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From: Peter Korsgaard <peter@korsgaard.com>
To: buildroot@busybox.net
Subject: [Buildroot] Genimage last partition size issue
Date: Thu, 26 May 2016 21:54:08 +0200	[thread overview]
Message-ID: <87bn3s61en.fsf@dell.be.48ers.dk> (raw)
In-Reply-To: <20160526203517.1a2a3670@free-electrons.com> (Thomas Petazzoni's message of "Thu, 26 May 2016 20:35:17 +0200")

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni@free-electrons.com> writes:

 > Hello,
 > On Tue, 24 May 2016 17:56:50 +0200, Peter Korsgaard wrote:

 >> How should genimage know what the size is of your SD card when you
 >> generate the foo.img image? I guess you would need to add size = 4G
 >> inside image foo.img { }, but notice that this is isn't very efficient
 >> as you will be writing lots of zeros to the sd card.

 > Isn't it possible to generate a sparse file, and then use the sparse
 > capability of dd to avoid writing those lots of zeros?

Can dd detect and do something sensible about sparse files? I thought it
was only able to create sparse files (by seeking)? I would guess you
need a tool that understand the filesystem to know if you can really
skip sequences of zeros when writing.

-- 
Venlig hilsen,
Peter Korsgaard 

  parent reply	other threads:[~2016-05-26 19:54 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-24 15:26 [Buildroot] Genimage last partition size issue Matthew Weber
2016-05-24 15:56 ` Peter Korsgaard
2016-05-26 17:42   ` Matthew Weber
2016-05-26 17:49     ` Gustavo Zacarias
2016-05-26 18:35   ` Thomas Petazzoni
2016-05-26 18:37     ` Gustavo Zacarias
2016-05-26 18:41       ` Thomas Petazzoni
2016-05-26 18:45         ` Gustavo Zacarias
2016-05-26 19:18           ` Thomas Petazzoni
2016-05-26 19:19             ` Gustavo Zacarias
2016-05-26 19:55           ` Peter Korsgaard
2016-05-26 19:54     ` Peter Korsgaard [this message]
2016-05-26 19:59       ` Thomas Petazzoni
2016-05-26 20:05         ` Peter Korsgaard
2016-05-26 21:08           ` Yann E. MORIN

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