Minimum operating system with QEMU, but no debug
1.Envirment:
(see appendix Envriment create)
2.source
; 文件名 boot.asm
org 7c00h ; BIOS读入MBR后,从0x7c00h处开始执行
; 下面部分和10h有关中断,10h中断用来显示字符
mov ax, cs
mov es, ax
mov ax, msg
mov bp, ax ; ES:BP表示显示字符串的地址
mov cx, msgLen ; CX存字符长度
mov ax, 1301h ; AH=13h表示向TTY显示字符,AL=01h表示显示方式(字符串是否包含显示属性,01h表示不包含)
mov bx, 000fh ; BH=00h表示页号,BL=0fh表示颜色
mov dl, 0 ; 列
int 10h
msg: db "hello world, welcome to OS!"
msgLen: equ $ - msg ; 字符串长度
times 510 - ($ - $$) db 0 ; 填充剩余部分
dw 0aa55h ; 魔数,必须有这两个字节BIOS才确认是MBR
3.Compile
If till not install nasm, should install first.
nasm install on ubuntu
1.Download source code: https://www.nasm.us/pub/nasm/releasebuilds/
2.tar zxvf nasm-2.10.07.tar.gz
进入刚解压的目录
然后执行命令:./configure
make
sudo make install
NOTE: Using "apt install nasm" to install is failled.
nasm usage
If only want to run without debugging, only input bellow:
# nasm boot.asm -o boot.bin
If want gdb can regcnise the format, should do more, convert it into ELF file format.
# nasm -f elf -g boot.asm -o boot.o
# gcc -c boot.o -o boot
If the gcc is bit32, should install some lib, as bellow:
sudo apt-get install g++-multilib libc6-dev-i386
then
# gcc boot.o -o boot -m32
4.Command line Debug
NOTE: Must copy the linux 0.11 project to windows disk, cannot in samba server, or not can't debug.
QEMU version: Download latest version from official site.
Input command:
"C:\Program Files\qemu\qemu-system-x86_64.exe" boot.bin
"C:\Program Files\qemu\qemu-system-x86_64.exe" -m 16M -boot a -fda boot.bin -s -S
-s wait gdb connection to port 1234
'-S' means freeze CPU at startup (Can be remove to run directly), so you can debug step byt step.
After input the command, the linux 0.11 would be running succe
Open other cmd windows, then input:
F:\Linux-0.11-master>gdb Image
(gdb) target remote localhost:1234
(gdb) b *0x7c00
(gdb)c
(gdb)x /16b 0x7df0 //观察0x7DFE和0x7DFF的值是否为0x55,0xAA
(gdb)
Then you would see the linux 0.11 is running successfully.
Can using "Ctrl+C" to stop running.
Appendix 1 Envriment create
1.VM-Envriment:windown 7, vmware(ubuntu-18.04.1-live-server-amd64.iso), SecureCRT(ssh remote ubuntu), samba-server(see appendix samba-server create).
2.Destnation-machine: QEMU(download from official site),
3.Debug-method: TDMGCC(Using its GDB in command line debug).
Appendix 2 samba-server create
1 首先确认网络可以相互ping通。
2 终端输入:apt-get install samba
3 先备份 smb.conf 编辑配置,终端输入:
cd /etc/samba/
ls
cp smb.conf smb.conf-201x-xx-xx
4 nano /etc/samba/smb.conf 编辑配置文件
- 找到[homes]下 browseable = no, 把no 改成 yes, 因为只有这样,windows下才能通 过“计算机”看到“homes”共享目录。----至此,您已经能看到samba共享的目录了。
- 当然,以方便调试为目的,所以我们不需要共享homes文件,而是要共享整个根目录。 所以在[homes]这一段下加入一段,不要在[homes]这一段改,否则出错,一定要在下面加,如下:
[all]
comment = /
path = /
read only = no
接着在终端输入:testparm 此命令不但能检查参数是否正确,还能使配置立即生效, 不需要重启。
5 还要创建用户,不然只能看到有共享却无法登录。在终端输入:
smbpasswd -a root 然后就会提示输入密码,其实这个名字可以任意,这里用root是为 了方便记忆,因为我会用最高权限。----到这一步,你就可以登录到samba共享文件里 了。
6 (可以不要这一步)重启samba,终端输入: /etc/init.d/samba restart