#!/bin/bash

set -e

# set -x # turn on command printing

# config

TARGET="rust_os"

# some constants

PATH=$PATH:$HOME/.cargo/bin

# prepare for build

mkdir -p build

echo "Compiling source files..."

echo "* bootloader"

# compile bootloader

nasm src/boot/stage0.asm -f bin -o build/stage0.bin

nasm src/boot/stage1.asm -f bin -o build/stage1.bin

nasm src/boot/stage2.asm -f bin -o build/stage2.bin

echo "* kernel entry point"

# compile kernel entry point

nasm -f elf64 src/entry.asm -o build/entry.o

echo "* kernel"

# compile kernel (with full optimizations)

# RUST_TARGET_PATH=$(pwd) xargo build --target $TARGET --release

RUSTFLAGS=-g RUST_TARGET_PATH=$(pwd) xargo rustc --target $TARGET --release -- -C opt-level=s

echo "* kernel assembly routines"

mkdir -p build/asm_routines/

for fpath in src/asm_routines/*.asm

do

filename=$(basename "$fpath") # remove path

base="${filename%.*}" # get basename

nasm -f elf64 "$fpath" -o "build/asm_routines/$base.o"

done

echo "* D7_StaticFS cli tools"

( cd libs/d7staticfs/ && cargo build --release )

echo "Linking objects..."

# link (use --print-gc-sections to debug)

# ld -z max-page-size=0x1000 -T build_config/linker.ld -o build/kernel.bin build/entry.o target/$TARGET/release/librust_os.a build/asm_routines/*.o

# ld -z max-page-size=0x1000 --unresolved-symbols=ignore-all -T build_config/linker.ld -o build/kernel.bin build/entry.o target/$TARGET/release/librust_os.a build/asm_routines/*.o

# ld -z max-page-size=0x1000 --gc-sections --print-gc-sections -T build_config/linker.ld -o build/kernel.bin build/entry.o target/$TARGET/release/librust_os.a build/asm_routines/*.o

ld -z max-page-size=0x1000 --gc-sections -T build_config/linker.ld -o build/kernel.bin build/entry.o target/$TARGET/release/librust_os.a build/asm_routines/*.o

cp build/kernel.bin build/kernel_unstripped.bin

strip build/kernel.bin

echo "Cheking boundries..."

# image size check

imgsize=$(wc -c build/kernel.bin | xargs -n 1 2>/dev/null | head -n 1)

echo "imgsize: $imgsize"

maxsize=400 # size in blocks

toobig=$(python3 -c "print(int($imgsize//0x200>$maxsize))")

if [ $toobig -eq 1 ]

then

echo "Kernel image seems to be too large."

exit 1

fi

echo "Creating disk image..."

DISK_SIZE_BYTES=$(python3 -c 'print(0x200*0x800)') # a disk of 0x800=2048 0x200-byte sectors, 2**20 bytes, one mebibyte

DISK_SIZE_SECTORS=$(python3 -c "print($DISK_SIZE_BYTES // 0x200)")

# create disk

echo "* create disk"

dd "if=/dev/zero" "of=build/disk.img" "bs=512" "count=$DISK_SIZE_SECTORS" "conv=notrunc"

echo "* copy boot stages"

dd "if=build/stage0.bin" "of=build/disk.img" "bs=512" "seek=0" "count=1" "conv=notrunc"

dd "if=build/stage1.bin" "of=build/disk.img" "bs=512" "seek=1" "count=1" "conv=notrunc"

dd "if=build/stage2.bin" "of=build/disk.img" "bs=512" "seek=2" "count=1" "conv=notrunc"

echo "* copy kernel"

dd "if=build/kernel.bin" "of=build/disk.img" "bs=512" "seek=3" "conv=notrunc"

echo "* write filesystem"

./libs/d7staticfs/target/release/mkimg build/disk.img $(($imgsize/0x200+4)) $(< build_config/staticfs_files.txt)

echo "Saving objdump..."

objdump -CShdr -M intel build/kernel_unstripped.bin > objdump.txt

echo "Saving readelf..."

readelf -e build/kernel_unstripped.bin > readelf.txt

# TODO? clean?

echo "Done"