I recently started reading Charles Petzold book titled Code, which so far covers exactly the kinds of things I assume you are curious about. But I have not gotten all the way through so thumb through the book first before buying/borrowing. This is my relatively short answer, not Petzolds…and hopefully in line with what you … Read more
When an exception occurs there will be time overhead which depends on how you implement your exception handling. But, being anecdotal, the severity of an event that should cause an exception will take just as much time to handle using any other method. Why not use the highly supported language based method of dealing with … Read more
At Galois we use Haskell for two things: Soft real time (OS device layers, networking), where 1-5 ms response times are plausible. GHC generates fast code, and has plenty of support for tuning the garbage collector and scheduler to get the right timings. for true real time systems EDSLs are used to generate code for … Read more
Since you say “embedded system” and “small and fast” and “integrate nicely” I would say you are correct that Lua is the number one if not the only choice. But I no longer agree that the programming language has “quirky corners”. Firstly, the book Programming in Lua is simply splendid, one of the best books … Read more
Linux is a general-purpose OS (GPOS); its application to embedded systems is usually motivated by the availability of device support, file-systems, network connectivity, and UI support. All these things can be available in an RTOS, but often with less broad support, or at additional cost or integration effort. Many RTOS are not full OS in … Read more
Pretty much. When you redirect the stdout of the program to /dev/null, any call to printf(3) will still evaluate all the arguments, and the string formatting process will still take place before calling write(2), which writes the full formatted string to the standard output of the process. It’s at the kernel level that the data … Read more
I would use HDLC. I have had good luck with it in the past. I would for a point to point serial just use the Asynchronous framing and forget about all of the other control stuff as it would probably be overkill. In addition to using HDLC for the framing of the packet. I format … Read more
Embedded software may have come a long way in the last 10 years but we generally did the following: for algorithms that didn’t depend on the target hardware, we simply had unit tests that were built and tested on a non-embedded platform. for stuff that did require the hardware, unit tests were conditionally compiled into … Read more
You are attempting to link your project in such a way that the target of a relative addressing scheme is further away than can be supported with the 32-bit displacement of the chosen relative addressing mode. This could be because the current project is larger, because it is linking object files in a different order, … Read more
A homebrew Forth runtime can be implemented in very little memory indeed. I know someone who made one on a Cosmac in the 1970s. The core runtime was just 30 bytes.