BULBIboot

BULBIboot is an aarch64 bootloader for Linux. It is designed to be simple and easy to use.

Also, BULBIboot is better than pikaboot.

Usable features

• Boot Linux kernel at EL1, EL2 & EL3
• Download a kernel for emrgency booting via serial
• Dump some memory regions and print them to console
• Test the memory efficiency (memtest)

Hidden but useful features

• Secure "preboot system"
• Bootloader signature verification
• Bootloader encryption
• -O3 optimization level
• CRC32 verification of the kernel during boot and ermgency boot download

How to build & boot

Install the dependencies

First, you need to install the dependencies. You can do it with the following command:

make dependencies

Note that this routine is compatible with apt, pacman and dnf package managers.

Build the images

To build the images (encrypted and clear), just run the following command:

make images

Running make also do the same trick.

Booting with QEMU

To boot the bootloader with QEMU, just run the following command:

make boot

If you want to boot the bootloader with QEMU with a GDB-stub listener, just run make boot_gdb

If you are using VSCode, you can use the .vscode/launch.json file to debug the bootloader with GDB.

Then, when QEMU is running, you will notice a path to something like /dev/pts/<n> (where <n> is a number). This is the path to the serial port. You can use it to connect to the bootloader.

If you want to use the serial port with screen, you can use the following command:

screen /dev/pts/<n>

How to use

See the HOWTO.md for more details.

Work in progress

Here is a list of some features that I worked on, but I didn't finish:

• Kernel signature verification

  • I worked on it, but I didn't finish it, because it need a position-independent code (PIC) compilation to work.

• Multiple boards support

  • I worked on it, but I didn't finish it, because I worked on an Orange Pi and Vexpress board, which are aarch32 boards.

License

BULBIboot is licensed under the Beerware license. See the LICENSE file for more details.