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Date: Fri, 27 Nov 2015 09:52:05 +0100
Message-ID: <CAOf5uw==sROkdOU-mEEE2iqBECkX5XcqY_2kNxc1ZJFW+j7niw@mail.gmail.com>
Subject: Re: [PATCH 5/5] arm: boot: store ATAGs structure into DT
 "/chosen/linux,atags" entry
From: Michael Trimarchi <michael@amarulasolutions.com>
To: =?UTF-8?Q?Pali_Roh=C3=A1r?= <pali.rohar@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>, Frank Rowand <frowand.list@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>, Pavel Machek <pavel@ucw.cz>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        Russell King - ARM Linux <linux@arm.linux.org.uk>,
        Laura Abbott <lauraa@codeaurora.org>,
        Grant Likely <grant.likely@linaro.org>,
        Rob Herring <robherring2@gmail.com>, Will Deacon <will.deacon@arm.com>,
        Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>,
        Sebastian Reichel <sre@debian.org>,
        =?UTF-8?Q?Andreas_F=C3=A4rber?= <afaerber@suse.de>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux OMAP Mailing List <linux-omap@vger.kernel.org>
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Hi

On Fri, Nov 27, 2015 at 9:44 AM, Michael Trimarchi
<michael@amarulasolutions.com> wrote:
> Hi
>
> On Fri, Nov 27, 2015 at 9:38 AM, Pali Rohár <pali.rohar@gmail.com> wrote:
>> On Thursday 26 November 2015 12:39:30 Tony Lindgren wrote:
>>> Just to explore options.. How about make a minimal device driver that
>>> just loads the atags blob from /lib/firmware and then shows it in
>>> /proc/atags? Of course some checking on the atags should be done by
>>> the driver..
>>
>> And who can dynamically create that blob file in /lib/firmware? If
>> kernel does not export those atags (somehow) from bootloader, then
>> userspace is not able to create that blob... cyclic problem.
>>
>
> Are those atags from bootloader fix or they change device by device. If they
> are fixed they can be included in some firmware and get from the disk.
>

Sorry, miss the second part of email ;)

Michael

> Michael
>
>> So no, problem is that bootloader provides via custom atags dynamic
>> information like: boot reason (how was device started, by rtc alarm? by
>> reboot? by usb charger? by power button?), boot mode (should be enter
>> into firmware update mode?, is this normal boot mode?), ... and those
>> information are needed for some proprietary software (e.g. firmware
>> upgrade/flash) but also by any other open source applications (based on
>> usb charger we enter different runlevel -- for just only charging
>> device).
>>
>> --
>> Pali Rohár
>> pali.rohar@gmail.com
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
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-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |
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