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69

Rooting and Jailbreaking are essentially the same things, Jailbreaking is the iPhone users' word for what Android users call Rooting. Rooting is when you gain "Root" access to the phone giving you the power to do anything you want to it (it comes from the Unix Root User, essentially the Unix equivalent to the Windows Administrator account). Normally you're ...


50

Android shares very little with a typical Linux distribution. In fact, this is where Richard Stallman's "GNU/Linux" distinction comes in handy — Android isn't really a Unix-like general purpose operating system with a Linux kernel. It's a new system which happens to use the Linux kernel. This goes all the way down to its own custom libc implementation ...


20

Rooting and Jailbreaking refers to the same thing. The term Jailbreaking comes from Apple's iPhone community, the preferred term in Android is rooting. Rooting/Jailbreaking refers to enabling the administrator/superuser/root/user-id-0 user on the phone. In unrooted device, the superuser account is disabled for security purpose. The superuser possess full ...


15

Kernels vary from manufacturer to manufacturer. A lot of those kernels come from the pure stock kernel line of sources found on CAF, what these manufacturers do is take those stock sources, modify them to suit based on the board/chipset used, also, implement their own drivers. Take a good look around you, there's variations of touchscreens, variations of ...


14

The Linux user IDs that Android uses to isolate apps from each other are completely unrelated to user profiles on Android 4.2 tablets. In Android, each app gets its own directory for saving data. The Linux user ID system is used to make sure apps can't read each others' data. But all these data directories are inside one directory on the filesystem, ...


7

Use adb to push them to /system/lib/modules, then reboot. Android should load them at boot as long as they're in that directory, I believe. shell> adb push module.ko /system/lib/modules/ shell> adb reboot If you get a "read-only filesystem" error then remount /system as read/write first, then push them. Usually you can do this with adb remount. You ...


7

Yes you're correct. Android will use CPU frequency as required including deep sleep to highest CPU frequency. If Android uses 1.2Ghz for high end task it will consume more battery but on the other hand will finish the task quicker than 1Ghz. Many custom ROM also allows you to change this CPU scaling behavior by changing the governor. For eg: if you choose ...


7

Yes, it is possible to install custom kernels on stock roms. The kernel developer will usually say which roms (or types of roms) the kernel supports. If you are not sure you can try reading the kernel thread, and there will always be poeple saying things like "working great on [firmware version here]". This way you can also make sure that it will work ok on ...


7

There are perfectly good reasons why those informations are readable, and that's nothing dangerous (writing, however, would be). This is inherited from the Linux system Android builds upon -- and I will give you a few short examples to show you the good of it: If you list contents of the /proc (virtual) directory, you will find things like e.g.: ...


7

The filesystem support is device-specific, and in fact many devices using Android 2.3 support ext3 in the kernel (or ext4, which can also mount ext3 and ext2 filesystems). Usually the difference in filesystem support is due to different hardware. Older devices often used raw NAND flash chips and MTD drivers in Linux, which did not support conventional ...


6

I'm actually not sure that the kernel version matters for this exploit. It was a bug that was patched in the platform_system_core repository, which I think comprises libraries and system files that live on in the /system directory (the README says as much). The patch was committed on July 19, 2010 (in the Froyo branch, anyway). I'd wager that any kernel ...


5

No, The DroidX can not run custom kernels. "It is still impossible to flash custom kernels on the Droid X, but the ROM developer community has matured to a point where they’re able to make great things happen on this phone without having to rely on changes to the kernel."


5

Does flashing a new kernel require flashing a new ROM? It depends. You can't normally flash a 2.3 kernel over a 2.2 ROM, and so on. You can't flash a CyanogenMOD kernel on a stock ROM in most cases, and vice versa. But you should be able to flash any Android X.X stock-based kernel over any Android X.X stock-based ROM. For example, there are no issues ...


5

The PC architecture is built around commodity parts because it started out as clones of a specific product, the IBM PC, that were specifically designed to be compatible with it, and therefore with each other. Generally speaking, you could take a program or peripheral device from one PC-compatible and put it into another, and expect it to work. That ability ...


5

The kernel on your device is tied heavily to the version of the Android operating system you're running. Sony releases your phone with the "stock ROM" (think a "stock" car in stock car racing; no customization, just as-is from the factory), including the stock kernel. Normally, your kernel would be updated when the operating system - your "ROM" - is updated. ...


5

You can find all of the stock kernel versions at the Wikipedia Android version history page. It has the kernel version for each version of Android; it's at the end of the descriptions of each Android version. Table from Wikipedia: Android Version |API Level |Linux Kernel in AOSP ---------------------------------------------------- 1.5 Cupcake ...


4

CyanogenMod has a good definition of ROM (and a lot of the other terms on that list) Read Only Memory. In the context of an Android device, ROM is the internal flash memory where the core operating system resides. It can also refer to a specific version firmware that can be applied to a device through a process usually referred to as ...


4

The kernel is part of the "boot image", which is stored in a separate partition in the flash memory, not in a normal file. See http://android-dls.com/wiki/index.php?title=HOWTO:_Unpack,_Edit,_and_Re-Pack_Boot_Images


4

The files /proc/<pid>/maps /proc/<pid>/smaps are NOT universally readable by anyone, at least not in stock device. Try running from a Terminal Emulator from inside Android (running as a regular user), instead of ADB (which runs at a slightly elevated privilege). ADB runs with a lot of privileges because it's used for debugging and need to be ...


3

You can verify by checking /proc/config.gz and search through it looking for the configure option - CONFIG_BLK_DEV_LOOP=y. To do that you need to do it this way: cp /proc/config.gz /sdcard/kernel_config.gz and adb pull /sdcard/kernel_config.gz Unzip the kernel_config.gz and open it up in a notepad or text editor and search it. If its either # ...


3

Some phones' partitions have a separate partition for the kernel (often called "boot") that is separate from the one that holds /system. Unzip the CynanogenMod update.zip - there should be a boot.img inside. If you have fastboot and know how to use it, you can flash boot.img with ./fastboot flash boot /path/to/boot.img(You will need to be S-OFF for this; ...


3

CyanogenMod is a famous community-build Android ROM for multiple Android devices. Give you a very different user experience. CyanogenMod is a free, community built distribution of Android 2.2 which greatly extends the capabilities of your phone. Require flash : Yes Custom ROM: Yes (that's mean no Samsung stuffs, changed app launcher, etc) Custom ...


3

Firmware refers to the whole Android Software Stack: Kernel (incl. drivers), Dalvik VM, and the Operating System. However, it does not include applications installed from Market. Firmware can be official (released by the manufacturer and/or service provider) or it can be unofficial (released by modding community).


3

Well.... drivers and the kernel are not exactly the same. Drivers are what control the cell antenna, wifi, bluetooth, etc. These are proprietary drivers because the manufacturer has to create a way (the drivers) to talk to their hardware. The kernel is an intermediary level between the OS/application and the actual drivers (or cpu or memory or any other ...


3

The reason is because Android's Linux kernel are generally not compiled on Android itself, instead it had to be cross compiled from another computer. This causes various issues, because the device configuration are not available on compile time, and it is not feasible to compile a generic kernel with all drivers due to space limitation (whereas most desktop ...


3

The differences change from version to version (both of Linux and of Android), and the exact kernel is different for each device. A kernel for Android is a mainstream Linux kernel, with additional drivers for the specific device, and other additional functionality, such as enhanced power management or faster graphics support. Many features in the Android ...


3

Go to Settings -> About phone menu and scroll all the way to the bottom: Tap the "SELinux status" menu 3 times in a row in a quick succession. This will bring up a prompt asking you to confirm enabling the other modes: Be aware that currently this feature is still under heavy development, and isn't supported on all devices yet.


3

C source code is compiled into executable code. There's very little need for C source code files to exist on Android devices. If you want Linux kernel source you need to head over to Kernel.org.


3

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) or cellular processor (CP/modem), and on some devices (MTK,Qualcomm) these are combined in a SoC. In other devices, there is a separate touch screen MCU, that ...


3

/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 enabled config.gz availability when the Linux kernel was being built. So if it's not present in /proc, you'd have to either do a trial-and-error, get help from ...



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