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49

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 ...


14

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

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

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

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

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

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 ...


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 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

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

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

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

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

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.


2

You need the kernel module to add support for NFS and/or CIFS. The "no such device" is a message you will get when the kernel module for the file system type does not exist. One way to check if the module is loaded is to do a lsmod | grep nfs. if it doesn't return any matches, then you do not have an nfs module loaded. There are kernel modules out there ...


2

Close Odin, disconnect your phone, restart Odin, reboot your phone, put the phone into Download mode again, and then connect your phone and ensure Odin sees it. Sometimes Odin just doesn't recognize the device and you need to try again. Odin will show something like the yellow highlighted area below when the phone is properly connected:


2

No, you do not have to reload or delete anything. However do make sure you take a NANDROID backup before you install one of those kernels. You can potentially get into a reboot-loop that can only be broken by flashing another (lower mhz) kernel or restoring to a previous NANDROID backup. I went from stock kernel to now running the ultra low voltage ...


2

The Odin-able kernels for my Galaxy S are simply the zImage in a .tar file. But the zImage has a peculiar format, and I believe it's specific to Samsung devices. I would assume that either the kernel you've compiled is the wrong format, or simply doesn't work and the system is restoring the stock kernel from the recovery image.


2

What does the developer say? Seriously every single rom that I've ever seen contained detailed instructions and more often than not a faq of some sorts for this reason exactly. Anyway, if the zip file contains a boot.img file than it's safe to assume that it will be flashed. The updater-script that handles the copying of files is generated automatically ...


2

Generally, what you need to achieve this is to connect to the serial console of the system. Like on a desktop system, this gives you all the kernel and init messages as the device boots, and access to a shell once the device has booted. How to connect to the serial console varies between devices, and you haven't told us which device you have. Usually, you ...


2

No. Android's not like a desktop GNU/Linux distro, where you can press I to get an interactive boot, or skip X and just boot to a shell. The only way to achieve this would be to build your own custom ROM after editing the init scripts (which have much the same function as on a desktop GNU/Linux system) to tailor the boot process how you like.


2

This link contains the parts where you can intervene / add your own functionality The rough flow is Power On > Bootloader > Kernel > Init Process > System Server > Boot Complete At the bootloader stage, the following is run: A. The first boot loader stage will detect and set up external RAM. B. Once external RAM is available and the system is ready the ...



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