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I'm currently developing an embedded controller, which will be connected to a potentially hostile environment. Since the Controller is quite limited (~50 MHz, ~16 KiB RAM), I do not have the luxury of an operating system which can help me with memory protection.
What is considered best practices for securing an embedded device? I know of techniques like stack guards, but since I'm not familiar with embedded development, I'm looking for some kind of guidance.
Edit: I'm using an ATSAMD21G18, which does not have an MMU. It's the same as used on many Arduinos. The controller will be conntected to a public bus (as in wiring, not the transportation method) thus I cannot assume anything about the behaviour of other bus members.
I am however not trying to protect IP, e.g. I'm not worried about somebody figuring out the contents of my controller. It's more about application security, e.g. how do I limit the harm done by somebody trying to take over my controller by exploiting e.g. buffer overruns.
Automotive MCU:s typically have a "copy cat" protection which blocks any form of debugger access - you can't read anything out of the MCU or debug it while this is active, you have to erase everything.
Check out MCU:s by silicon vendors with a lot to automative customers, such as NXP/Freescale or Renesas.
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I have few doubts on database storage techniques:
How to store CPU usage activity to consider it for later use?
How to store RAM usage variation for a certain amount of time?
Similarly, how to store Disk usage?
All these data will be later used for ANOVA test.
I am trying to get these values from a c# application which will be monitoring the activities of a system for a certain amount of time.
A much better idea is to use the Performance Manager built into Windows (perfmon.exe). You can set it to record many performance items including the three you mention (CPU and RAM by program as well as in total). There is also a free analyser called PAL at Codeplex which can help you set the recording and then analyse it for you.
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Technically UEFI provides a lot of functionality which is part of the groundwork of an operating system, such as a file system. In a way, it is a shame that everything gets discarded and reimplemented by the operating system in the process of booting.
I am wondering how much of a functional operating system would it to implement it as a simple a UEFI application. I am thinking of a graphical user interface and multitasking. Using FAT32 as a file system, UEFI should do well for a lot of purposes and so should identity mapped memory. It would make a very lean and simple operating system, probably even without the need for installation.
The question is where would the limits be of what is feasible to provide in terms of functionality of a full fledged operating system? Any suggestions?
Please don't.
UEFI has no isolation and exposes all it's state, drivers, handles and protocols directly to the user, like DOS did back then.
There is no virtual addresses, there is no user mode, there is no privilege levels, but there is a bunch of code written with an intent to work fast and be discarded fast. Any UEFI application that interacts with the user is a potential security disaster waiting to happen.
Call gRT->ExitBootServices as soon as possible and boot Linux, QNX, L4, Redox or whatever proper OS kernel you like.
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Is there anything as low level as that on any Linux distribution? My overall goal is to redirect the message (instruction) meant for the GPU.
That means I would have to be able to program a driver between the CPU and the GPU which redirects any message to where I'd like (like a packet sniffer, but for GPU instructions and one that would stop the info there).
Is there any native Linux support for this kind of thing? Where do I start and what OS is most recommended for this kind of access?
You would need to modify the GPU driver. There you can insert logging or whatever other redirection you have in mind. Since many graphics drivers on Linux are open-source, this should be possible for many graphics cards. But take note that it won't be portable--you'll need to write some separate code for each major variant of GPU you want to support.
If you have something more specific, like that you're trying to capture OpenGL commands, that might make things easier.
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I have the task to write some crypto stuff in C and make it lightweight. The idea behind making it lightweight is, that it could run on a smartcard which doesn't offer much computational power and memory. It won't come to actually running it on a smartcard and it won't be for any practical use.
However, I'm curious if I could run the program on a smartcard without major adjustments. I'm aware that I'd probably have to change something in the IO-part but let's keep that aside. And by "smartcard" I mean a regular smartcard which could be afforded by the majority of private individuals and not some fancy stuff.
To restrict the question a little more:
Could I run the program without modification if I only use 8-bit integers in my program and the architecture is >= 8-bit, aswell as stay below the memory limit?
If no, why not?
Due to their limited CPU power, SCs mostly have their own security/encryption hardware and OS. The latter for instance controls access to critical features like the interface and key storage. Also, some of them have countermeasures against typical attack scenarios like differential cryptoanalysis, etc.
There are standards available, but which to pick depends on the actual card used. There are various SCs on the market with different capabilities and demands.
It is unlikely that your program will run without major modifications.
Note that the specs are mostly only available under NDA and possibly with additional guarantees from your side. The actual level depends on the capabilities and the card vendor.
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This isn't a platform specific question - rather I'm interested in the general platform independent areas of computer science that are particularly relevant to mobile applications development.
For example, things like compression techniques, distributed synchronisation algorithims etc.. what theoretical concepts have you found relevant, useful or enabling when building mobile apps?
Human-computer interaction is an important consideration, when you consider that mobile devices have all sorts of inputs that a "normal" computer would not - such as touch screens (with multi-touch), one or more microphones, camera(s), etc...
Taken from embedded software development is the habit to handle scarce resources such as CPU load and battery life.
My 2 cents: Augmented reality, NFC (RFID)
process calculi
I don't understand why "All of computer science" isn't relevant.
(even things large large scale computing is relevant: you can't have
a small device in your hands that does really complicated stuff
on large scale unless there's a big engine someplace else).
Derecursivation (turning recursive code into an iterative loop) came handy once because some systems try to limit the default available stack size.
Pagination (how the OS splits heap memory into "page" units) is useful to understand when deciding the size of temporary buffers.
The notion of context: context-awareness and/or context-orientation
And also mobile ad-hoc network