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Is kernel mode of operating system and root permissions in android same thing?

Root permissions and kernel mode are not the same thing. Programs with root access can access part of the kernel, but root is not the kernel itself. The Android (and Linux) user model has a set of ...
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8 votes

What is the difference between the Linux Kernel and the Android Kernel?

I think this Android Source is a great documentation for understanding it. And here is a list of changes done from mainline kernel for android kernel 4.14. The largest features include: 19.8% ...
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8 votes
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Is it possible to flash a boot.img kernel with TWRP?

Boot into TWRP, select Install and follow the screenshots for the rest. (Click image to enlarge) It's not a problem for TWRP to which ROM your particular kernel belongs. The size should not be ...
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8 votes
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Why does Android differ so much from Linux?

Why didn't Google just take a Linux distribution ... and create a desktop environment for touchscreens? Because they didn't want to create a desktop environment for touchscreens: they wanted to ...
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8 votes
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Backup/dump kernel image (and full ROM) without root for Mediatek Devices

To answer my own question! Warning, in some very rare cases this doesn't work or could be dangerous. For example, Amazon Fire devices refuse to communicate with these tools despite being MediaTek. ...
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8 votes
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How can I enable last_kmsg?

Back in 2012, /proc/last_kmsg (1) used to be a dump of kernel console messages, exported after reboots by Android's ram_console functionality (CONFIG_ANDROID_RAM_CONSOLE), which used persistent_ram (...
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8 votes
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How to make Ethernet work on Android over OTG?

There is a long list of Ethernet related questions but none has a comprehensive answer covering all aspects. I'm generalizing your question in order to share my knowledge on this. This is what you ...
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7 votes
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How does CF-Autoroot work?

On Nexus devices, at least: CF Auto-Root works by unlocking the device's boot loader via fastboot (if it isn't already unlocked), then sending the device a custom boot image (kernel and ramdisk) that ...
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  • 1,412
7 votes

Backup/dump kernel image without root or twrp/cwm

It is possible to dump device partitions without root or custom recovery - if your device has "fastboot" mode and is boot unlocked. I'm not going to describe unlocking the boot loader, but with a ...
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  • 171
7 votes
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Booting kernel from fastboot

When you use fastboot boot FILE.img, the image is downloaded and written into the RAM and than the normal procedure to boot a boot.img is followed. No changes to any partition takes place. If the ...
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6 votes
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What happens if you install another phone's kernel on yours?

At a simple level, the effects would be catastrophic. The system wouldn't boot, and you would probably hard-brick OR super-brick. Kernels are the direct system for managing communication between ...
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6 votes
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Is it possible to extract the kernel and device tree from a rom?

If it was that easy then we'd have custom ROMs in no time for every phone on the planet. What's on our phone are compiled, it's basically impossible to decompile them (modern decompilers are not as ...
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5 votes
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What does it mean by letter 'g' in a kernel version string such as 3.4.0-gd59db4e?

It stands for git, the name of the version control system used for the Linux kernel. Git itself isn't an abbreviation, it's just the name of the system. The git describe command is what's used to ...
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5 votes
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Building ROMs & Kernels?

1) Building in Android could mean: - building a deliverable in the android build tree - building a deliverable on an android platform having build tools installed - building the AOSP (Android ...
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5 votes
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Can IMEI number of a device really be changed

IMEI is an baseband identifier so it's stored on non-writable memory. There are two IMEIs actually - display and hardware. It's possible to change the display IMEI on rooted devices, but no way to ...
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5 votes
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CPU-Z shows 8 cores, but 4 of them are stopped

Is there any way of activating all cores? You can't. The hardware is not designed to have all 8 cores active. The reason for this is that this Octacore CPU is actually based on big.LITTLE technology,...
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5 votes

Where are kernel modules installed?

There are two ways Linux kernel modules are built: 1. as a part of kernel executable binary (compressed image) i.e. with CONFIG_*=y options at build time, or 2. as separate kernel object (.ko) files ...
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5 votes
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What is needed to run ELF binaries compiled from android APKs? (understanding android internals)

What is needed to run ELF binaries compiled from Android APKs? A simple hello world app which does nothing except printing Hello World! (no animations, no sounds, no menus), running on Android 9 ...
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4 votes
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Is it possible to unload built-in kernel module?

No. Built-in drivers aren't modules, they are built-in (hence the name). If it's not showing in lsmod, you can't get rid of it short of building a new kernel.
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4 votes

What is the difference between: Rooting, Jailbreaking, ROM, Mod, etc.?

TL;DR version: Unlocking the bootloader The initial program when you boot is the bootloader. If "locked" it may: 1) block attempts at flashing 2) refuse to boot the phone if something unauthorized ...
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Can system apps be enabled/disabled directly from the filesystem?

Whether an app is enabled or disabled is stored in a single file /data/system/users/0/package-restrictions.xml. I took the following steps to re-enable the Google App and solve my bootloop problem: ...
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4 votes
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Application Sandboxing in Android

Every single application that is installed on your phone, gets a UID. It is a number that Android uses to identify the apps so it can check from what app commands are executed and check the ...
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3 votes

What does "se.infra@SEP-138#1" mean on kernel version?

This is the name of the user and computer that was used to build the kernel. "se.infra" isn't a username belonging to a real person, but an account used by the build infrastructure at Samsung. It's ...
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3 votes
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How do I find the kernel config for my ROM?

If the kernel wasn't compiled with /proc/config.gz support turned on, then the only sure way is to look at the source tree that was used to compile the kernel you're running. Copy the config.h file ...
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3 votes
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Does CyanogenMod include a kernel?

Looking at the repository for that device, I can see that the specified kernel is built from source using the source found here and the cyanogenmod_i9305_defconfig configuration file. You can tell ...
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3 votes
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Where is the .config hidden on Samsung Galaxy S4?

/proc/config.gz (and consequently .config), a file containing all needed flags for the Linux kernel building process, can only be found if the kernel maker / your device manufacturer explicitly ...
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  • 954
3 votes

Help to understand working of powerbutton and volume rockers

The problem with understanding any physical buttons on an Android, is that they are extremely hardware dependent. Usually they're connected to some GPIO port on either the application processor (AP) ...
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3 votes

How can I find the name of the Kernel and its version that is running in my phone?

Unless Marshmallow has some unnecessary native changes, you should be able to see the kernel version in many Android releases from Settings → About phone. (Click image to enlarge) A command ...
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3 votes
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What does the ROM files (FACTORYFS, HIDDEN, CACHE, PARAM, etc.) mean?

From [INFO] What the ROM files mean boot.bin This is the Primitive Bootloader. Seems to make some basic initializations and finally loads the secondary bootloader. Sbl.bin The Secondary ...
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