46
It's a security concern. The Android documentation doesn't provide a lot of elaboration, stating simply:
The procedure must be confirmed on-screen, and deletes the user data for privacy reasons.
However, the privacy concern is relatively straightforward to extrapolate. Once the bootloader is unlocked, the device can be flashed with unsigned images. This ...
44
Found the solution!
You have to edit menu.lst file. Here is how:
boot in debug mode (usually the second option in boot menu)
when booting stops (for me it just hangs there with flashing cursor and without any prompt) enter mount -o remount,rw /mnt
enter cd /mnt/grub
enter vi menu.lst
press Shift+a
right under the first boot entry find the line starting ...
21
Please clarify what is the intended goal and why?
Android phones have their own boot-loaders and cannot be overridden by other means.
It is not like a PC's BIOS where you can switch the ordering of boot to boot from certain devices such as Network PXE, USB, Primary/Secondary H.D.D...
Edit:
After the comments below, and in relation to the OP's question
...
21
To make the system recognize the Android device, in their several modes, one needs to set permissions for his user in udev.
You need to repeat this process of loading Android udev IDs, for every mode the phone has (operating system, bootloader or recovery) because they have different USB IDs
# reboot into fastboot mode
adb reboot bootloader
# grab you ...
17
The term "brick" usually refers to the stone, which means: "device can only be used as paper-weight". Taken literally, there's no way to "unbrick".
However, you also find terms like "hard-brick" and "soft-brick" used, which makes the term "brick" less absolute: A soft-brick is something you easily can recover from (count it as a "temporary paper-weight"), ...
17
Personally I had to run fastboot as root/sudo for fastboot to detect the device. I tried this on Linux as I don't own a Mac, but it's *NIX anyway ;)
14
CyanogenMod - in a vanilla or official build - will not typically contain a bootloader. On many devices there is really no good way to even overwrite the bootloader because it is on protected memory (the bootloader is "locked") and cannot be overwritten. It installs a boot image and a system image (i.e. writes to the /boot and /system partitions). I've heard ...
14
There's a couple of ways to do this:
cat /proc/last_kmsg > /sdcard/last_kernel_message_log.txt
dmesg > /sdcard/kernel_boot_log.txt
plug in the usb cable with the smart-phone switched off. Then issue the command adb logcat from your Windows cmd or Linux terminal, it will hang waiting for the device to come on-line, now power up the smart-phone. The ...
13
The Application Bootloader ABOOT boots the Android kernel/Recovery kernel.
It is the mechanism to download images onto the device from a host machine (like Windows/Linux PC).
On Samsung devices it runs the ODIN protocol on the device.
The Primary Bootloader boot part is a computer program that loads the main operating system or runtime environment for ...
13
The instructions don't make mention of the setting in the device's developer options.
Make sure to enable the "OEM unlocking" setting there:
12
The boot-loader code is stored within the /boot partition. Majority of Android handsets uses the Qualcomm's Boot Loader, called LK (Little Kernel), barring Samsung, which uses their own form of boot-code.
LK has the following:
Variety of nand devices for bootup
USB driver to enable upgrading images over usb during development
Keypad driver to enable ...
12
For future reference, this was my related case (involving a Nexus 4):
I tried to bring my phone back to the original state (bootloader locked + stock rom).
Now fastboot devices did not show the device where adb device did, until I put the phone in fastboot mode (this makes sense, but took me a while to figure out...)
To put the Nexus 4 in fastboot mode:
...
10
That screen means your device is in "download" mode, which allows it to be reflashed using Samsung's Odin utility (or the open source alternative Heimdall). It's accessed by holding the volume down button when powering on your Galaxy Nexus.
Also, to clear up some confusion, this is not Fastboot mode - that is different. You access fastboot mode by holding ...
9
Brick is a much-hyped word that gets bandied about without understanding what it is.
There's two types of brick, hard and soft. Let's go through this to make the distinction clearer.
Hard - this is where the handset will absolutely refuse to boot at the press of the power button.
Diagnostics: Dead screen, no power. That is the symptom of a hard brick.
...
8
Charging control is done via hardware to prevent ruining the battery in case of software errors. That is why (most?) devices charge even when powered off. The status display that is then shown is just a "minimal OS" that queries the current status from the battery charger hardware.
8
Boot process of embedded system is similar to PC from overview level, but slightly different from microscopic level.
Here's the boot process of an Android device:
PC-BIOS/BootMonitor, MBR and GRUB/LILO etc are all combined in one Boot Strap Firmware called Bootloader. Its init.S initializes stacks, zeros the BSS segment and calls _main() in main.c. The ...
8
Yes. Locking the bootloader is possible after you have installed a custom firmware.
A locked bootloader will not allow you to ad-hoc boot custom binaries (using fastboot boot boot.img and will not allow you to directly write to the flash chips. An unlocked bootloader however does offer you this and newly available commands are:
fastboot flash partition ...
8
If you have been waiting an excessive amount of time for your phone to boot (eg. leaving it overnight to boot) but it is still at the boot animation, you may be in bootloop. This is when the phone fails to boot due to some errors in the /system partition. As a preliminary measurement, you should perform a factory reset (or wipe /data) to see if that helps. ...
7
I had the same problem with InFocus M512, recognized by adb but not by fastboot when in download mode.
I've found that specifying vendor ID with -i works (0xID). fastboot -i 0x0489 worked for me.
7
Posting this not so much for the asker, since it was asked ten hours ago, but for others who find this question:
Lollipop's first boot can take a long time. On my Nexus 4, after the OTA update from 4.4.4, it took about half an hour. At least 10 minutes of this was spent in the "flying colours" boot screen. I'd make sure it has power, and leave it for at ...
7
Just reboot the device; at this point there's no harm that can be done since the data was being wiped anyways.
6
If you have a locked bootloader, it's S-ON. If you fully unlock the bootloader it's S-OFF. As eldarerathis notes below there's an intermediate state, where it's unlocked but still S-ON, where you can flash recoveries and ROMs but not radio firmware and so on.
If you don't unlock the bootloader, you can't flash unsigned firmware and most often can't alter ...
6
Full instructions can be found here.
In short:
Install SDK
Get the Fastboot.exe and place in your SDK/tools
Turn on USB debugging on phone
Connect to PC via USB
Using adb, run adb reboot bootloader
At the bootloader, run fastboot oem unlock
Accept dialog to unlock bootloader
Start phone, phone will reboot, do not battery pull!
Afterwards, you can get root ...
6
HBOOT is bootloader. It lives inside NAND's first partition, mtd0 (if partition map is MTD). It is loaded in memory (RAM) when device is switched ON. Its jobs are:
Check the Hardware.
Initialize the Hardware.
Start the Operating System (Either Android or Recovery).
HBOOT can also support doing more than this like flashing ROMs.
Something More: Nandroid ...
6
There's a guide on Rooting Xperia S ICS and GB over at XDAs. Not having any XPeria device, I cannot verify -- but the comments on the thread confirm it working. It does not even require the bootloader to be unlocked.
Requirements for that method:
Windows
Net framework 3.5 or later
Preparation:
Application Settings: [Unknown sources] checked {Allowed}
...
6
It is possible in a sense, however. Given the limitations mentioned in @t0mm13b 's answer, it makes sense that the mentioned boot loader (lk) is incapable of doing this. So, we boot a custom kernel from fastboot (for testing), which boots, enables OTG functionality and once a valid kernel is found on the OTG device which is connected, chainloads that into ...
6
Encrypt your filesystem. You'll need to enter a password or PIN on every boot to decrypt it, so as soon as the device is rebooted none of your personal data will be readable. TWRP even supports encrypted filesystems (it prompts you for your password when it starts as well, I think). If your device is at least 4.2.2 then you can even leave ADB on; they'd need ...
6
The bootloader is not generally on the /boot partition, it's on a separate one, although that's not really the crux of the issue.
The problem occurs when the bootloader is cryptographically signed, which is intended to prevent you from replacing it with your own. The device will check the signature of the bootloader at startup and refuse to boot one with an ...
6
Assuming your device adheres to some Android standards, you'd want to run fastboot oem device-info.
Often you can also run fastboot reboot-bootloader to get into the bootloader which often says right there on screen whether it's locked or not.
Different devices can display the lock state differently.
fastboot is located in %ANDROID_SDK_DIR%\platform-tools,...
6
Bootloader
The low level implementation of a system which can be used to flash software onto your phone's partitions. Often used to flash root privileges or Stock Roms.
Recovery
The recovery is another system used to manage/wipe/reformat your partitions. TWRP refers to a custom Recovery which allows you to install custom roms in a zip format. The ...
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