From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: Multi-platform, and secure-only ARM errata workarounds
Date: Wed, 27 Feb 2013 10:42:27 -0700 [thread overview]
Message-ID: <512E4583.4080609@wwwdotorg.org> (raw)
In-Reply-To: <22709540.96uJddbx1U@fb07-iapwap2.physik.uni-giessen.de>
On 02/27/2013 02:03 AM, Marc Dietrich wrote:
> Am Dienstag, 26. Februar 2013, 09:39:15 schrieb Stephen Warren:
>> On 02/26/2013 02:36 AM, Marc Dietrich wrote:
>>> Am Montag, 25. Februar 2013, 16:47:38 schrieb Stephen Warren:
>>>> ...
>>>> Now, I can easily add those 3 errata workarounds to U-Boot, but that
>>>> will require people to reflash their bootloader. This is probably
>>>> acceptable for development/reference boards (although I'm sure people
>>>> will find it annoying) but for re-purposed production boards (such as
>>>> the Toshiba AC100 or various tablets) it will be impossible to update
>>>> the factory bootloader. Switching to upstream U-Boot would currently
>>>> lose some functionality, and significantly affect people's boot flow, so
>>>> is likely unacceptable.
>>>
>>> personally, I have no problem to require a certain u-boot version for a
>>> given kernel. From a distro point of view, you will likely update the
>>> bootloader/kernel on a distro update anyway.
>>
>> So a distro will certainly update the kernel.
>>
>> But updating a bootloader would be very unusual, I believe.
>
> mmh? Every time I update to a new distro release, the bootloader gets also
> updated - even on arm, e.g. ftp://ports.ubuntu.com/ubuntu-ports/pool/main/u/u-boot-linaro lists four version of uboot - one for each supported distro
> release. I know for closed embedded device this is different, but that's not
> our target.
I have no idea why that package exists or what it is. It clearly doesn't
install U-Boot on the device when the package is installed, or anyone
using an AC100 would already be running U-Boot not our binary
bootloader, right?
>> Also, I hope that upstream U-Boot is never going to support the bizarre
>> "Tegra partition table" cruft that our "fastboot" bootloader supports,
>> so you'll end up completely re-programming the flash (BCT, bootloader,
>> partition table, all filesystems) if you want to switch to U-Boot. That
>> seems like a fair chunk for the installer to own, but I guess if you're
>> comfortable with doing that, I won't complain.
>
> Yes, that a huge pile of work and people are working on this already. One the
> other hand, why (if not for upgrade use) do we have u-boot support for all
> these legacy boards?
Mainly because I didn't want to use our binary bootloader when
developing or testing kernel support for the AC100, I think:-)
But yes, I would support all AC100 general Linux usage switching to U-Boot.
I think what I'll do when Tegra is converted to multi-platform is:
a) The WARs will be disabled in the kernel; no choice there really.
b) I've already submitted patches to U-Boot to implement the WARs there.
c) Everyone will need to update to the latest U-Boot:-(
d) For people wanting to continue running our binary bootloader (which
only implements 1 of the 3 WARs in question in the latest code, and I
have no idea if it even did that when the AC100 bootloader binary was
compiled), they'll need to create a small stub binary that implements
the WARs and prepend this to the zImage. I can help create this if
people need. Or, you can chain-load U-Boot. I've filed bugs against our
binary bootloader, so hopefully within a few years or something, new
products won't need this stub!
next prev parent reply other threads:[~2013-02-27 17:42 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-25 23:47 Multi-platform, and secure-only ARM errata workarounds Stephen Warren
2013-02-26 9:36 ` Marc Dietrich
2013-02-26 16:39 ` Stephen Warren
2013-02-26 22:31 ` Nicolas Pitre
2013-02-27 9:03 ` Marc Dietrich
2013-02-27 14:00 ` Rob Herring
2013-02-27 17:42 ` Stephen Warren [this message]
2013-02-28 13:58 ` Marc Dietrich
2013-02-26 10:23 ` Arnd Bergmann
2013-02-26 10:31 ` Catalin Marinas
2013-02-26 10:35 ` Catalin Marinas
2013-02-26 10:48 ` Arnd Bergmann
2013-02-26 11:11 ` Catalin Marinas
2013-02-26 11:35 ` Russell King - ARM Linux
2013-02-26 14:07 ` Rob Herring
2013-02-26 18:01 ` Stephen Warren
2013-02-26 18:11 ` Russell King - ARM Linux
2013-02-26 18:30 ` Stephen Warren
2013-02-26 18:49 ` Russell King - ARM Linux
2013-02-27 6:07 ` Santosh Shilimkar
2013-03-01 17:37 ` Stephen Warren
2013-03-01 18:05 ` Russell King - ARM Linux
2013-03-04 6:34 ` Peter De Schrijver
2013-03-04 9:16 ` Peter De Schrijver
2013-03-04 17:08 ` Stephen Warren
2013-03-05 7:40 ` Peter De Schrijver
2013-03-05 17:00 ` Stephen Warren
2013-03-06 8:14 ` Peter De Schrijver
2013-03-06 16:18 ` Stephen Warren
2013-03-10 17:25 ` Santosh Shilimkar
2013-03-10 18:47 ` Olof Johansson
2013-03-11 16:59 ` Stephen Warren
2013-03-11 18:54 ` Jason Gunthorpe
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