#!/bin/bash

# -x -> trace: print every command
# -u -> exit if undefined variables are used
# -e -> exit if an error occurs
set -xue

QEMU=qemu-system-riscv32

# Compile
CC=clang
# -ffreestanding: do not use stdlib of the host environment
# -fuse-ld=lld: LLVM linker
# -fno-stack-protector: disable stack protection
# -Wl,-Tkernel.ld: linker script
# -Wl,-Map=kernel.map: output a map file (linker allocationr result)
CFLAGS="-std=c11 -O2 -g3 -Wall -Wextra --target=riscv32-unknown-elf -fuse-ld=lld -fno-stack-protector -ffreestanding -nostdlib"

$CC $CFLAGS -Wl,-Tkernel.ld -Wl,-Map=kernel.map -o kernel.elf \
    src/kernel.c \
    src/io.c \
    src/memory.c \
    src/string.c

# Run QEMU
# -machine virt: generic riscv platform
# -bios default: load the default firmware (OpenSBI)
# -nographic: disable VGA, everything on console
# -serial mon:stdio: serial port is connected to terminal's stdin/stdout
# --no-reboot: do not reboot if there's panic/shutdown/crash
$QEMU -machine virt -bios default -nographic -serial mon:stdio --no-reboot \
    -kernel kernel.elf

# Press Ctrl+A and then C to enter QEMU debug console and quit with `q`