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== losetup examples ==
{{ToC from="h2" to="h3"}}
=== identify partitions ===
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[~]> fdisk -l kobo.img
Disk kobo.img: 1.9 GiB, 1977614336 bytes, 3862528 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xcee4c14b
Device Boot Start End Sectors Size Id Type
kobo.img1 19456 543744 524289 256M 83 Linux
kobo.img2 543745 1068033 524289 256M 83 Linux
kobo.img3 1068034 3862527 2794494 1.3G b W95 FAT32
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=== available losetup virtual device ===
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[~]> losetup -f
/dev/loop0
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=== count bytes ===
3rd partition starts on 1068034 and one sector has 512 bytes
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[~]> echo 1068034*512 | bc
546833408
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=== attach the partition ===
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[~]> sudo losetup `losetup -f` -o $( echo 1068034*512 | bc ) kobo.img
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=== mount the partition ===
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sudo mount /dev/loop0 /media/
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=== how to attach the middle partition ? ===
The basic idea is:
offset = START * 512
size = ( END - START ) * 512
eg. kobo.img2
SIZE:
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[~]> echo "(1068033-543745)*512" | bc
268435456
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OFFSET:
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[~]> echo 543745*512 | bc
278397440
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so ...
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# losetup `losetup -f ` --offset 278397440 --sizelimit 268435456 kobo.img
# mount /dev/loop0 /media/
# ls /media/
bin dev etc fs.md5sum lib libexec linuxrc lost+found mnt proc root sbin sys tmp upgrade usr var
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=== de attach virtual disk ===
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sudo umount /media
sudo losetup -d /dev/loop0
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