vboot is a custom bootloader for the Veracyon Project. The purpose of the bootloader is to prepare and get the system into a known good configuration for vkernel, as well as determine chipset specific information that can then be provided to the kernel.
vboot currently assumes an i386 environment.
vboot will be a fully multiboot 1 compliant bootloader. It will load an ELF based kernel, any required modules/ramdisks and configure the system depending on what the kernel requires.
To begin with, there is a much stronger emphasis on getting it working for vkernel and the VeracyonOS project as a whole, and using RawFS (mentioned below) for rapid development. However it will be expanded to support other filesystems and a wider range of configuration options.
In the future I want to make sure it is UEFI compliant as well. BIOS is a deprecated technology and will be removed from Intel chips in the near future. Currently vboot relies heavily on the BIOS for disk reading functions, but much of this can come from UEFI itself. BIOS is currently being used as it is compatible with the legacy/older computers that I use as test benches for OSDev, and for that reason I do not wish to drop BIOS support completely.
Currently vboot supports only a single "file system". This is a "raw" disk, in which the kernel and modules are placed sequentially on the disk with limited meta data pointing to their locations.
Eventually vboot will support the Simple File System, and potentially others.
To get started with vboot, you'll need to ensure you have all of the required tools to build and run the project.
nasm - This is the assembler used to build the bootloader itselfpatch - This is a binary patching tool I wrote available
here.i686-elf-gcc - A cross compiler with an x86 ELF target. This is to build the
test kernel, and is not essential.bochs - The test environment/emulator used for debugging the bootloader.If you have each of these installed then to build the project all you need to
do is run make and a disk image will be produced with the bootloader
installed. Currently the disk image is a RawFS floppy disk image. In time the
default will likely change and customisation options will be added.
To test the bootloader you can run make rawfs-test and the same disk image
will be produced and then launched inside BOCHS.
Contributions to vboot are welcome. Please fork the project, take a look at the issues, make your additions and alterations, then fire a pull request back to the main repo. There is a lot of work to be done.
Copyright (c) 2019 Tom Hancocks
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