23       ` Stephen Warren
2015-04-24  4:25 ` BCM2836 (Raspberry Pi 2) port Stephen Warren
2015-04-24 18:41   ` Eric Anholt
2015-04-24 18:57     ` Stephen Warren [this message]
2015-04-27 17:19       ` Eric Anholt
2015-05-08 16:14   ` Alexander Stein
2015-05-12  2:36     ` Stephen Warren
2015-05-12 15:39       ` Alexander Stein
2015-05-12 16:03         ` Stephen Warren
2015-05-12 17:32           ` Eric Anholt
2015-05-12 22:03             ` Stephen Warren
2015-05-13 17:46               ` Eric Anholt
2015-05-13 18:32                 ` Stephen Warren
2015-05-13 18:59                   ` Eric Anholt
2015-04-29  2:38 ` Stephen Warren
2015-04-29  3:41   ` Florian Fainelli
2015-05-06 18:51   ` Eric Anholt
2015-05-06 19:05     ` Arnd Bergmann

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