From: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> To: Rob Herring <robherring2@gmail.com> Cc: "Jean-Christophe PLAGNIOL-VILLARD" <plagnioj@jcrosoft.com>, "Nicolas Pitre" <nico@fluxnic.net>, "Ivaylo Dimitrov" <ivo.g.dimitrov.75@gmail.com>, "Russell King - ARM Linux" <linux@arm.linux.org.uk>, "Tony Lindgren" <tony@atomide.com>, "Sebastian Reichel" <sre@debian.org>, "Will Deacon" <will.deacon@arm.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "Pavel Machek" <pavel@ucw.cz>, "Pali Rohár" <pali.rohar@gmail.com>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Subject: Re: [PATCH] ARM: /proc/atags: Export also for DT Date: Thu, 29 Jan 2015 02:00:25 +0800 [thread overview] Message-ID: <0ED606B9-34EB-4FEC-BCC1-19BC60BCF768@jcrosoft.com> (raw) In-Reply-To: <CAL_Jsq+rESm8q44ABRbh9hqMsfcMNx0kcXJ5ONbn1=ue-RvHFg@mail.gmail.com> > On Jan 28, 2015, at 11:57 PM, Rob Herring <robherring2@gmail.com> wrote: > > On Wed, Jan 28, 2015 at 8:33 AM, Nicolas Pitre <nico@fluxnic.net> wrote: >> On Wed, 28 Jan 2015, Pali Rohár 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… but if we try to do this generic, where will you store the boot mode I mean where the SoC boot from useful to for the Userspace to known where is the bootloader in case of multi boot mode Best Regards, J. > > Rob > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: plagnioj@jcrosoft.com (Jean-Christophe PLAGNIOL-VILLARD) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] ARM: /proc/atags: Export also for DT Date: Thu, 29 Jan 2015 02:00:25 +0800 [thread overview] Message-ID: <0ED606B9-34EB-4FEC-BCC1-19BC60BCF768@jcrosoft.com> (raw) In-Reply-To: <CAL_Jsq+rESm8q44ABRbh9hqMsfcMNx0kcXJ5ONbn1=ue-RvHFg@mail.gmail.com> > On Jan 28, 2015, at 11:57 PM, Rob Herring <robherring2@gmail.com> 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? but if we try to do this generic, where will you store the boot mode I mean where the SoC boot from useful to for the Userspace to known where is the bootloader in case of multi boot mode Best Regards, J. > > Rob > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2015-01-29 1:07 UTC|newest] Thread overview: 197+ 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 16:54 ` Pali Rohár 2014-06-18 19:01 ` Russell King - ARM Linux 2014-06-18 19:01 ` Russell King - ARM Linux 2014-06-18 19:09 ` Pali Rohár 2014-06-18 19:09 ` Pali Rohár 2014-06-18 19:59 ` Russell King - ARM Linux 2014-06-18 19:59 ` Russell King - ARM Linux 2014-06-19 8:21 ` Pavel Machek 2014-06-19 8:21 ` Pavel Machek 2014-07-11 19:31 ` Pavel Machek 2014-07-11 19:31 ` Pavel Machek 2014-06-18 19:07 ` Rob Herring 2014-06-18 19:07 ` Rob Herring 2014-06-18 19:22 ` Pali Rohár 2014-06-18 19:22 ` Pali Rohár 2014-06-18 20:00 ` Russell King - ARM Linux 2014-06-18 20:00 ` Russell King - ARM Linux 2014-06-18 20:20 ` Pali Rohár 2014-06-18 20:20 ` Pali Rohár 2014-06-18 21:53 ` Fabio Estevam 2014-06-18 21:53 ` Fabio Estevam 2014-11-24 22:16 ` Pali Rohár 2014-11-24 22:16 ` Pali Rohár 2014-06-18 20:46 ` Rob Herring 2014-06-18 20:46 ` Rob Herring 2014-06-18 21:47 ` Russell King - ARM Linux 2014-06-18 21:47 ` Russell King - ARM Linux 2014-06-18 22:27 ` Rob Herring 2014-06-18 22:27 ` Rob Herring 2014-06-18 23:07 ` Russell King - ARM Linux 2014-06-18 23:07 ` Russell King - ARM Linux 2014-11-24 22:19 ` Pali Rohár 2014-11-24 22:19 ` Pali Rohár 2014-12-04 0:33 ` Rob Herring 2014-12-04 0:33 ` Rob Herring 2014-12-04 0:48 ` Pali Rohár 2014-12-04 0:48 ` Pali Rohár 2014-12-04 16:49 ` Rob Herring 2014-12-04 16:49 ` Rob Herring 2014-12-04 17:57 ` Pali Rohár 2014-12-04 17:57 ` Pali Rohár 2014-12-04 18:10 ` Rob Herring 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 19:09 ` Pali Rohár 2015-01-26 20:22 ` Rob Herring 2015-01-26 20:22 ` Rob Herring 2015-01-30 14:14 ` Pali Rohár 2015-01-30 14:14 ` Pali Rohár 2015-01-30 21:03 ` Rob Herring 2015-01-30 21:03 ` Rob Herring 2015-02-27 15:45 ` Pali Rohár 2015-02-27 15:45 ` Pali Rohár 2015-02-27 15:55 ` [PATCH v2 0/2] " Pali Rohár 2015-02-27 15:55 ` 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 ` Pali Rohár 2015-02-27 15:55 ` [PATCH v2 2/2] arm: boot: convert ATAG_REVISION to DT revision field Pali Rohár 2015-02-27 15:55 ` Pali Rohár 2015-03-02 11:28 ` [PATCH v2 0/2] ARM: /proc/cpuinfo: DT: Add support for Revision Pavel Machek 2015-03-02 11:28 ` Pavel Machek 2015-03-16 15:44 ` Tony Lindgren 2015-03-16 15:44 ` Tony Lindgren 2015-03-16 16:14 ` Russell King - ARM Linux 2015-03-16 16:14 ` Russell King - ARM Linux 2015-03-16 16:43 ` Nicolas Pitre 2015-03-16 16:43 ` Nicolas Pitre 2015-03-16 19:21 ` Russell King - ARM Linux 2015-03-16 19:21 ` Russell King - ARM Linux 2015-03-16 18:10 ` Tony Lindgren 2015-03-16 18:10 ` Tony Lindgren 2015-03-16 19:59 ` Russell King - ARM Linux 2015-03-16 19:59 ` Russell King - ARM Linux 2015-03-16 20:54 ` Pali Rohár 2015-03-16 20:54 ` Pali Rohár 2015-03-16 20:59 ` Tony Lindgren 2015-03-16 20:59 ` Tony Lindgren 2015-01-26 22:34 ` [PATCH] " Andreas Färber 2015-01-26 22:34 ` Andreas Färber 2015-02-27 15:56 ` Pali Rohár 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 19:16 ` Pali Rohár 2015-01-26 20:33 ` Rob Herring 2015-01-26 20:33 ` Rob Herring 2015-01-27 13:21 ` Pavel Machek 2015-01-27 13:21 ` Pavel Machek 2015-01-27 14:16 ` Rob Herring 2015-01-27 14:16 ` Rob Herring 2015-01-27 14:24 ` Pavel Machek 2015-01-27 14:24 ` Pavel Machek 2015-01-27 14:32 ` Pali Rohár 2015-01-27 14:32 ` Pali Rohár 2015-01-27 17:48 ` Russell King - ARM Linux 2015-01-27 17:48 ` Russell King - ARM Linux 2015-01-27 20:03 ` Nicolas Pitre 2015-01-27 20:03 ` Nicolas Pitre 2015-01-27 21:09 ` Russell King - ARM Linux 2015-01-27 21:09 ` Russell King - ARM Linux 2015-01-27 21:34 ` Nicolas Pitre 2015-01-27 21:34 ` Nicolas Pitre 2015-01-27 21:58 ` Nicolas Pitre 2015-01-27 21:58 ` Nicolas Pitre 2015-01-27 22:33 ` Russell King - ARM Linux 2015-01-27 22:33 ` Russell King - ARM Linux 2015-01-28 2:07 ` Nicolas Pitre 2015-01-28 2:07 ` Nicolas Pitre 2015-01-28 6:21 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-28 6:21 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-28 7:19 ` Pavel Machek 2015-01-28 7:19 ` Pavel Machek 2015-01-28 8:06 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-28 8:06 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-28 8:25 ` Pavel Machek 2015-01-28 8:25 ` Pavel Machek 2015-01-28 7:18 ` Pavel Machek 2015-01-28 7:18 ` Pavel Machek 2015-01-28 13:38 ` Pali Rohár 2015-01-28 13:38 ` Pali Rohár 2015-01-27 23:10 ` Pavel Machek 2015-01-27 23:10 ` Pavel Machek 2015-01-28 0:50 ` Tony Lindgren 2015-01-28 0:50 ` Tony Lindgren 2015-01-28 13:58 ` Pali Rohár 2015-01-28 13:58 ` Pali Rohár 2015-01-28 14:33 ` Nicolas Pitre 2015-01-28 15:39 ` Tony Lindgren 2015-01-28 15:39 ` Tony Lindgren 2015-01-28 15:47 ` Pali Rohár 2015-01-28 15:47 ` Pali Rohár 2015-01-28 15:48 ` Tony Lindgren 2015-01-28 15:48 ` Tony Lindgren 2015-01-28 16:31 ` Jason Cooper 2015-01-28 16:31 ` Jason Cooper 2015-01-28 15:57 ` Rob Herring 2015-01-28 15:57 ` Rob Herring 2015-01-28 16:13 ` Russell King - ARM Linux 2015-01-28 16:13 ` Russell King - ARM Linux 2015-01-28 16:19 ` Will Deacon 2015-01-28 16:19 ` Will Deacon 2015-01-28 17:01 ` Russell King - ARM Linux 2015-01-28 17:01 ` Russell King - ARM Linux 2015-01-28 17:29 ` Russell King - ARM Linux 2015-01-28 17:29 ` Russell King - ARM Linux 2015-01-28 17:18 ` Pali Rohár 2015-01-28 17:18 ` Pali Rohár 2015-01-28 18:00 ` Jean-Christophe PLAGNIOL-VILLARD [this message] 2015-01-28 18:00 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-28 19:33 ` Pali Rohár 2015-01-28 19:33 ` Pali Rohár 2015-01-28 18:03 ` Pavel Machek 2015-01-28 18:03 ` Pavel Machek 2015-01-28 19:27 ` Arnd Bergmann 2015-01-28 19:27 ` Arnd Bergmann 2015-01-28 14:46 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-28 14:46 ` Jean-Christophe PLAGNIOL-VILLARD 2015-01-27 19:40 ` Nicolas Pitre 2015-01-27 19:40 ` Nicolas Pitre 2015-01-26 20:37 ` Russell King - ARM Linux 2015-01-26 20:37 ` Russell King - ARM Linux 2015-01-26 20:44 ` Pali Rohár 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 19:00 ` Pali Rohár 2014-12-04 10:59 ` Russell King - ARM Linux 2014-12-04 10:59 ` Russell King - ARM Linux 2014-06-18 21:10 ` Aaro Koskinen 2014-06-18 21:10 ` Aaro Koskinen 2014-07-11 19:28 ` Pavel Machek 2014-07-11 19:28 ` Pavel Machek 2014-11-24 22:21 ` Pali Rohár 2014-11-24 22:21 ` Pali Rohár 2014-09-05 11:38 ` Pali Rohár 2014-09-05 11:38 ` Pali Rohár 2014-09-05 12:13 ` Russell King - ARM Linux 2014-09-05 12:13 ` Russell King - ARM Linux 2014-09-10 12:46 ` Pavel Machek 2014-09-10 12:46 ` Pavel Machek 2014-11-24 22:23 ` Pali Rohár 2014-11-24 22:23 ` Pali Rohár 2014-09-05 13:45 ` Mark Rutland 2014-09-05 13:45 ` Mark Rutland 2014-09-05 13:52 ` Pali Rohár 2014-09-05 13:52 ` Pali Rohár 2014-09-05 13:58 ` Mark Rutland 2014-09-05 13:58 ` Mark Rutland 2014-11-24 22:25 ` Pali Rohár 2014-11-24 22:25 ` Pali Rohár 2014-09-05 13:58 ` Fabio Estevam 2014-09-05 13:58 ` Fabio Estevam 2014-11-24 22:27 ` Pali Rohár 2014-11-24 22:27 ` Pali Rohár 2014-09-06 15:34 ` Andreas Färber 2014-09-06 15:34 ` Andreas Färber 2014-11-24 22:29 ` Pali Rohár 2014-11-24 22:29 ` Pali Rohár
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