#!/bin/bash

set -e

# Size in MB
DISK_SIZE=64
ESP_SIZE=100  # Size of EFI System Partition in sectors (100 sectors = ~50KB, enough for our bootloader)

# Create build directory if it doesn't exist
mkdir -p build/bios

# Build stage 1/2 bootloader
./scripts/build_stage1.sh
./scripts/build_stage2.sh

# Create an empty disk image
dd if=/dev/zero of=disk.img bs=1M count=$DISK_SIZE

# Create a partition table
(
echo o # Create a new empty DOS partition table
echo n # Add a new partition (EFI System Partition)
echo p # Primary partition
echo 1 # Partition number 1
echo 2048 # First sector (leaving room for bootloader)
echo +${ESP_SIZE} # Size in sectors
echo t # Change partition type
echo ef # EFI System Partition type

echo n # Add a new partition (Main partition)
echo p # Primary partition
echo 2 # Partition number 2
echo # Default first sector (right after ESP)
echo # Use rest of disk
echo t # Change partition type
echo 2 # Select second partition
echo 0c # FAT32 LBA type
echo a # Make bootable
echo 2 # Select second partition
echo w # Write changes
) | fdisk disk.img > /dev/null 2>&1

# Copy bootloader to disk image
# First stage (MBR)
dd if=build/bios/stage1.bin of=disk.img conv=notrunc bs=446 count=1

# Second stage (right after MBR)
dd if=build/bios/stage2.bin of=disk.img conv=notrunc bs=512 seek=1

# Format ESP partition
ESP_OFFSET=$((2048 * 512))  # First partition starts at sector 2048
mformat -i disk.img@@${ESP_OFFSET} -F -h 255 -t 1 -s 63 -c 1 ::

# Format main partition
MAIN_OFFSET=$(( (2048 + ESP_SIZE) * 512 ))  # Second partition starts after ESP
mformat -i disk.img@@${MAIN_OFFSET} -F -h 255 -t 1 -s 63 -c 1 ::

# Create EFI directory structure in ESP
mmd -i disk.img@@${ESP_OFFSET} ::/EFI
mmd -i disk.img@@${ESP_OFFSET} ::/EFI/BOOT

# When you have the UEFI bootloader ready, uncomment this:
# mcopy -i disk.img@@${ESP_OFFSET} boot/uefi/BOOTX64.EFI ::/EFI/BOOT/