Limine Bare Bones: Difference between revisions

This article will demonstrate how to write a small Limine-compliant x86-64 kernel in (GNU) [[C]], and boot it using the [[Limine]] bootloader.

 

 

 

For this example, we will create these 2 files to create the basic directory tree of our project:

This is the kernel "main".

 

#include <stdint.h>

#include <stddef.h>

}

 

 

===linker.ld===

This is going to be our linker script describing where our sections will end up in memory.

 

/* Tell the linker that we want an x86_64 ELF64 output file */

OUTPUT_FORMAT(elf64-x86-64)

}

 

 

==Building the kernel and creating an image==

GNU make will process it.

 

# Nuke built-in rules and variables.

override MAKEFLAGS += -rR

mkdir -p "$$(dirname $@)"

$(KLD) $(OBJ) $(KLDFLAGS) -o $@

 

# Include header dependencies.

clean:

rm -rf bin obj

 

===limine.cfg===

This file is parsed by Limine and it describes boot entries and other bootloader configuration variables. Further information [https://github.com/limine-bootloader/limine/blob/trunk/CONFIG.md here].

 

# Timeout in seconds that Limine will use before automatically booting.

TIMEOUT=5

 

KERNEL_PATH=boot:///boot/myos

 

===Compiling the kernel===

These are shell commands. They can also be compiled into a script or Makefile.

 

# Download the latest Limine binary release for the 7.x branch.

git clone https://github.com/limine-bootloader/limine.git --branch=v7.x-binary --depth=1

# Install Limine stage 1 and 2 for legacy BIOS boot.

./limine/limine bios-install image.iso

 

====Creating a hard disk/USB drive image====

These are shell commands. They can also be compiled into a script or Makefile.

 

# Create an empty zeroed-out 64MiB image file.

dd if=/dev/zero bs=1M count=0 seek=64 of=image.hdd

mcopy -i image.hdd@@1M limine/BOOTX64.EFI ::/EFI/BOOT

mcopy -i image.hdd@@1M limine/BOOTIA32.EFI ::/EFI/BOOT

 

==Conclusions==