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讀入MBR后，從0x7c00h處開始執行
; 下面部分和10h有關中斷，10h中斷用來顯示字符
mov ax, cs
mov es, ax
mov ax, msg
mov bp, ax? ? ? ? ? ? ? ? ? ? ; ES:BP表示顯示字符串的地址
mov cx, msgLen? ? ? ? ? ? ? ? ; CX存字符長度
mov ax, 1301h? ? ? ? ? ? ? ? ; AH=13h表示向TTY顯示字符，AL=01h表示顯示方式（字符串是否包含顯示屬性，01h表示不包含）
mov bx, 000fh? ? ? ? ? ? ? ? ; BH=00h表示頁號，BL=0fh表示顏色
mov dl, 0? ? ? ? ? ? ? ? ? ? ; 列
int 10h
msg: db "hello world, welcome to OS!"
msgLen: equ $ - msg? ? ? ? ? ; 字符串長度
times 510 - ($ - $$) db 0? ? ; 填充剩余部分
dw 0aa55h? ? ? ? ? ? ? ? ? ? ; 魔數，必須有這兩個字節BIOS才確認是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
進入剛解壓的目錄
然后執行命令：./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
s
n
c
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.
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b.
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Then, it can run seccussful as bellow.
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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.
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Debug assembly:
b 0x7c00
s
n
c
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.
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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.
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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.
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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").
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2. First launch qemu. Command as bellow:
"C:\Program Files\qemu\qemu-system-i386.exe" -m 16M -boot a -fda Image -hda hdc-0.11.img -s -S
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3.Confiure the Eclipse.
Refrerence from:https://blog.csdn.net/asdfdypro/article/details/44680813
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?
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3. Then debug as bellow:
?
?
Analyze kerner code
main() is the first C language function. So everything is analyze from here.
Appendix 1 samba-server create
1 首先確認網絡可以相互ping通。
2 終端輸入：apt-get install samba
3 先備份 smb.conf 編輯配置，終端輸入：
cd /etc/samba/ ?
ls
cp smb.conf smb.conf-201x-xx-xx
4nano /etc/samba/smb.conf編輯配置文件
找到[homes]下browseable = no,把no改成yes,因為只有這樣，windows下才能通 過“計算機”看到“homes”共享目錄。----至此，您已經能看到samba共享的目錄了。
當然，以方便調試為目的，所以我們不需要共享homes文件，而是要共享整個根目錄。 所以在[homes]這一段下加入一段，不要在[homes]這一段改，否則出錯，一定要在下面加，如下：
[all]
comment = /
path = /
read only = no
接著在終端輸入：testparm此命令不但能檢查參數是否正確，還能使配置立即生效， 不需要重啟。
5 還要創建用戶，不然只能看到有共享卻無法登錄。在終端輸入：
smbpasswd -a root然后就會提示輸入密碼，其實這個名字可以任意，這里用root是為 了方便記憶，因為我會用最高權限。----到這一步，你就可以登錄到samba共享文件里 了。
6 （可以不要這一步）重啟samba,終端輸入:/etc/init.d/samba restart
Appendix 2 gcc-32bit install
If you system is 64-bit, you should add 32-bit lib support.
sudo apt-get install g++-multilib libc6-dev-i386
then
# gcc boot.o -o boot -m32
