Post by thread:[PIC] MCC18 Linker Error

I'm getting this error when compiling a C program with Microchip C18: MPLINK 4.04, Linker Copyright (c) 2006 Microchip Technology Inc. Error - could not find definition of symbol 'GoTimersIsr' in file 'C:\ProductDesigns\Iq512\061116\isr.o'. Errors : 1 The fact that it is a linker error instead of a compile error makes me think it is not a header file problem. isr.c is calling GoTimersIsr which is defined in GoTimers.asm. Some of that code is: MyCode code GoTimersIsr banksel FadeOutScale ; set bank select for ram used here btfsc FadeDelay+1,7 ; skip next if FadeDelay positive ... more code... global GoTimersIsr end The fact that the linker is not finding it makes me think I'm missing the global command... But there it is! So, ideas? I'm getting tired of hitting F10 over and over again and getting the same error! THANKS! Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available!

Have you tried to put the "global" at the start (before the function/label) of GoTimers.asm ? Not saying that that's the error, but that's what I would try... :-) Jan-Erik. Harold Hallikainen wrote : {Quote hidden}> I'm getting this error when compiling a C program with Microchip C18: > > MPLINK 4.04, Linker > Copyright (c) 2006 Microchip Technology Inc. > Error - could not find definition of symbol 'GoTimersIsr' in file > 'C:\ProductDesigns\Iq512\061116\isr.o'. > Errors : 1 > > > The fact that it is a linker error instead of a compile error makes me > think it is not a header file problem. isr.c is calling GoTimersIsr which > is defined in GoTimers.asm. Some of that code is: > > > MyCode code > > GoTimersIsr > banksel FadeOutScale ; set bank select for ram used here > btfsc FadeDelay+1,7 ; skip next if FadeDelay positive > > ... more code... > > > global GoTimersIsr > > end > > > The fact that the linker is not finding it makes me think I'm missing the > global command... But there it is! > > So, ideas? I'm getting tired of hitting F10 over and over again and > getting the same error! > > THANKS! > > Harold > >

Jan-Erik Söderholm wrote: > Have you tried to put the "global" at the start > (before the function/label) of GoTimers.asm ? > > Not saying that that's the error, but that's what > I would try... :-) > > Jan-Erik. > And if that doesn't work, try decorating the GoTimersIsr label with an underscore, viz: _GoTimersIsr Most other C compilers (that I've come across) decorate functions with an underscore. I don't believe that C18 is any different in this respect. So you have to do all the work in your assembly module to conform to the environment that the C compiler expects. Additionally, if you're calling this function from C, then I'd also check the C compilers output to see what function prologue and epilogue are generated in addition to the code that gets generated because of the C you've written (i.e. the implementation of the C18's calling convention). Your initial banksel statement may be enough, but check, just to make sure, you may be required to restore the bank originally used by the C compiler when you got called before you exit the routine. Your Mileage May Vary; my main experience is C on Microcomputers (where prologue and epilogue code tends towards the baroque), although I've had a few minor successes with C18 on PICs in the last couple of years. But I've never tried to interface assembly and C on a PIC. Regards Dave Jolley.

Thanks for the responses. Turns out that I had the same source file name (with different extensions) for the C and ASM code that deals with this portion of the project. So, I believe the object files ended up with the same names, and one overwrote the other. I changed the asm file to GoTimersAsm.asm and all is well. Thanks! Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available!