Hi guys,
I am currently using the evaluation software C51 tool kit to compile my c code into machine code. Apparently, this version of software has a limitation of 2k of object code. At first I thought that will be a .hex file, but then after I manage to squeeze my code size to a size that the version is able to compile (before that it always comes out with a message saying I exceed the 2k limit), I realise that my .hex file is around 8kB, so it is clear that that is not the one. I would like to ask what does it mean by object code? Which will be the file that cannot exceed 2k of size? Shouldn't be the one with .obj as well I think, as those exceed 2k as well.
Thanks guys.
Regards, Siang
An object file constains a lot of data besides the "machine code" you talk about. The size of the object files will also be affected by debug information. Obviously it wouldn't be good if max size would be affected by the length of your variable names or function names.
A hex file is just a more verbose representation of a program, where each byte in the processor is represented by two bytes in the hex file. The hex file also contains checksum information, address information etc. Oviously it isn't meaningful to use the size of the hex file.
The only meaningful way is to count number of bytes inside the processor after a program is loaded.
Actually, the compiler does this for you and gives you the numbers at the end of the compilation.
Or you check the list files.
what is my program size then?
Program Size: Code=27636 RO-data=676 RW-data=496 ZI-data=27516
the binary on the hard disk without debug information is 34,164 bytes long.
Note that a binary file does not contain any address information. If the code has holes, then the binary file must fill these holes with 0x00 or 0xff, which means that a binary file may be bigger than what is expected from the build log output.
Does your code contain both a boot loader and an application? It seems like the binary file has filled a gap between two code blocks to become as large as it is.
Program Size: Code=27636 RO-data=676 RW-data=496 ZI-data=27516<p>
That doesn't look like the output from C51, but rather like that of the ARM compiler.