Fastboot Fast Boot of Init-Boot

Fastboot mode is one of the most powerful tools for flashing files on an Android device. Here, in this article, we will explain how to flash boot and initboot files using Fastboot. For troubleshooting, rooting, or customizing an Android device, one needs to know how this is done. We will walk you through every step in great detail with tips to ensure smooth processing.

What is Fastboot?

Fastboot: a protocol/command-line utility that allows communication with an Android device while it is in Fastboot mode. Part of the bootloader interface, and allows access to a number of low-level modifications including flashing of partitions (boot, system, recovery), unlock or relock bootloader, clearing data and cache and access to other advanced debugging features.

Key Terms: boot and initboot

**What is the Boot Partition?

The boot partition contains the kernel and the ramdisk, which plays a major role in booting up the Android OS. This partition is thus very commonly modified or overwritten when custom ROMs or kernels are flashed.

What is the Initboot Partition?

The initboot partition is more of a recent development in newer devices running on Android. This is considered the entry point for system initialization and allows compatibility with Android Verified Boot (AVB) and dynamic partitions.

Preparation Before Flashing

Before proceeding to flashing commands, the following should be in place:

1. Bootloader Unlocking

Flashing requires an unlocked bootloader. For unlocking the bootloader:

1. Power your device on into Fastboot mode.
   • Press Volume Down + Power for most devices.
2. Connect it to your computer using a USB cable.
3. Issue the following command:

fastboot oem unlock

or
```bash
fastboot flashing unlock

Note: Unlocking the bootloader will wipe your device completely. You are advised to back up your data first.

2. Installing ADB and Fastboot Tools

First make sure that ADB and Fastboot tools are installed in your computer. You can download these from the Android Developers website.

3. Download Boot and Initboot Files

• Correctly download your device’s version of boot.img and initboot.img.
• Ensure that both files are applicable to your model of your device and current firmware.

How to Flash boot.img Using Fastboot

The procedure to flash a boot partition is pretty simple. Follow these steps meticulously:

1. Boot your device into Fastboot mode.

• Power off your device, and then hold Volume Down + Power until the Fastboot screen appears.

2. Connect your device to your PC using a USB cable.
3. Open a terminal or command prompt on your PC.
4. Change into the directory where your boot.img file is located.
5. Flash the boot image using the following command:

   fastboot flash boot boot.img
   

6. When the flashing process is complete, immediately reboot your device:

   fastboot reboot
   

How to Flash initboot.img Using Fastboot

For devices that use the initboot partition, flashing works in the following way:

1. Start your device in Fastboot mode and then attach it to your PC.
2. Open a terminal or command prompt and go to the directory holding your initboot.img file.
3. Use this command to flash the initboot image:

   fastboot flash init_boot initboot.img

4. Immediately reboot your device after the operation finishes:

   fastboot reboot
   

Common Issues and Troubleshooting

1. Device Not Recognised in Fastboot Mode

• USB debugging must be enabled on the device.
• Proper installation of USB drivers of the device to be used must be installed on the PC.
• Check the device using the command fastboot devices.

2. Flash Fails with “Partition Not Found” Error

• Double-check the name of the partition. Some other devices’ partition name might be different for example, instead of initboot, init_boot.
• See all partition names using this command: fastboot getvar all

3. Device is stuck in bootloop

• Re-flash correct boot or initboot image
• Wipe cache and data partitions:

fastboot erase cache
 fastboot erase userdata

Pros of Flashing boot and initboot

• Customisation: Enables installing custom ROMs, kernels, and other system modifications.
• Troubleshooting: Fixes corrupted boot partitions or software issues.
• Security: Restores the original boot or initboot image to ensure device integrity.

Safety Tips for Flashing

Always verify file integrity before flashing. Check for checksums to ensure files are not corrupted or damaged. Never interrupt the flashing process. Ensure that the battery condition of your device is up to the task-at least 50%. Never flash a file from an untrusted source, as this may damage your device.

Final Thoughts

Flashing of boot.img and initboot.img via Fastboot are very good ways to gain more control and personalize your Android device. Hopefully, this tutorial has shed some light on the process and better prepared you to undertake such tasks with confidence.

Frequently Asked Questions

1. Can I flash boot.img without unlocking the bootloader?

No, the bootloader must be unlocked to allow flashing custom images.

2. What if I flash an incompatible boot.img file?

Flashing an incompatible boot image will result in either a bootloop or an inoperable device. Always make sure that the file is compatible.

3. Do all devices require initboot flashing?

No, this step is required only for those devices which use the initboot partition. Check your device’s partition structure.

4. Can I relock the bootloader after flashing custom images?

Yes, but relocking bootloader may erase data and have incompatibility with custom ROMs or kernels.

5. How to restore original boot.img and initboot.img?

You can restore the original images by flashing the stock boot and initboot files provided by your device manufacturer.