OS 2023

Guangdong University of Technology Panyu Campus-Next I want to praise a game

Main reference

Our OS mainly refers to the book "RISC-V Architecture Programming and Practice" written by Ben Shu.

Other references:

"Design and Implementation of a 64-bit Operating System"--Tian Yu

riscv-xv6

Instructions for use

make all:Compiled

make run:Start QEMU

make clean: Clear all generated files

make debug: Start QEMU and GDB debugging

Preliminary competition completion status

Due to time limitations, our OS only implements simple interrupt processing, memory management, process scheduling functions, a small part of the file system and a few system calls. Since the bug was not successfully fixed in the end, our virtio driver still has problems and cannot be used. The file system is not fully completed. Therefore, the file system has not given documentation. Please forgive me.

Finals first round

We fixed the bug of the virtio driver, completed a basic file system and only supported elf file loaders that ran static linkers, and supported a small number of syscall and shell commands

Document index

Exception handling and interrupts

Memory management and page table mapping

Process management and scheduling

VFS virtual file system

ELF Loader

Member division of labor

Qu Weikai is responsible for the development of code, Liang Sijun and He Chang are responsible for the debugging of bugs and the writing of documents.

Directory structure

.vscode:vscode相关
bootloader:opensbi生成的sbi固件，由于使用了QEMU默认的sbi固件，因此该文件夹内的opensbi固件未使用
doc:文档说明
include:头文件
	LinkList.h:链表操作
	buf.h:与文件系统相关，用于读写虚拟磁盘的缓冲区
	csr.h:控制寄存器相关
	fs.h:与文件系统相关,由于未完成，目前内容仅有超级块的定义
	io.h:与读取写入相关
	log.h:文件系统相关，磁盘日志
	memory.h:mmu和内存管理相关
	page_table.h:页表相关的宏定义
	plic.h:plic相关
	process.h:进程管理相关
	pt_offset.h:与上下文现场保存相关
	sbi.h:S模式下系统调用opensbi固件接口
	scheduler.h:进程调度相关
	sleeplock.h:睡眠锁
	syscall.h:系统调用
	timer.h:定时器
	trap.h:中断和异常
	uart.h:16550串口控制器
	virtio.h:virtio设备驱动
	VFS.h:虚拟文件系统相关
	fat32.h:fat32文件系统相关
	elf.h:elf格式定义
	elf_loader.h:elf加载器
	sysflags.h:系统调用使用标志
kernel:内核文件夹
	driver:virtio驱动，存在问题
	fs:文件系统相关
	memeory:内存管理和mmu映射
	process:进程管理
	trap:中断和异常
	boot.S:opensbi引导到跳转至内核
	entry.S:汇编相关定义
	linker.ld:链接脚本
	main.c:内核主函数在内
lib:通用库，包含输出和基本函数
usr:与U模式相关

Summarize

Due to time limitations and our limited level, we did not complete the work within the specified time. However, we also learned a lot during this period. The school's operating system class focuses on theory, and the competition gave us a deeper understanding of the operating system from the practical level. During the writing of the work, we also learned a lot of ways to improve development efficiency, such as from the beginning of using the command line gdb debugging to the later learning to use vscode to connect to gdb debugging, which greatly improved the efficiency of our debugging. Although it is very regrettable that we failed to complete and test our OS, the knowledge we learned since the competition has benefited a lot, which has also achieved our goal of participating in the competition.