GitFOSS

#!/bin/bash

# Flags

CC_FLAGS="-ffreestanding -nostdinc -nostdinc++ \
					-Wall -Wextra \
					-o ./bin/kernel.bin -target i386-pc-none-elf \
					-I ./kernel/"
LD_FLAGS="-nostdlib -Wl,--oformat=binary,-T./kernel/linker.ld"
CPP_FILES="./kernel/unityBuild.cpp ./build/kernelEntryPoint.o"

# Build

mkdir {bin,build} 2> /dev/null

echo -e "Cleaning..."
rm *.bin *.img *.iso *.o *.vmdk 2> /dev/null

echo -e "\nBuilding..."
nasm ./boot/bootloader.asm -I ./boot/ -o ./bin/bootloader.bin || exit 1
nasm -felf32 ./kernel/entry.asm -I ./kernel/ -o ./build/kernelEntryPoint.o || exit 1

use_crystal_kernel=${USE_CRYSTAL_KERNEL:-true}

if [ "$use_crystal_kernel" = true ]
then
	# Build crystal kernel without stdlib, using the custom prelude, and targeting i386-unknown-linux-elf
	crystal build \
		--no-debug \
		--cross-compile \
		--target i386-unknown-linux-elf \
		-Dkernel \
		--prelude=../prelude.cr \
		-o ./build/kernel ./kernel/kernel.cr || exit 1

	# Link the kernel into an ELF executable, then convert it to a flat binary for the bootloader.
	ld \
	  -m elf_i386 \
	  -nostdlib \
	  -T ./kernel/linker.ld \
	  -o ./bin/kernel.elf ./build/kernelEntryPoint.o ./build/kernel.o || exit 1
	
	# Copy kernel.elf to kernel.bin properly.
	objcopy \
	  -O binary ./bin/kernel.elf ./bin/kernel.bin || exit 1
else
  # Build c++ kernel without stdlib, using the custom prelude, and targeting i386-unknown-linux-elf
	clang++ -v \
	  $CC_FLAGS \
	  $LD_FLAGS \
	  $CPP_FILES || exit 1
fi

cp ./bin/kernel.bin ./iso/boot/kernel.bin || exit 1

./tools/genVDisk \
  --output "crystalos" \
  --floppy \
	--bootloader ./bin/bootloader.bin \
	--kernel ./bin/kernel.bin || exit 1

# Run

echo -e "\nRunning..."

use_vnc=${USE_VNC:-false}

if [ "$use_VNC" = true ]
then
  qemu-system-i386 -drive if=floppy,index=0,format=raw,file=crystalos.img || exit 1
else
  qemu-system-i386 -drive if=floppy,index=0,format=raw,file=crystalos.img -display curses || exit 1
fi

exit 0