Debian 10

Exploring .img Files on Linux and create your custom one

keopx — Thu, 26 Dec 2019 10:50:37 +0000

Exploring .img Files on Linux and create your custom one

Discover the hidden secrets of a monolithic .img file
Mount the partitions in an .img file using losetup, kpartx and mount
Create your own .img files and use them as virtual disks
Write out your virtual disk image to a thumb drive (or any drive for that matter) for use later

Install packages

$ sudo aptitude install kpartx xz-utils

Decompress image

Once its downloaded you will want to uncompress it with xz --decompress:

$ xz --decompress Retrobro128KillerHomeConsole.img.img.xz

Mount image

We’re going to attach the image file to what is known as a loopback device.

$ sudo losetup /dev/loop0 Retrobro128KillerHomeConsole.img

Note: We used /dev/loop0 in this example. If /dev/loop0 wasn’t available to us (that is, it was already in use), we could have chosen /dev/loop1, etc.

$ sudo losetup -a /dev/loop0: [65026]:28970069 (/home/keopx/Retrobro128KillerHomeConsole.img)

Now /dev/loop0 is attached. How about look at the partition table with fdisk?

$ sudo fdisk -l /dev/loop0 Disco /dev/loop0: 119,8 GiB, 128579534848 bytes, 251131904 sectores Unidades: sectores de 1 * 512 = 512 bytes Tamaño de sector (lógico/físico): 512 bytes / 512 bytes Tamaño de E/S (mínimo/óptimo): 512 bytes / 512 bytes Tipo de etiqueta de disco: dos Identificador del disco: 0xf2d3cb4f Disposit. Inicio Comienzo Final Sectores Tamaño Id Tipo /dev/loop0p1 * 8192 124927 116736 57M e W95 FAT16 (LBA) /dev/loop0p2 124928 251131903 251006976 119,7G 83 Linux

To see what kpartx would map, run it with the -l option:

$ sudo kpartx -l /dev/loop0 loop0p1 : 0 116736 /dev/loop0 8192 loop0p2 : 0 251006976 /dev/loop0 124928

Let’s go ahead and run it and add the maps:

$ sudo kpartx -a /dev/loop0

Now you can see new devices on dolphin.

Running a shell:

Now that the partitions are mapped, let’s examine the filesystems on each partition with file and the --special-files and --dereference options.

$ sudo file -sL /dev/mapper/loop0p1 /dev/mapper/loop0p1: DOS/MBR boot sector, code offset 0x3c+2, OEM-ID "mkfs.fat", sectors/cluster 4, reserved sectors 4, root entries 512, Media descriptor 0xf8, sectors/FAT 116, sectors/track 32, heads 64, sectors 116736 (volumes > 32 MB), serial number 0xb13de1e5, label: "boot ", FAT (16 bit)

$ sudo file -sL /dev/mapper/loop0p2 /dev/mapper/loop0p2: Linux rev 1.0 ext4 filesystem data, UUID=c50e928e-5669-44d0-8e3c-a59d21ad3da2, volume name "retropie" (extents) (64bit) (large files)

Now that we have our partitions mapped, we can mount them. Create two directories to serve as mountpoints:

$ mkdir boot # We will mount the FAT partition here $ mkdir retropie # We will mount the ext4 partition here

Once they are created, mount the filesystems (only system in my case).

$ sudo mount /dev/mapper/loop0p2 retropie

Umount image

Once you are done and want to “let go” of the .img file, reverse the process with:

$ sudo umount retropie $ sudo kpartx -d /dev/loop0 $ sudo losetup -d /dev/loop0

Reference:

https://dev.iachieved.it/iachievedit/exploring-img-files-on-linux/

keopx Jue, 26/12/2019 - 11:50

Categoria

Debian 10

Raspberry pi

Tag

bash

Terminal

consola

Comentarios

Debian 10 Buster Killer 1535 wireless

keopx — Wed, 31 Jul 2019 09:49:36 +0000

Debian 10 Buster Killer 1535 wireless

Source list

vim /etc/apt/sources.list

deb http://deb.debian.org/debian buster main contrib non-free deb-src http://deb.debian.org/debian buster main contrib non-free deb http://deb.debian.org/debian-security/ buster/updates main contrib non-free deb-src http://deb.debian.org/debian-security/ buster/updates main contrib non-free deb http://deb.debian.org/debian buster-updates main contrib non-free deb-src http://deb.debian.org/debian buster-updates main contrib non-free deb http://deb.debian.org/debian buster-backports main contrib non-free deb-src http://deb.debian.org/debian buster-backports main contrib non-free