Minimum operating system & linux 0.11

1.Envirment:

1.VM-Envriment:windown 7, vmware(ubuntu-18.04.1-live-server-amd64.iso), SecureCRT(ssh remote ubuntu), samba-server(seeAppendix 1 samba-server create),gcc-32bit(seeAppendix 2 gcc-32bit install, but maybe not need nessesary).

2.Destnation-machine: BOCHS(lastest version form official site), QEMU(lastest version form official site).

Bochs can debug assembly, but can't debug using gdb before recompile. Qemu can using gdb, but can't debug in assembly. So need to install both.

3.Debug-method: TDMGCC(Using its GDB in command line debug).

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

# nasm boot.asm -o boot.bin

4.Debug

1.First step, copy the Example and rename it.

Bochs Example: clickC:\Program Files (x86)\Bochs-2.6.9\dlxlinux\bochsrc.bxrcwill run the dlxlinux, exist after installed.

or goto official site download example.

2.Modify run.bat.

change the current folder name.

and change "bochs" to "bochsdbg"(of couse, if only run without debug, you don't need do this).

3.Modify bochsrc.bxrc.

# what disk images will be used

floppya: 1_44=boot.bin, status=inserted

# choose the boot disk.

boot: a

4.copy boot.bin to current directory. Then will run secced (run mode without debug) as bellow.

5.If in debug mode, can input command.

b 0x7c00

6. "Ctrl+c" or "q" to exit.

5.linux 0.11

source link:https://github.com/yuanxinyu/Linux-0.11(If you searching in bing.com, this is the NO. 1 result.)

Compile:The source could compile directly successful without modify anything in ubuntu-18.04-server.

Using bochs to debug assembly:

1.Copy run.bat from C:\Program Files (x86)\Bochs-2.6.9\dlxlinux , then modify as:

cd "F:\Linux-0.11-master"

"C:\Program Files (x86)\Bochs-2.6.9\bochs" -q -f tools/bochs/bochsrc/bochsrc-hd-win.bxrc

Of cause, if want to debug, modify "bochs" to "bochsdbg".

2. CopyF:\Linux-0.11-master\tools\bochs\bochsrc\*.bxrc, then modify:

a. all "../" modify to bochs install path.

Then, it can run seccussful as bellow.

3. suggest click the "power" button to exit(will auto delete *.lock file). Or not you need to removeF:\Linux-0.11-master\hdc-0.11.img.lock, to let it run successful in second time.

Debug assembly:

b 0x7c00

Using qemu to debug kerner:

usingqemu(download latest from official site). Because bochs must recompile.

Input command: (Cmd copy from source code Makefile,of cause you have to change a little.)

"C:\Program Files\qemu\qemu-system-i386.exe" -m 16M -boot a -fda Image -hda hdc-0.11.img

After input the command, the linux 0.11 would be running successfully.

If you want to debug step by step, just add-S, like following: (Note: qemu will be stop on starting, need more cmd.)

"C:\Program Files\qemu\qemu-system-i386.exe" -m 16M -boot a -fda Image -hda hdc-0.11.img -s -S

Must be "qemu-system-i386", even "qemu-system-x86_64.exe" will be failed.

Open other cmd windows, then input:

F:\Linux-0.11-master>gdb tools/system

(gdb)target remote localhost:1234

(gdb)b main

(gdb)c

(gdb)n

(gdb)s

Then you would see the linux 0.11 is running successfully.

Using eclipse to debug

Eclipse Edition:

download link:https://stackoverflow.com/questions/27418096/where-can-i-download-eclipse-android-bundle

1.New a C project.

NOTE: If linux 0.11 project store in vmware samba server. Couldn't use "\\192.168.220.129\all\home\hui\eclipse-workspace\Linux-0.11-master" as path. Must using "Browse the floder" to setting the path, as below: (Destiation path is "Z:\home\hui\eclipse-workspace").