Metamorphic is a technique to obfuscate a binary and change the opcode sequence and create new samples with same functionality. In my case, I have some elf binary of ARM processor type and their source code is not accessible. Is there any way to obfuscate them and create new samples with same functionality?
I don't have the reputation to comment, and can only post this as an answer.
I'm sure this question will run into moderation problems as it sounds like you have read the binary out of a micro-controller and wish to clone the binary in such a way that it circumvents copyright. Correct me if I am wrong, and also provide more information (which processor etc).
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i want to create new library for my e-paper using atmega32 and eclipse enviroment. What do i have to know about it moreover how it works. I dont want to use arduino libraries, want to write it on my own. How to best start making it? I know how to use SPI, what commands do i have to send to display, but do i have to have any drivers which are necessarily? Is any possibilty to program it using only this module:
https://www.waveshare.com/1.54inch-e-paper-module-b.htm
and SPI? Or it is necessary to have some drivers to do it?
Your question a little bit strange, because "driver" is usually piece of code, written by a third person. So, answer is yes - it is always possible to do it from scratch, without using third-side software.
First what you need to know is what type of controller being used in that display, to get technical documentation (datasheet). Unfortunately, there is no such information, but there is a link to the specification document: https://www.waveshare.com/w/upload/9/9e/1.54inch-e-paper-b-specification.pdf
Read it carefully. For example at page 8 you can find the list of commands, which are used to control the display, and below the detailed description of the commands.
At pages 24, 25 you can find initialization sequence, and reference flowchart.
If any doubts, you can download and investigate how third-party libraries are done. For example here: https://github.com/waveshare/e-Paper
I'm encoding images as video using FFmpeg using custom C code rather than linux commands because I am developing the code for an embedded system.
I am currently following through the first dranger tutorial and the code provided in the following question.
How to encode a video from several images generated in a C++ program without writing the separate frame images to disk?
I have found some "less abstract" code in the following github location.
https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/encode_video.c
And I plan to use it as well.
My end goal is simply to save video on an embedded system using embedded C source code, and I am coming up the curve too slowly. So in summary my question is, Does it seem like I am following the correct path here? I know that my system does not come with hardware for video codec conversion, which means I need to do it with software, but I am unsure if FFmpeg is even a feasible option for embedded work because I am yet to compile.
The biggest red flag for me thus far is that FFmpeg uses dynamic memory allocation. I am unfamiliar with how to assess the amount of dynamic memory that it uses. This is very important information to me, and if anyone is familiar with the amount of memory used or how to assess it before compiling, I would greatly appreciate the input.
After further research, it seems to me that encoding video is often a hardware intensive task that can use multiple processors and mega-gigbyte sizes of RAM. In order to avoid this I am performing a minimal amount of compression by utilizing the AVI format.
I have found that FFmpeg can't readily be utilized for raw-metal embedded systems because the initial "make" of the library sets up configuration settings specific to the computer compiling, which conflicts with the need to cross compile. I can see that there are cross compilation flags available, but I have not found any documentation describing how to use them. Either way I want to avoid big heaps and multi-threading, so I moved on.
I decided to look for more basic source code elsewhere. mikekohn.net/file_formats/libkohn_avi.php Is a great resource for very basic encoding without any complicated library dependencies or multi-threading. I am yet to implement, so no guarantees, but best of luck. This is actually one of the only understandable encoding source codes that I have found for image to video applications, other than https://www.jonolick.com/home/mpeg-video-writer. However, Jon Olick's source code uses lossy encoding and a minimum framerate (inherent to MPEG), both of which I am trying to avoid.
I´m searching for a way to encrypt my C source files. That way, I can handle it to some project partners. I don´t want them to see my code but I want them to use the functions I implemented so they can flash it on a microcontroller.
Is it even possible to encrypt a source file so J-Link can flash it?
I got told to look up for DLL but I don´t know if a DLL would help in this situation.
For software, I use Dave v4 as IDE and FreeRTOS as firmware. For Hardware I use a XMC4700 Relax Kit.
DLLs won't help,
because your platform (presumably) lacks a dynamic loader. It might be possible to create one, but it doesn't worth the trouble, because you can just
ship the object files.
For that to work, you need a copy of your partner's compiler. Compile your sources exactly as they'd do it (with the same compiler options), and ship the resulting object files along with the headers needed to use it.
This appears to be an XY problem. You want to protect your intellectual property, and you think you can use encryption to do that. You asked about encryption, when you should have asked about protecting your intellectual property.
Encryption isn't very useful for protecting intellectual property. If your clients machine can decrypt the code to run it then your client can decrypt the code. If your client can't decrypt the code the client can't run it. Either way, problems are introduced...
The solution to your problem is the legal system. Use that to protect your intellectual property, instead.
I'm writing a kernel for educational purposes and I want to integrate a disassembler into my kernel.
Since I'm going to integrate it into the kernel I want it to be very small and simple,
i.e I only need it to receive a memory address and return the assembly instruction at that address.
I've looked for an open source that can do that but all I found is big libraries which are way too big and complicated.
I'm talking about a few (2-4) source code files that does not require a complicated installation/integration and that is very limited in it's abilities and only provide the very basic functionalities.
Does anybody know such an open source (for C of course)?
You might have heard of the radare2 project (github). It includes rasm which is a quite simple disassembler.
You can find their code in their github repository.
If you're using GNU gcc & binutils, you can just use objdump. The way I usually use it is:
objdump -dSr my_file.o > my_file.s
I'm writing my own operating system, and so far I'm only really able to write it in assembly, because I don't really understand how I would set it up with multiple files/languages. I've written bootloaders with executable code in them before, but what I don't understand is how to make the bootloader aware of other files outside of itself. How would I be able to write a bootloader in assembly and then tell it to load, say, a kernel written in C in a different file? Do I have to bundle the .o files from the compilation of the kernel into the fdd image and tell the bootloader to load/execute them or is it more complicated than that?
Since it looks like you're trying to get the hang of system bring up it might be worthwhile to take a look at some "smaller" embedded systems to get a feel for what goes on once power is applied/chip comes out of reset. Take a look at U-Boot here: http://www.denx.de/wiki/U-Boot
It is a very popular bootloader especially for embedded systems and can launch a variety of OS's. The mainline supports a ton of different configurations as well. I think it is relatively straight forward to follow what happens during power up if you are comfortable with C.
To answer your question more specifically for instance with U-Boot you can either build parameters into the u-boot image as to where you are going to load your code, it can read where you image file is stored from a configuration file on powerup, u-boot can load a configuration automatically from your network somewhere, you can even tell u-boot where and what to load from its command line interface. Take a look and see if you have any further questions.