任务2

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cd pintos/src/threads
cd build
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pintos --bochs --gdb -- run loader.S

换一个命令行

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cd pintos/src/threads
cd build
pintos-gdb kernel.o
target remote localhost:1234
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break *0x7c00

开始执行代码，直到断点处停止：

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c

一旦程序停在断点处，你可以使用 x/i 命令来反汇编当前指令：

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x/i $pc

连续查看3条

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x/3i 0xffff0 + 1

练习4

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cd pintos/src/threads
cd build
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pintos --bochs --gdb -- run start.S

换一个命令行

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pintos-gdb kernel.o
target remote localhost:1234

//打断点
break pintos_init
//运行
c
//查看init_page_dir[pd_no(ptov(0))]的值：

print/x init_page_dir[pd_no(ptov(0))]
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break palloc_get_page
c
backtrace
print/x init_page_dir[pd_no(ptov(0))]

练习5

修改init.c

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if (*argv != NULL) run_actions(argv);
else{
    // TODO: no command line passed to kernel. Run interactively;
    console_init();
    while (true){
        char buffer[1024];
        int index = 0;
        printf("OS2021> ");
        while (true){
            char c = input_getc();
            if (c == '\r' || c == '\n'){
                buffer[index] = '\0';
                if (strcmp(buffer, "msk") == 0)
                    printf("\nYour Name: [msk]\nYour ID: [202110120428]\n");
                else if (strcmp(buffer, "exit") == 0)
                    shutdown_power_off();
                else
                    printf("\nInvalid command\n");
                memset(buffer, 0, sizeof(buffer));
                index = 0;
                break;
            }
            else if (c > ' ' && c < '~'){
                printf("%c",c);
                buffer[index++] = c;
            }
        }
    }
}

每次修改完都要 make all 进行编译，形成 .o 文件

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cd pintos/src/threads
cd build
make all
pintos --