What is a zImage file?

zImage: a compressed version of the Linux kernel image that is self-extracting. uImage: an image file that has a U-Boot wrapper (installed by the mkimage utility) that includes the OS type and loader information. A very common practice (e.g. the typical Linux kernel Makefile) is to use a zImage file.

Where is zImage?

The file called zImage is the compressed kernel image that lives in arch/i386/boot after you issued make zImage or make boot — the latter invocation is the one I prefer, as it works unchanged on other platforms.

What is a Rootfs image?

A rootfs image is just a file system image, that hosts at least an init system. Note that, whichever file system you choose to use, support for it will have to be compiled into the kernel, so it can be mounted at boot time.

How do I extract Vmlinuz?

Extracting the Linux kernel image (vmlinuz) You will be able to find the extract-linux script at /usr/src/linux-headers-$(uname -r)/scripts/extract-vmlinux . You will be able to find the extract-linux script at /usr/src/kernels/$(uname -r)/scripts/extract-vmlinux .

How do I extract device from boot IMG?


  1. Install unpackbootimg. Go to https://github.com/jsharma44/bootimg-tools and download as a zip or use git clone command. extract files. cd directory.
  2. copy unpackbootimg and mkbootimg to /usr/bin. sudo cp unpackbootimg /usr/bin. sudo cp mkbootimg /usr/bin.
  3. Extracting boot.img from your device.

What is a key difference between a zImage and bzImage kernel image?

26 kernel (starts at line 44): Code: Note: the difference between ‘zImage’ files and ‘bzImage’ files is that ‘bzImage’ uses a different layout and a different loading algorithm, and thus has a larger capacity. Both files use gzip compression.

What is Rootfs?

The root file system (named rootfs in our sample error message) is the most basic component of Linux. A root file system contains everything needed to support a full Linux system. It contains all the applications, configurations, devices, data, and more. Without the root file system, your Linux system cannot run.

What does vmlinuz stand for?

vmlinuz = Virtual Memory LINUx gZip = Compressed Linux kernel Executable vmlinux = Virtual Memory LINUX = Non-compressed Linux Kernel Executable At the head of this kernel image (vmlinuz) is a routine that does some minimal amount of hardware setup and then decompresses the kernel contained within the kernel image and …

How do I open a boot image?

How to unpack and edit Android boot img?

  1. Tools selection.
  2. Tools installation.
  3. Fetch the boot.img file.
  4. Unpack the original boot.img file.
  5. Rebuild to get the new new-boot.img file.
  6. Flash the new-boot.img file onto the device.
  7. Conclusion.

Can you use a zImage inside a uimage?

Actually it’s pretty stupid to use a zImage inside an uImage. It is much better to use normal (uncompressed) kernel image, compress it using just gzip, and use this as poayload for mkimage. This way U-Boot does the uncompresiong instead of including yet another uncompressor with each kernel image.

What is the difference between zImage and rootfs?

You can replace it with your own code if you would like MPU to run bare-metal code without OS (like microcontroller). zImage is compressed version of the Linux kernel image that is self-extracting. rootfs is root file system, which contains all applications, libs and in most cases everything, including home folder.

What’s the difference between a kernel and a zImage?

In addition to the kernel zImage may also contain the inital file system (initramfs, initrd) the kernel uses to ‘bring up the system’ before the rootfs is mounted. zImage is the actual binary image of the compiled kernel.

Why is the zImage file not compressed in Linux?

Since a zImage file is self-extracting (i.e. needs no external decompressors), the wrapper would indicate that this kernel is “not compressed” even though it actually is. Kernel boot process ..