From: pali.rohar@gmail.com (Pali Rohár)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: /proc/atags: Export also for DT
Date: Wed, 28 Jan 2015 18:18:12 +0100 [thread overview]
Message-ID: <201501281818.12121@pali> (raw)
In-Reply-To: <CAL_Jsq+rESm8q44ABRbh9hqMsfcMNx0kcXJ5ONbn1=ue-RvHFg@mail.gmail.com>
On Wednesday 28 January 2015 16:57:18 Rob Herring wrote:
> On Wed, Jan 28, 2015 at 8:33 AM, Nicolas Pitre
<nico@fluxnic.net> wrote:
> > On Wed, 28 Jan 2015, Pali Roh?r wrote:
> >> On Wednesday 28 January 2015 01:50:33 Tony Lindgren wrote:
> >> > On omaps, the bootrom passes the bootreason in r1 to the
> >> > bootloader that can do whatever it wants with it. We
> >> > could maybe pass it in the kernel cmdline to the
> >> > watchdog driver for user space?
> >>
> >> Not truth for N900. Bootreason depends on PRM_RSTST omap
> >> register, state of vbat charger pins, time how long was
> >> power key pressed, R&D data stored in CAL partition and
> >> other undocumented registers for omap HS devices. I
> >> already tried to implement at least some subset of it in
> >> userspace (or kernel), but it is impossible because NOLO
> >> bootloader clear status of PRM_RSTST register.
> >>
> >> There is also copy of PRM_RSTST register stored at address
> >> 0x4020FFB8 (tracing data) but that address is rewritten
> >> (probably by kernel), so we really cannot implement
> >> reading bootreason in kernel.
> >>
> >> But in early stage in uboot it is possible to read
> >> 0x4020FFB8 address and get some part of bootreason. But
> >> still PRM_RSTST is not enough!
> >>
> >> I would be happy if DT kernel can export /proc/atags file
> >> with ATAGs passed by bootloader. It would be enough for
> >> me. In userspace I can parse content and do what is
> >> needed.
> >
> > What about defining a DT boot reason property instead?
> > Maybe it already exists? If not, it's something that could
> > certainly be generically used on other platforms too.
>
> I'm fine with that, but we just need to have a standard kernel
> userspace interface in addition to something like
> /proc/device-tree/bootreason. Perhaps this can be the default
> implementation for the watchdog dev. Someday when we decide DT
> is crap and have a new boot interface, we'll have people
> relying on /proc/device-tree. I hope to be retired when that
> happens...
>
> Rob
Then what about exporting bootreason as /proc/bootreason?
--
Pali Roh?r
pali.rohar at gmail.com
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next prev parent reply other threads:[~2015-01-28 17:18 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-18 16:54 [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible Pali Rohár
2014-06-18 19:01 ` Russell King - ARM Linux
2014-06-18 19:09 ` Pali Rohár
2014-06-18 19:59 ` Russell King - ARM Linux
2014-06-19 8:21 ` Pavel Machek
2014-07-11 19:31 ` Pavel Machek
2014-06-18 19:07 ` Rob Herring
2014-06-18 19:22 ` Pali Rohár
2014-06-18 20:00 ` Russell King - ARM Linux
2014-06-18 20:20 ` Pali Rohár
2014-06-18 21:53 ` Fabio Estevam
2014-11-24 22:16 ` Pali Rohár
2014-06-18 20:46 ` Rob Herring
2014-06-18 21:47 ` Russell King - ARM Linux
2014-06-18 22:27 ` Rob Herring
2014-06-18 23:07 ` Russell King - ARM Linux
2014-11-24 22:19 ` Pali Rohár
2014-12-04 0:33 ` Rob Herring
2014-12-04 0:48 ` Pali Rohár
2014-12-04 16:49 ` Rob Herring
2014-12-04 17:57 ` Pali Rohár
2014-12-04 18:10 ` Rob Herring
2015-01-26 19:09 ` [PATCH] ARM: /proc/cpuinfo: DT: Add support for Revision Pali Rohár
2015-01-26 20:22 ` Rob Herring
2015-01-30 14:14 ` Pali Rohár
2015-01-30 21:03 ` Rob Herring
2015-02-27 15:45 ` Pali Rohár
2015-02-27 15:55 ` [PATCH v2 0/2] " Pali Rohár
2015-02-27 15:55 ` [PATCH v2 1/2] arm: devtree: Set system_rev from DT revision Pali Rohár
2015-02-27 15:55 ` [PATCH v2 2/2] arm: boot: convert ATAG_REVISION to DT revision field Pali Rohár
2015-03-02 11:28 ` [PATCH v2 0/2] ARM: /proc/cpuinfo: DT: Add support for Revision Pavel Machek
2015-03-16 15:44 ` Tony Lindgren
2015-03-16 16:14 ` Russell King - ARM Linux
2015-03-16 16:43 ` Nicolas Pitre
2015-03-16 19:21 ` Russell King - ARM Linux
2015-03-16 18:10 ` Tony Lindgren
2015-03-16 19:59 ` Russell King - ARM Linux
2015-03-16 20:54 ` Pali Rohár
2015-03-16 20:59 ` Tony Lindgren
2015-01-26 22:34 ` [PATCH] " Andreas Färber
2015-02-27 15:56 ` Pali Rohár
2015-01-26 19:16 ` [PATCH] ARM: /proc/atags: Export also for DT Pali Rohár
2015-01-26 20:33 ` Rob Herring
2015-01-27 13:21 ` Pavel Machek
2015-01-27 14:16 ` Rob Herring
2015-01-27 14:24 ` Pavel Machek
2015-01-27 14:32 ` Pali Rohár
2015-01-27 17:48 ` Russell King - ARM Linux
2015-01-27 20:03 ` Nicolas Pitre
2015-01-27 21:09 ` Russell King - ARM Linux
2015-01-27 21:34 ` Nicolas Pitre
2015-01-27 21:58 ` Nicolas Pitre
2015-01-27 22:33 ` Russell King - ARM Linux
2015-01-28 2:07 ` Nicolas Pitre
2015-01-28 6:21 ` Jean-Christophe PLAGNIOL-VILLARD
2015-01-28 7:19 ` Pavel Machek
2015-01-28 8:06 ` Jean-Christophe PLAGNIOL-VILLARD
2015-01-28 8:25 ` Pavel Machek
2015-01-28 7:18 ` Pavel Machek
2015-01-28 13:38 ` Pali Rohár
2015-01-27 23:10 ` Pavel Machek
2015-01-28 0:50 ` Tony Lindgren
2015-01-28 13:58 ` Pali Rohár
2015-01-28 14:33 ` Nicolas Pitre
2015-01-28 15:39 ` Tony Lindgren
2015-01-28 15:47 ` Pali Rohár
2015-01-28 15:48 ` Tony Lindgren
2015-01-28 16:31 ` Jason Cooper
2015-01-28 15:57 ` Rob Herring
2015-01-28 16:13 ` Russell King - ARM Linux
2015-01-28 16:19 ` Will Deacon
2015-01-28 17:01 ` Russell King - ARM Linux
2015-01-28 17:29 ` Russell King - ARM Linux
2015-01-28 17:18 ` Pali Rohár [this message]
2015-01-28 18:00 ` Jean-Christophe PLAGNIOL-VILLARD
2015-01-28 19:33 ` Pali Rohár
2015-01-28 18:03 ` Pavel Machek
2015-01-28 19:27 ` Arnd Bergmann
2015-01-28 14:46 ` Jean-Christophe PLAGNIOL-VILLARD
2015-01-27 19:40 ` Nicolas Pitre
2015-01-26 20:37 ` Russell King - ARM Linux
2015-01-26 20:44 ` Pali Rohár
2014-12-04 19:00 ` [PATCH] ARM: /proc/cpuinfo: Use DT machine name when possible Pali Rohár
2014-12-04 10:59 ` Russell King - ARM Linux
2014-06-18 21:10 ` Aaro Koskinen
2014-07-11 19:28 ` Pavel Machek
2014-11-24 22:21 ` Pali Rohár
2014-09-05 11:38 ` Pali Rohár
2014-09-05 12:13 ` Russell King - ARM Linux
2014-09-10 12:46 ` Pavel Machek
2014-11-24 22:23 ` Pali Rohár
2014-09-05 13:45 ` Mark Rutland
2014-09-05 13:52 ` Pali Rohár
2014-09-05 13:58 ` Mark Rutland
2014-11-24 22:25 ` Pali Rohár
2014-09-05 13:58 ` Fabio Estevam
2014-11-24 22:27 ` Pali Rohár
2014-09-06 15:34 ` Andreas Färber
2014-11-24 22:29 ` Pali Rohár
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