[PATCH 5/5] arm: boot: store ATAGs structure into DT "/chosen/linux,atags" entry

Michael Trimarchi michael at amarulasolutions.com
Fri Nov 27 00:52:05 PST 2015


Hi

On Fri, Nov 27, 2015 at 9:44 AM, Michael Trimarchi
<michael at amarulasolutions.com> wrote:
> Hi
>
> On Fri, Nov 27, 2015 at 9:38 AM, Pali Rohár <pali.rohar at 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 at gmail.com
>> --
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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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