how do i open/edit a rasberry image?

[andrew R]

i have googled the heck out of this so please forgive me if this is a no brainer...

i have downloaded rasberry images from various distributions and would like to
open an image on my laptop to make adjustments before i boot the rasberry itself.

i get the following error when i try to mount an image on my laptop:

mount 2012-08-08-wheezy-armel.img /mnt -o loop
mount: unknown filesystem type '(null)'
mount 2012-08-08-wheezy-armel.img /mnt
mount: unknown filesystem type '(null)'

i get this error across the board with every distribution.

i cant make my edits on a running rasberry because the change i need is to set up the
rasberry serial console from the boot line (i have no keyboard, screen or mouse) so no
rasberry until i get this working.

maybe my kernel needs an option i don’t have? here is my laptop environment:-

cat /etc/issue
Welcome to openSUSE 12.2 "Mantis" - Kernel \r (\l).

uname -a
Linux linux-ywym.site 3.4.6-2.10-desktop #1 SMP PREEMPT Thu Jul 26 09:36:26 UTC 2012 (641c197) i686 i686 i386 GNU/Linux

how do i mount a rasberry image (either on the sd card or as an image) on my laptop??

thanks

andrew.

[redhawk]

Does this help?? - http://en.wikibooks.org/wiki/QEMU/Image ... n_the_host

If that doesn't work then I guess you'll have to flash an SD Card and mount it on the Raspberry PI via a USB memory card reader.
Once you have edited what it required you extract an image file back from the SD Card.

It maybe possible to avoid flashing if you use the image file as a secondary hard drive with Win32 Qemu running Raspberry Pi or a Live Linux distro like Mint.

Richard S.

[rurwin]

@redhawk, the problem with that is that you would need to know the offset to the second partition. Theoretically that is not impossible, but I don't know how to do it.

I think the problem you are seeing is that the image includes the partition table and two partitions, whereas the filesystem drivers expect to see single partitions.

Why can you not write the SD card and then mount the filesystems from that on your laptop? (It hot-plugs fine on Linux Mint.) There's the extra step of dd'ing the card back into an image file, but it's not a hardship.

[pluggy]

You could DD the file to a USB memory stick or even a hard drive if you don't have the technology to do an SD card

[pksato]

Hi
After few attempts, I could mount two of partition os raspbian image.
Problem is how to determine offset byte of partitions begins?
Fdisk can show some information, file command also.

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$ /sbin/fdisk -lu 2012-12-16-wheezy-raspbian.img 
Disk 2012-12-16-wheezy-raspbian.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders, total 0 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
Disk identifier: 0x00017b69

                         Device Boot      Start         End      Blocks   Id  System
2012-12-16-wheezy-raspbian.img1            8192      122879       57344    c  W95 FAT32 (LBA)
2012-12-16-wheezy-raspbian.img2          122880     3788799     1832960   83  Linux

From above fdisk information, first partition start on sector 8182, and second on 122880. And each have 512 bytes.

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$ file 2012-12-16-wheezy-raspbian.img 
2012-12-16-wheezy-raspbian.img: x86 boot sector; partition 1: ID=0xc, starthead 130, startsector 8192, 114688 sectors; partition 2: ID=0x83, starthead 165, startsector 122880, 3665920 sectors, code offset 0xb8

File command show same information.

To get offset in bytes, multiply start sector by 512.
First partition have a offset of 4194304 bytes,
And, second, 62914560 bytes.

To mount,

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mkdir /mnt/img1
mount -t vfat -o loop,offset=4194304 /tmp/rpi/2012-12-16-wheezy-raspbian.img /mnt/img1/
mkdir /mnt/img2
mount -t ext4 -o loop,offset=62914560 /tmp/rpi/2012-12-16-wheezy-raspbian.img /mnt/img2/

Make modifications, umount and dump to SD card.

[Max]

For people that are too lazy to do offset calculations (like me):

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$ sudo kpartx -av your-image.img 
add map loop0p1 (252:5): 0 117187 linear /dev/loop0 1
add map loop0p2 (252:6): 0 3493888 linear /dev/loop0 118784
$ sudo mount /dev/mapper/loop0p2 /mnt

"sudo umount /mnt" and "sudo kpartx -d your-image.img" when done.

[Joe Schmoe]

kpartx looks interesting. It is not part of the default instal, though.

FWIW (addressing the main thread topic), I think that for most practical purposes, the sequence:

1) Write image to card (using a Linux system other than the Pi)
2) Make changes on the card (using a Linux system other than the Pi)
3) Boot card (on the Pi)

is going to be easiest and best.

You would only need to modify the image itself if you are planning on writing it to multiple cards.

[andrew R]

@redhawk, the problem with that is that you would need to know the offset to the second partition. Theoretically that is not impossible, but I don't know how to do it.

I think the problem you are seeing is that the image includes the partition table and two partitions, whereas the filesystem drivers expect to see single partitions.

Why can you not write the SD card and then mount the filesystems from that on your laptop? (It hot-plugs fine on Linux Mint.) There's the extra step of dd'ing the card back into an image file, but it's not a hardship.

"Why can you not write the SD card and then mount the filesystems from that on your laptop?"

looks like i was over-analyzing everything and the above suggestion did the trick...

burning the image to an sd card and sliding it right back into the laptop makes all partitions visible and editable. dont know why that didnt work when i first tried it.

i am still glad i posted this question-i have received some amazing mount syntaxes that i didnt even know existed....

thanks to all....

andrew.

[sonnym]

I combined the information in this thread into the following script:

Code: Select all

IMG_FILE=$(find dist/build/raspbian -name '*.img')
SECTOR_OFFSET=$(sudo /sbin/fdisk -l $IMG_FILE | awk '$6 == "Linux" { print $2 }')
BYTE_OFFSET=$(expr 512 \* $SECTOR_OFFSET)

sudo mount -o loop,offset=$BYTE_OFFSET $IMG_FILE dist/build/mnt

[sonnym]

A better method than manually calculating the offsets for the image file is to map the img partitions as devices. This can be done with the following (run as root):

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/sbin/modprobe loop
/sbin/kpartx -asv 2014-01-07-wheezy-raspbian.img
mount /dev/mapper/loop0p1 /mnt/rpi

You need to load the loop module before mapping devices. kpartx will tell you the name of the device (it may not be loop0), ala:

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add map loop0p1 (253:1): 0 196608 linear /dev/loop0 2048
add map loop0p2 (253:2): 0 849920 linear /dev/loop0 198656

[richardash1981]

A bit late to this, but you don't need kpartx in order to get the image file partitions accessible via a loopback - you can just use the -P option to losetup. A little more work, but only needs the util-linux package installed, which you almost certainly have.
First, we need a free loopback device to use:

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sudo losetup -f
/dev/loop0

then set it up with the file

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sudo losetup -P /dev/loop0 lighting-pi-20140328.img

fdisk can then show you the partitions on your image

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sudo fdisk -l /dev/loop0

and you can mount whichever partition you want

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sudo mount /dev/loop0p2 /media/spare/

When you are done, you unmount the file system, then detach the file from the loopback device

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sudo umount /media/spare/
sudo losetup -d /dev/loop0

[tvjon]

What version are you using?

losetup: invalid option -- 'P'

[richardash1981]

losetup from util-linux 2.22.2 (Gentoo)

The man page is dated July 2003, so this isn't exactly the bleeding edge.

[infogulch]

To expand on sonnym's script, this script mounts the image file passed as an argument to /mnt/FILENAME:

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#!/bin/sh

IMG_FILE=$1
SECTOR_OFFSET=$(sudo /sbin/fdisk -l $IMG_FILE | awk '$6 == "Linux" { print $2 }')
BYTE_OFFSET=$(expr 512 \* $SECTOR_OFFSET)

IMG_DIR=$(basename "$IMG_FILE")
IMG_DIR="${IMG_DIR%.*}"

echo Mounting at /mnt/$IMG_DIR

sudo mkdir -p /mnt/$IMG_DIR
sudo mount -o loop,offset=$BYTE_OFFSET $IMG_FILE /mnt/$IMG_DIR

Put this in my home dir named mount-image.sh, it works for me:

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infogulch@vm-xubuntu:~$ chmod 755 mount-image.sh 
infogulch@vm-xubuntu:~$ ./mount-image.sh 2013-09-10-wheezy-raspbian.img 
[sudo] password for infogulch: 
Mounting at /mnt/2013-09-10-wheezy-raspbian
infogulch@vm-xubuntu:~$ ls /mnt/2013-09-10-wheezy-raspbian/
bin   dev  home  lost+found  mnt  proc  run   selinux  sys  usr
boot  etc  lib   media       opt  root  sbin  srv      tmp  var
infogulch@vm-xubuntu:~$

[dpenezic]

Hi all,
in last post script need to use fdisk -lu instead fdisk -l .

I create script for mount and umount /boot and / from disk image. Code is follow:

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#!/bin/sh                                          
# Author: Dubravko Penezic, dpenezic@gmail.com     
#                                                  
# Credit to valuable answer from few users on Raspberry Pi Forum , http://www.raspberrypi.org/forums/viewtopic.php?f=63&t=28860
#

OPTION=$1
IMG_FILE=$2
MOUNT_POINT=/datacopy/RPI-raspbian-image/Work/Img

IMG_DIR=$(basename "$IMG_FILE")
IMG_DIR="${IMG_DIR%.*}"

if [[ "$#" -lt 2 || ("$1" != "m" && "$1" != "u") ]]
  then
    echo "Please use script as follow:"
    echo ""
    echo '> $0 m|u <disk_img_file>'
    echo "     m - mount"
    echo "     u - umount"
    exit 1
fi

if [[ "$1" == "m" ]]
  then
    SECTOR_OFFSET=$(sudo /sbin/fdisk -lu $IMG_FILE | awk '$6 == "Linux" { print $2 }')
    BYTE_OFFSET=$(expr 512 \* $SECTOR_OFFSET)
    SECTOR_OFFSET_BOOT=$(sudo /sbin/fdisk -lu $IMG_FILE | awk '$6 == "W95" { print $2 }')
    BYTE_OFFSET_BOOT=$(expr 512 \* $SECTOR_OFFSET_BOOT)

    echo Mounting image / at $MOUNT_POINT/$IMG_DIR
    echo Sector offset $SECTOR_OFFSET - Byte offset $BYTE_OFFSET

    sudo mkdir -p $MOUNT_POINT/$IMG_DIR
    sudo mount -t ext4 -o loop,offset=$BYTE_OFFSET $IMG_FILE $MOUNT_POINT/$IMG_DIR

    echo Sector offset $SECTOR_OFFSET_BOOT - Byte offset $BYTE_OFFSET_BOOT
    echo Mounting image /boot at $MOUNT_POINT/${IMG_DIR}_boot

    sudo mkdir -p $MOUNT_POINT/${IMG_DIR}_boot
    sudo mount -t vfat -o loop,offset=$BYTE_OFFSET_BOOT $IMG_FILE $MOUNT_POINT/${IMG_DIR}_boot
fi

if [[ "$1" == "u" ]]
  then

    echo Unmounting image / at $MOUNT_POINT/$IMG_DIR
    sudo umount $MOUNT_POINT/$IMG_DIR
    sudo rmdir $MOUNT_POINT/$IMG_DIR

    echo Unmounting image /boot at $MOUNT_POINT/${IMG_DIR}_boot
    sudo umount $MOUNT_POINT/${IMG_DIR}_boot
    sudo rmdir $MOUNT_POINT/${IMG_DIR}_boot

fi

[rumjar86]

sorry if the is an old thread, but I am having a similar issue. to start off I am trying to get a bitcoin miner running but the img file I have is for a model B and I have a B+ and the img file has files I need to get it to run correctly. I can't do the usb or card reader as with the img in question doesn't enable the usb and or lan so I'm stuck something bad.
I am still waiting for support on the bitcoin forums atm but info on this thing is rare as and so hoping I can just extract the files needed to the newer weezy and away i go or ssh into the new weezy to copy the files over into the right directories etc.
please any ideas would be greatly appreciated.
Josh

[pjf02536]

I found this very useful, and decided to make another useful addition to the script.

I added the ability to do an fsck to the primary partition, as I had several images that became corrupted (well not clean) because of various shutdown and power fail issues ... it happens. So I added an "f" option to fsck the primary and allwo you to correct issues and mske it clean...

Code: Select all

#!/bin/sh                                          
# Author: Dubravko Penezic, dpenezic@gmail.com
#           initial script mount and unmount

#  Updates: Pete Flahery, cometcoaster@gmail.com
#            added fsck capability "f" option
#            changed to run from current directory (the one that image is in)
#            NOTE: this can be run against a symlinked image file(s)

# Credit to valuable answer from few users on Raspberry Pi Forum , http://www.raspberrypi.org/forums/viewtopic.php?f=63&t=28860
#

OPTION=$1
IMG_FILE=$2

CWD=`pwd`
MOUNT_POINT=$CWD/img

IMG_DIR=$(basename "$IMG_FILE")
IMG_DIR="${IMG_DIR%.*}"

if [[ ( "$#" -lt 2 ) || ( "$1" != "m" && "$1" != "u" && "$1" != "f"  ) ]]
  then
    echo "Please use script as follow:"
    echo ""
    echo '> $0 m|u <disk_img_file>'
    echo "     m - mount"
    echo "     u - umount"
    echo "     f - fdisk it"
    exit 1
fi

if [[ ("$1" == "m" || "$1" == "f") ]]
  then
    SECTOR_OFFSET=$(sudo /sbin/fdisk -lu $IMG_FILE | awk '$6 == "Linux" { print $2 }')
    BYTE_OFFSET=$(expr 512 \* $SECTOR_OFFSET)
    SECTOR_OFFSET_BOOT=$(sudo /sbin/fdisk -lu $IMG_FILE | awk '$6 == "W95" { print $2 }')
    BYTE_OFFSET_BOOT=$(expr 512 \* $SECTOR_OFFSET_BOOT)

    echo Mounting image / at $MOUNT_POINT/$IMG_DIR
    echo Sector offset $SECTOR_OFFSET - Byte offset $BYTE_OFFSET

    if [[ "$1" == "m" ]];then
        sudo mkdir -p $MOUNT_POINT/$IMG_DIR
        sudo mount -t ext4 -o loop,offset=$BYTE_OFFSET $IMG_FILE $MOUNT_POINT/$IMG_DIR

        echo Sector offset $SECTOR_OFFSET_BOOT - Byte offset $BYTE_OFFSET_BOOT
        echo Mounting image /boot at $MOUNT_POINT/${IMG_DIR}_boot

        sudo mkdir -p $MOUNT_POINT/${IMG_DIR}_boot
        sudo mount -t vfat -o loop,offset=$BYTE_OFFSET_BOOT $IMG_FILE $MOUNT_POINT/${IMG_DIR}_boot
    else

        sudo losetup -o $BYTE_OFFSET /dev/loop999 $IMG_FILE
        sudo fsck -t ext4 /dev/loop999
        sudo losetup -d /dev/loop999
    fi
    
fi

if [[ "$1" == "u" ]]
  then

    echo Unmounting image / at $MOUNT_POINT/$IMG_DIR
    sudo umount $MOUNT_POINT/$IMG_DIR
    sudo rmdir $MOUNT_POINT/$IMG_DIR

    echo Unmounting image /boot at $MOUNT_POINT/${IMG_DIR}_boot
    sudo umount $MOUNT_POINT/${IMG_DIR}_boot
    sudo rmdir $MOUNT_POINT/${IMG_DIR}_boot

fi

[mahjongg]

all good and well, but the original post is eight years old, and the last post of this thread was five years old. Normally almost noting about your assumptions should still work, please don't do things like this, it only causing confusion, normally post like yours are simply deleted!

als threads older than a couple of years should be locked and marked obsolete, as they are several versions old, even before the introduction of system-D which brought radical changes.

also I see no reason at all top open and edit an image.

[dickon]

I do, but scripts like that make me cringe. losetup -P makes much, much more sense.

[mahjongg]

Ever heard of the expression "if you only have a hammer all problems look like a nail".

remember this was eight years ago, eight years less experience with linux.

[dickon]

losetup has had -P for as long as I can remember.