#!/bin/bash
# Complete build script for SoraOS with 2-stage bootloader

set -e  # Exit on any error

echo "==================================="
echo "    SoraOS Build System v1.0"
echo "==================================="
echo ""

# Colors
GREEN='\033[0;32m'
BLUE='\033[0;34m'
YELLOW='\033[1;33m'
NC='\033[0m'

# Prepare build environment 
echo -e "Preparing build environment...${NC}" 
echo -e "Creating Folders${NC}"
mkdir -p bin obj boot include
echo -e "${GREEN}✓${NC} Folders created.${NC}"

# Step 1: Assemble Stage 1 bootloader (MBR - 512 bytes)
echo -e "${BLUE}[1/6]${NC} Assembling Stage 1 bootloader (MBR)..."
nasm -f bin ./boot/boot.asm -o ./bin/boot.bin

# Step 2: Assemble Stage 2 bootloader (extended loader)
echo -e "${BLUE}[2/6]${NC} Assembling Stage 2 bootloader..."
nasm -f bin ./boot/elevator.asm -o ./bin/elevator.bin

# Step 3: Assemble kernel entry point
echo -e "${BLUE}[3/6]${NC} Assembling kernel entry..."
nasm -f elf64 ./boot/kernel.asm -o ./obj/kernel.asm.o

# Step 4: Compile kernel C code
echo -e "${BLUE}[4/6]${NC} Compiling kernel..."
gcc -ffreestanding -c kernel.c -o ./obj/kernel.c.o -mcmodel=large -mno-red-zone -fno-pic -fno-pie -static -fno-stack-protector -nostdlib -mno-mmx -mno-sse -mno-sse2 -m64

# Step 5: Link kernel
echo -e "${BLUE}[5/6]${NC} Linking kernel..."
ld -T linker.ld -o ./bin/kernel.bin ./obj/kernel.asm.o ./obj/kernel.c.o --oformat binary --nostdlib

# Step 6: Create OS image
echo -e "${BLUE}[6/6]${NC} Creating OS image..."
cat ./bin/boot.bin ./bin/elevator.bin ./bin/kernel.bin > os.bin

# Pad to floppy size (1.44MB)
# FIX: Uncomment the line below if you want to ensure the image is exactly 1.44MB 
#
truncate -s 1440K os.bin

echo ""
echo -e "${GREEN}✓ Build complete!${NC}"
echo ""
echo "==================================="
echo "File Layout:"
echo "==================================="
echo "Sector 1:    Stage 1 (MBR)"
echo "Sectors 2-6: Stage 2 (Extended Bootloader)"
echo "Sectors 7+:  Kernel"
echo ""

# Show sizes
echo "File Sizes:"
printf "%-15s %10s\n" "File" "Size"
printf "%-15s %10s\n" "----" "----"
printf "%-15s %10d bytes\n" "boot.bin" $(stat -f%z ./bin/boot.bin 2>/dev/null || stat -c%s ./bin/boot.bin 2>/dev/null)
printf "%-15s %10d bytes\n" "elevator.bin" $(stat -f%z ./bin/elevator.bin 2>/dev/null || stat -c%s ./bin/elevator.bin 2>/dev/null)
printf "%-15s %10d bytes\n" "kernel.bin" $(stat -f%z ./bin/kernel.bin 2>/dev/null || stat -c%s ./bin/kernel.bin 2>/dev/null)
printf "%-15s %10d bytes\n" "os.bin" $(stat -f%z os.bin 2>/dev/null || stat -c%s os.bin 2>/dev/null)
echo ""

echo -e "${YELLOW}Running QEMU...${NC}"
echo "==================================="
echo "Press Ctrl+C to exit QEMU"
echo ""

qemu-system-x86_64 -drive format=raw,file=os.bin -no-reboot


echo -e "${GREEN}Done!${NC}"