In http://www.keil.com/support/docs/788.htm you described how to change the putchar function. I have coppied PUTCHAR.C to the project directory, and added it to the project source files (using uVision2). As soon as I started to re-build the project, the following error occured: Build target 'Target 1' compiling SIO.C... compiling MAIN.C... compiling PUTCHAR.C... linking... *** ERROR L104: MULTIPLE PUBLIC DEFINITIONS SYMBOL: _PUTCHAR MODULE: .\output\PUTCHAR.obj (PUTCHAR) *** WARNING L16: UNCALLED SEGMENT, IGNORED FOR OVERLAY PROCESS SEGMENT: ?PR?_PUTCHAR?PUTCHAR *** ERROR L118: REFERENCE MADE TO ERRONEOUS EXTERNAL SYMBOL: _PUTCHAR MODULE: C:\KEIL\C51\LIB\C51S.LIB (PRINTF) ADDRESS: 0080H *** ERROR L118: REFERENCE MADE TO ERRONEOUS EXTERNAL SYMBOL: _PUTCHAR MODULE: C:\KEIL\C51\LIB\C51S.LIB (GETCHAR) ADDRESS: 06E2H Program Size: data=50.3 xdata=0 code=1780 Target not created Why ? Where else is putchar defined ? what can I do in order to change putchar ? Another question is where can I see the source code of printf ? Thanks, Amit.
What's in the SIO source file? Jon
The following project, http://www.keil.com/download/docs/intsio2.zip.asp with minor changes.
*** ERROR L104: MULTIPLE PUBLIC DEFINITIONS SYMBOL: _PUTCHAR means you have a in your project two 'putchar' functions. 'putchar' is already defined in main.c. So you do not need another module that defines putchar. Therefore remove the putchar.c module from your project.
linking... *** ERROR L104: MULTIPLE PUBLIC DEFINITIONS SYMBOL: _PUTCHAR MODULE: .\output\PUTCHAR.obj (PUTCHAR)
*** ERROR L104: MULTIPLE PUBLIC DEFINITIONS SYMBOL: VARIABLE_NAME MODULE: File_Name1.obj (FILE_NAME) MODULE: File_Name2.obj (FILE_NAME)
Andy, LX51 does this already. It includes a DEFINED: <symbol> information.
Did you remove the putchar and getkey functions from MAIN.C in that example? Jon
"Andy, LX51 does this already." Jolly good!
Hi, Sorry for the delay with my response. Since the error was not clear (didn't point at the relevant place in the code where the problem is), and since the code was downloaded from another place, and was not originally my code, I missed that putchar redefinition in the main. I am sure that this was the problem, but I didn't have time to verify it. My task was changed and I didn't need to use main any more (and didn't have time for it). Anyway, thanks for your kind help. Best Regards, Amit A.
But not everyone have LX. What about us ? Will it stay this way ?
Another question is where can I see the source code of printf ? This question was left unanswered. is it possible to see the source code at all ? Thanks, Amit.
Sorry, the source code is not public.
"Sorry, the source code is not public." That is to say, the source for Keil's C51 printf implementation is not public. I'm sure you can find some open-source printf implementation(s); eg, SDCC is open-source: http://sdcc.sourceforge.net/ Of course, that will not be the same as Keil's implementation; no doubt Keil have put a lot of work into optimising their C51 implementation - which is why they're not about to give it away free to all & sundry!
Just to explain, I wanted to have the source in order to debug a printf command that didn't work. this problem was solved, but at that time I wanted to perform the printf command step by step for debug purposes. Amit.
FYI, here is a list of those library functions for which source code is available: http://www.keil.com/support/man/docs/c51/c51_lib_source.htm