This book assumes you're using a UNIX or UNIX like OS such as macOS or Ubuntu. If you're on Windows, install Windows Subsystem for Linux (WSL2) and follow the Ubuntu instructions.
Install development tools
macOS
Install Homebrew and run this command to get all tools you need:
brew install llvm lld qemu
Ubuntu
Install packages with apt:
sudo apt update && sudo apt install -y clang llvm lld qemu-system-riscv32 curl
Also, download OpenSBI (think of it as BIOS/UEFI for PCs):
curl -LO https://github.com/qemu/qemu/raw/v8.0.4/pc-bios/opensbi-riscv32-generic-fw_dynamic.bin
When you run QEMU, make sure
opensbi-riscv32-generic-fw_dynamic.binis in your current directory. If it's not, you'll see this error:qemu-system-riscv32: Unable to load the RISC-V firmware "opensbi-riscv32-generic-fw_dynamic.bin"
Other OS users
If you are using other OSes, get the following tools:
bash: The command-line shell. Usually it's pre-installed.tar: Usually it's pre-installed. Prefer GNU version, not BSD.clang: C compiler. Make sure it supports 32-bit RISC-V CPU (see below).lld: LLVM linker, which bundles complied object files into an executable.llvm-objcopy: Object file editor. It comes with the LLVM package (typicallyllvmpackage).llvm-objdump: A disassembler. Same asllvm-objcopy.llvm-readelf: An ELF file reader. Same asllvm-objcopy.qemu-system-riscv32: 32-bit RISC-V CPU emulator. It's part of the QEMU package (typicallyqemupackage).
To check if your
clangsupports 32-bit RISC-V CPU, run this command:$ clang -print-targets | grep riscv32 riscv32 - 32-bit RISC-VYou should see
riscv32. Note pre-installed clang on macOS won't show this. That's why you need to install anotherclangin Homebrew'sllvmpackage.
Setting up a Git repository (optional)
If you're using a Git repository, use the following .gitignore file:
.gitignore/disk/* !/disk/.gitkeep *.map *.tar *.o *.elf *.bin *.log *.pcap
You're all set! Let's start building your first operating system!