GSoC'24: Linux x86 Boot Protocol Support

The Linux boot protocol plays an important role in the initialization of the Linux operating system, emphasizing the importance of system optimization and scalability.

Project overview#

The Linux boot protocol plays an important role in the initialization of the Linux operating system, emphasizing the importance of system optimization and scalability. This system ensures a seamless transfer of control from the bootloader to the Linux kernel by providing essential information including memory map, command line parameters, and device specifications. By adhering to a uniform boot protocol, Linux achieves a level of versatility across the hardware spectrum of architectures and bootloader functions. Essentially, this protocol is a commitment to a standardized approach that is not only stable but also facilitates bootloader development, improving compatibility and reliability. In particular, the Linux boot protocol greatly contributes to the overall robustness and reliability of the bootstrapping process on Linux-based systems. Almost, if not all, widely available bootloaders that exist on the market are able to speak this protocol and Unikraft, being unable to be detected by these bootloaders as a Linux Boot Protocol compliant system, is hindering the ability to boot on a very large amount of platforms.

Current Progress#

I already compiled qemu 9.0.1 using the following flags: --enable-debug --extra-cflags="-g3" --extra-ldflags="-g3" --disable-strip --enable-kvm --enable-avx2 --enable-avx512bw --enable-avx512f to help me debug. At the moment, I am looking into creating support/scripts/mklinux_x86.py using as inspiration the already existing mklinux.py and the ARM64 PR. The mklinux_x86.py script mainly contains functions that help parse and set certain fields of the image header.

The header will look as follows:

For more details about certain fields, read here.

Next Steps#

Once everything works for QEMU, I will move onto GRUB2 and look into making lxboot x86 work with it as ISO and as Disk. Boot loaders have unique reserved identifiers, placed in the type_of_loader field. The type_of_loader field will contain 0xTV, where T is the loader's ID and V is its version. If a boot loader does not have a ID, use 0xFF.

Assigned boot loader ids (hexadecimal):

About Me#

I am Mihnea Firoiu, a second year Computer Science and Engineering student at University POLITEHNICA of Bucharest. My main interests are operating systems, low-level programming and cyber security.