Series Summary

Key points

• Toolchain: always use riscv64-unknown-elf-gcc for RV32 bare-metal builds.
• Runtime: _start sets up the stack and clears .bss; no libc is assumed.
• QEMU: run everything on qemu-system-riscv32 with -bios none and -kernel.
• Debugging: GDB + QEMU provides breakpoints, watchpoints, and instruction stepping.
• MMIO: UART output at 0x10000000 is the simplest reliable output path.

Índice

• ABI: ABI RV32 + tipos em C
• Assembly básico: Instruções básicas de assembly RISC-V
• Depuração: Debug de RV32 com QEMU + GDB
• ELF: Internals de ELF e Binutils
• Linker script: Scripts de linker e mapas de memória
• MMIO/UART: Interfaces no QEMU: UART e conceitos de MMIO
• Otimização: C → ASM: otimizações e volatile
• Rodar QEMU: Configurando a toolchain e o QEMU
• Tracing: Análise dinâmica com tracing no QEMU

Exercises

1. Choose one program and add a new function, then verify the call frame in GDB.
2. Modify src/uart.c to add a uart_puthex8 helper and use it in a chapter example.
3. Replace one C example with a pure assembly version.

Summary

You now have a complete bare-metal RV32 workflow that runs entirely under QEMU. You can build, run, trace, and debug without any physical hardware.