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From: Nikita Kiryanov <nikita@compulab.co.il>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 0/5] Create an API for safely accessing BMP header fields
Date: Tue, 05 Feb 2013 09:22:35 +0200	[thread overview]
Message-ID: <5110B33B.50200@compulab.co.il> (raw)
In-Reply-To: <5110AC6D.7050901@compulab.co.il>

On 02/05/2013 08:53 AM, Igor Grinberg wrote:
> On 02/04/13 13:39, Nikita Kiryanov wrote:
>> When configuring U-Boot to display a splash image, the user is free to
>> designate whatever address they see fit as the in-memory location of BMP
>> file. Unfortunately, this makes it easy to place the BMP header fields in
>> unaligned addresses, which will cause a data abort on architectures which
>> can't handle unaligned memory accesses. What's worse, addresses which are
>> supposed to be issue free (32 bit aligned addresses) actually don't work
>> because of the structure of the BMP header file (the header starts with 2
>> chars, followed by __u32 fields. The two chars offset the 32 bit fields away
>> from proper alignment).
>>
>> As a result, it is very easy to brick the board that U-Boot runs on with certain
>> architectures. Once a bad address for splash image is selected and the board
>> restarted, U-Boot never reaches command line, and yet the only way to prevent
>> the data aborts from happening is to clear or change the environment variable
>> splashimage.
>>
>> While it is possible to fix the problem by compiling all relevant files with
>> $(PLATFORM_NO_UNALIGNED), it is possible to handle it with finer granularity by
>> creating an API for header accesses, and compiling only that with
>> $(PLATFORM_NO_UNALIGNED).
>>
>> This patchset creates such an API, and makes use of it wherever an in-memory BMP
>> header is probed for data.
>>
>> Further information can be found in this discussion:
>> http://lists.denx.de/pipermail/u-boot/2013-January/144666.html
>>
>> Nikita Kiryanov (5):
>>    Add bmp_layout module for accessing BMP header data
>>    lcd: use bmp_layout API
>>    cmd_bmp: use bmp_layout API
>>    video/cfb_console: use bmp_layout API
>>    video/bus_vcxk: use bmp_layout API
>
> In 5 above patches, Nikita has accidentally added my s-o-b,
> without me being participating in the patch development or delivery
> process.
> Nikita, please, don't do so in the future.
>
> Thanks.
>

I apologize. It won't happen again.

-- 
Regards,
Nikita.

      reply	other threads:[~2013-02-05  7:22 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-04 11:39 [U-Boot] [PATCH 0/5] Create an API for safely accessing BMP header fields Nikita Kiryanov
2013-02-04 11:39 ` [U-Boot] [PATCH 1/5] Add bmp_layout module for accessing BMP header data Nikita Kiryanov
2013-02-04 19:26   ` Wolfgang Denk
2013-02-04 21:26     ` Albert ARIBAUD
2013-02-04 23:11       ` Wolfgang Denk
2013-02-05  8:07         ` Igor Grinberg
2013-02-05  9:57           ` Wolfgang Denk
2013-02-05 11:38             ` Igor Grinberg
2013-02-05 13:20               ` Wolfgang Denk
2013-02-05 14:49                 ` Igor Grinberg
2013-02-05 19:27                   ` Wolfgang Denk
2013-02-05  6:52     ` Nikita Kiryanov
2013-02-05  9:47       ` Wolfgang Denk
2013-02-04 11:39 ` [U-Boot] [PATCH 2/5] lcd: use bmp_layout API Nikita Kiryanov
2013-02-04 11:39 ` [U-Boot] [PATCH 3/5] cmd_bmp: " Nikita Kiryanov
2013-02-04 11:39 ` [U-Boot] [PATCH 4/5] video/cfb_console: " Nikita Kiryanov
2013-02-04 11:39 ` [U-Boot] [PATCH 5/5] video/bus_vcxk: " Nikita Kiryanov
2013-02-04 11:57 ` [U-Boot] [PATCH 0/5] Create an API for safely accessing BMP header fields Albert ARIBAUD
2013-02-04 12:37   ` Nikita Kiryanov
2013-02-04 14:19     ` Albert ARIBAUD
2013-02-04 15:07       ` Nikita Kiryanov
2013-02-04 15:25         ` Albert ARIBAUD
2013-02-04 20:48           ` Wolfgang Denk
2013-02-05  7:20           ` Nikita Kiryanov
2013-02-04 20:39       ` Wolfgang Denk
2013-02-05 14:58       ` Tom Rini
2013-02-05 19:37         ` Albert ARIBAUD
2013-02-04 20:35     ` Wolfgang Denk
2013-02-04 21:02       ` Jeroen Hofstee
2013-02-05  7:39         ` Igor Grinberg
2013-02-05  6:53 ` Igor Grinberg
2013-02-05  7:22   ` Nikita Kiryanov [this message]

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