? Colin, Would you please explain what steps do we need to use before delivering a embedded code when we use some library from device manufacturer to get free any licence or paying extra money while they didn't guarantee for that library but they mentioned it is under their licence?
sometimes Peripheral devices are not generally software friendly and it took much time to be synchronzied with embedded platforms and also there is not any guidline to implement a proper solution and we should test and change software code to get the required result
@samsul: ARM has done a decent job at making libraries available. They have standardized on CMSIS and most vendors of ARM parts that I know of have made these libraries avaiable. However, they're still not always the easiest things to use. Complicated hardware makes for complicated software -- even (or especially) for predefined libraries.
@ Charles, I'm listening to the audio post, and curiously, the audio levels are fine in the recorded version, equal to the sign on. It's only in the stream that the presentor's levels are soft. Hope that is helpful to your team.
I think the reentrancy code is really talking about the synchronization in the code. That is the reason we need the lock() and unlock() function to avoid the race condition for the critical data. Once the code run into the lock() and unlock(), it will make the code in sequence.
@lazar.ivanovic: the overloaded char operator is used whenever you convert from an nvramchar type to a "normal" char - an assignment as I showed is a simple example. Really, on slide 9, I shjould have written:
We are now in year 2014.... times moving fast. Should it not be the responsibility of the manufacturers to come out with libraries for their peripherals? So, programmers just apply them in his/her apps. At least the libraries up to certain point to ease programmer's life
When I design a peripheral I try to make it as software friendyl as possible but sometimes the customer will demand that a few pennies be saved on teh hardware not realizing that savings will be wiped out by the additonal sofware development cost.
The stanard meaning of re-entrant is a program that can call itself, ie n! = n*((n-1)!). Your use here is normally called serialization. Your description of what you wanted to do was very clear, but the terminology might cause some confusion when communicating with someone used to the standard definition.
@mcurry: I did not use the string class for 2 reasons. First when this code was first written, this class was not in widespread use. Second, I wanted as much of this code to be "C programmer friendly" as possible
? @Colin: i noticed that the checksum was located before the signature field. Why was that? it would seem prudent to include the signature data field in the checksum by putting the checksum after all written data, that way you would know that the written signature was what you thought it was.
?@Are peripheral devices generally "software friendly"? I tend to believe that low level designers have fun in trying to "save the world" and solve problems long term. However, some companies may put too much effort in sticking to the release dates and other commercial pressures and continue for decades to wirte buggy code even at the lowest level.
?Colin - What about using a separate nvram class to hold the baseaddr and size and to do the initialization? You could then pass the nvram object to the nvramchar constructors to set up the individual variables.
? I seem to remember, from my coursework on compilers, that function arguments tend to end up on the stack and we have discussed allocated memory ends up on the heap. We discussed fragmentation as a problem with OO design since new calls malloc which is a heap operation and then free can fragment memory. The method of addressing that is with binned heap segments which has some obvious memory inefficiences. Isn't use of the stack more memory efficient? It seems like the C+ alternative to C would have to be very carefully written with a conservative and thoughtful use of class variables. C naturally pushes code in that direction. Are there any design guidelines that push a C design in that same direction?
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