Packet Generator Tool

PackETH: ethernet packet generator
It can generate any raw packet.

Download from:
http://packeth.sourceforge.net/
http://sourceforge.net/projects/packeth/
The default file is for Windows, and Linux version need to Click on Browser all link

Install:
cd to packet directory
./configure
make
sudo make install

Usage:
Run it as root
Define packet header, payload, and interface, and click send

How to Limit the Amount of Memory Available to OS

Linux:

set the mem=2000m as the boot arguments, then the Linux only use first 2000MB memory. If the total RAM is 2G, it reserves 48MB.
http://fengweizhang.blogspot.com/2012/06/boot-arguments-on-linux.html


Windows:

Add line
MaxPhyPage=0x7D000 
at [386enh] section of C:\WINDOWS\system.ini
0x7D000 * 4KB = 2000MB
http://support.microsoft.com/kb/181862

Boot Arguments on Linux

http://tldp.org/HOWTO/BootPrompt-HOWTO-3.html

The `mem=' Argument

This argument has several purposes: The original purpose was to specify the amount of installed memory (or a value less than that if you wanted to limit the amount of memory available to linux).
The next (and hardly used) purpose is to specify mem=nopentium which tells the Linux kernel to not use the 4MB page table performance feature. If you want to use it for both purposes, use a separate mem= for each one.
The original BIOS call defined in the PC specification that returns the amount of installed memory was only designed to be able to report up to 64MB. (Yes, another lack of foresight, just like the 1024 cylinder disks... sigh.) Linux uses this BIOS call at boot to determine how much memory is installed. A newer specification (e820) allows the BIOS to get this right on most machines nowadays. If you have more than 64MB of RAM installed on an older machine, you can use this boot argument to tell Linux how much memory you have. Here is a quote from Linus on the usage of the mem= parameter.
``The kernel will accept any `mem=xx' parameter you give it, and if it turns out that you lied to it, it will crash horribly sooner or later. The parameter indicates the highest addressable RAM address, so `mem=0x1000000' means you have 16MB of memory, for example. For a 96MB machine this would be `mem=0x6000000'. If you tell Linux that it has more memory than it actually does have, bad things will happen: maybe not at once, but surely eventually.''
Note that the argument does not have to be in hex, and the suffixes `k' and `M' (case insensitive) can be used to specify kilobytes and Megabytes, respectively. (A `k' will cause a 10 bit shift on your value, and a `M' will cause a 20 bit shift.) A typical example for a 128MB machine would be "mem=128m".
In some cases, the memory reported via e820 can also be wrong, and so the mem=exactmap was added. You use this in conjunction with specifying an exact memory map, such as:

---

        mem=exactmap mem=640K@0 mem=1023M@1M

---

for a 1GB machine with the usual 384k of ISA memory mapped I/O space excluded from use.

Reference: Convert Assembly to Opcode

http://ref.x86asm.net/

Backup by using rsync in Linux and Windows

In Linux: man rsync


rsync -r ../WorkSpace username@servername:/home/username/backup-machine

In Windows, you can use cygwin

1. Install cygwin

2. search rsync, and install rsync package

3. run rsync

rsync -r /cygdrive/c username@servername:/home/username/back-windows

Modify Executable in Windows

1. Download Hex Editor: HxD
http://download.cnet.com/HxD-Hex-Editor/3000-2352_4-10891068.html

2. Open the Executable by using HxD

3. Go the executable place you want to modify
For example (nasm format) :
66 BA 2F 05 : mov dx, 0x52f
66 EE : out dx, al

Assembly in Windows

1. Compiler: MASM 
download: http://www.masm32.com/
install it
it has an masm editor
it use NASM assembly, please use pcasm for reference
http://www.drpaulcarter.com/pcasm/
But it doesn't have the IO instruction in the book


2. Start with hello world program

include \masm32\include\masm32rt.inc  
.data
MyTitle db "ASM is Fun!",0
MyText db "I hope you're learning!",0
.codestart:
push 0
push offset MyTitle
push offset MyTextpush 0
call MessageBoxA
call ExitProcess
end start



URL: http://computertech.createmybb3.com/showthread.php?tid=105
http://www.youtube.com/watch?v=gklpZIVuTBY



3. Write your own program

.386
.model flat,stdcall
.code
start
mov dx, 1327
out dx, ax
end start



This program write port 0x52f It looks like MASM cannot use hex because I get compile error.



4. Run the Program 

AllowIo.exe WritePort.exe /a
write to port in Windows, please see my another article
http://fengweizhang.blogspot.com/2012/04/user-program-write-to-io-ports-on.html