Hello, I written simple c program mention below by selecting the lpc2148 chip but not include its startup file in the project. when i run it will go in infinite loop. I also put the break point but i think its not coming to that execution line. Is it necessary to include startup file? void main() { int a=2,b=3,c; c= a+b; }
but not include its startup file in the project.
That makes less of a difference than you think. The linker will insist on having some startup file. If you refuse to put one in the project, it'll still pick one from the library. Go figure.
so how do you stop it gettnig the library?
Why the great debate to a simple problem? Just add the startup file to your project and compile it and, guess what? your code will startup. Why are you trying so hard to avoid using the startup file. It is required to setup vectors, stack, heap, and initialise data etc. In theory you could locate your main() at the processor's start address but then you would still end up having to do what the startup files does at the beginning of your main() function.
Just use the startup file and stop wasting your time trying to avoid it!
can i write my own start up codes and librarys?
Yes. But why would you?
Why the great debate to a simple problem?
I guess you don't like schools or knowledge. Why understand things when you can just follow a magic recipe? Problem is, you need to understand things to be able to take later steps and be able to deduce where these steps will lead you.
In the end, a problem is only simple if you already know the answer - or have failed to see the real problem that needs to be solved.
Per, you guessed wrong!
The question asked was "Is it necessary to include startup file?" and the simple answer is yes because of the need to set up stack, heap, vars etc. It didn't require you to show off your superior knowledge and confuse this beginner even more.
Also this forum is meant to be for Keil/ARM related issues so the answer to the newbie's question is "yes, you need to use the startup file - go and read a decent 'C' book or visit a 'C' forum if you want to know why startup code is required for processors".
This forum would be more useful if all the 'C' questions were blocked and the posts were limited to Keil/ARM issuess.
There is a description of the start up file in the manuals. Here's the one for the 8051.
http://www.keil.com/support/man/docs/c251/c251_ap_startup.htm
can i write my own start up codes
Yes and no. Yes because the tools do indeed allow it, and no because if you had to ask, that pretty much proves you don't have what it takes to do it.
and librarys?
Yes. But it might still be rather spectacularly unwise to actually do so, depending on which libraries you're talking about.
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