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From: Wojciech Kromer <wojciech.kromer@dgt•com.pl>
To: linuxppc-embedded@ozlabs•org
Subject: Re: Upgrading cramfs root file system
Date: Fri, 21 Apr 2006 08:42:01 +0200	[thread overview]
Message-ID: <44487EB9.6090600@dgt.com.pl> (raw)
In-Reply-To: <20060420221801.55331e15@White64>

Dnia 2006-04-20 22:18, Użytkownik White napisał:
> make it easy: if you start an application which do the flash and after
> this a reset.. nothing should happen. I do it that way.
> the application resist completly in RAM .. and all important libs are
> in RAm or in Filesystem Cache.
> It's only important that you pretend any Application from accessing
> Datafiles or start of new application ...
>
> Alternativly, you can put it in a reserved RAM Area ( mark it not
> usable by Linux) and put a Flash Code in your Bootloader (U-boot?)
> after a reset....
>
> But overwrite a cramfs works for me on >100 times without problems.
>
>   

Problems with changing cramfs  and reboot may vary depending on changes 
made to filesystem.
You can't even call reboot, bacause it's not in the prevoius location 
after changing flash.

> Am Thu, 20 Apr 2006 21:54:45 +0200 schrieb Antonio Di Bacco
> <antonio.dibacco@aruba•it> :
>
>   
>> Yes you are right, it is not a good idea to overwrite working cramfs 
>> filesystem. But what happens if I download the new cramfs plus kernel in RAM, 
>> do a checksum and then, completely in kernel mode, disabling all the 
>> interrupts, I write to flash? No process could complain that I am overwriting 
>> because no one is executing.
>>
>>     
Maybe such feature should be added to MTD code.
But disabling interrupts may cause watchdog reset in most embedded 
platforms.

      parent reply	other threads:[~2006-04-21  6:42 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-04-06 20:38 Upgrading cramfs root file system Antonio Di Bacco
2006-04-19  7:42 ` Wojciech Kromer
2006-04-20 19:54   ` Antonio Di Bacco
2006-04-20 20:18     ` White
2006-04-20 21:03       ` Upgrading cramfs root file system while running (DENX wrote that is not possible) Antonio Di Bacco
2006-04-20 21:08         ` Antonio Di Bacco
2006-04-21  4:10         ` Tolunay Orkun
2006-04-21  5:51           ` antonio.dibacco
2006-04-21 16:57             ` Wolfgang Denk
2006-04-22 19:07               ` Tolunay Orkun
2006-04-21 16:55           ` Wolfgang Denk
2006-04-22 18:50             ` Tolunay Orkun
2006-04-21  6:53         ` David Jander
2006-04-21 20:23           ` Wolfgang Denk
2006-04-21 21:32             ` Antonio Di Bacco
2006-04-22 11:40               ` Stefan Eletzhofer
2006-04-22 19:21                 ` Upgrading cramfs root file system while running (DENX wrote that is not possible)I Antonio Di Bacco
2006-04-22 19:53               ` Upgrading cramfs root file system while running (DENX wrote that is not possible) Tolunay Orkun
     [not found]       ` <20060420211120.GA3546@mail.gnudd.com>
2006-04-20 21:37         ` Antonio Di Bacco
2006-04-21  6:42       ` Wojciech Kromer [this message]

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