first_simple_rtos

first simple rtos with qemu vm (realview pb a8)
Study Book: "도전! 임베디드 OS 만들기"
(https://github.com/navilera/Navilos)

1. booting, exception vector table, reset handler, linker, Makefile, ...
2. uart, console, printf
3. interrupt, gic, uart interrupt
4. timer, delay

Environments

• Host OS
  • Ubuntu 22.04
• Machine
  • vm: qemu-system-arm / realview-pb-a8
  • sudo apt install qemu-system-arm
• Cross platform (toolchain)
  • toolchain: arm-none-eabi-
  • sudo apt install gcc-arm-none-eabi
  • gdb: gdb-multiarch
  • sudo apt install gdb-multiarch

Build

• make

Debugging

1. make debug
2. make gdb
   1. target remote:1234
   2. file build/navilos.axf

Run & Quit

• make run
• make kill (in another terminal)

Directory tree

first_simple_rtos/  
├── boot
│   ├── handler.c
│   └── realview_pb
│       ├── entry.S
│       └── main.c
├── docs
│   ├── gdb.md
│   └── images
│       └── gdb_with_vim.png
├── hal
│   └── realview_pb
│       ├── interrupt.c
│       ├── regs.c
│       ├── timer.c
│       └── uart.c
├── include
│   ├── armcpu.h
│   ├── armv7_ar.h
│   ├── hal
│   │   ├── interrupt.h
│   │   ├── timer.h
│   │   └── uart.h
│   ├── mach
│   │   └── realview_pb
│   │       ├── interrupt.h
│   │       ├── memory_map.h
│   │       ├── sysctrl.h
│   │       ├── timer.h
│   │       └── uart.h
│   ├── mmio.h
│   ├── stdarg.h
│   ├── stdint.h
│   ├── stdio.h
│   └── stdlib.h
├── lib
│   ├── armcpu.c
│   ├── stdio.c
│   └── stdlib.c
├── Makefile
├── navilos.ld
└── README.md

• All header files are under include/

Documents

• RealView Platform Baseboard for Cortex-A8
  • User Guide
    • Programmer's Reference
• PrimeCell UART (PL011) Technical Reference Manual
  • https://developer.arm.com/documentation/ddi0183/g?lang=en
• ARM Dual-Timer Module (SP804) Technical Reference Manual
  • https://developer.arm.com/documentation/ddi0271/d
• GCC Link Options
  • https://gcc.gnu.org/onlinedocs/gcc/Link-Options.html