Interrupt vector issues ( cant figure it out!)

Check your map file to see if GPI_ISR shows up at all. Your executable is cancpp.axf - are you compiling as C++ code? In that case the GPI_ISR function name maybe mangled and would show up as something other than GPI_ISR in the linker output.

Andrew

I am using C++.

Using the

 IMPORT  GPI_ISR [WEAK]

syntax it will build but wont go to the function. If I remove the [WEAK] syntax, it wont build and says:

cancpp.axf: Error: L6218E: Undefined symbol GPI_ISR (referred from startup.o).

This is what I copied from the MAP file, it shows GPI_ISR as an undefined Weak Reference:

  BuildAttributes$$THM_ISAv4$P$D$K$B$S$PE$A:L22UL41UL21$X:L11$S22US41US21$IEEE1$IW$USESV6$~STKCKD$USESV7$~SHL$OTIME$ROPI$IEEEJ$EBA8$UX$STANDARDLIB$REQ8$PRES8$EABIv2 0x00000000   Number         0  anon$$obj.o ABSOLUTE
    __ARM_use_no_argv                        0x00000000   Number         0  main.o ABSOLUTE
    __Vectors                                0x00000000   Data           0  startup.o(RESET)
    __dso_handle                             0x00000000   Number         0  startup.o(RESET)
    _printf_flags                            0x00000000   Number         0  printf_stubs.o ABSOLUTE
    _printf_return_value                     0x00000000   Number         0  printf_stubs.o ABSOLUTE
    _printf_sizespec                         0x00000000   Number         0  printf_stubs.o ABSOLUTE
    _printf_widthprec                        0x00000000   Number         0  printf_stubs.o ABSOLUTE
    GPI_ISR                                   - Undefined Weak Reference
    SHT$$ARM_EXIDX$$Base                      - Undefined Reference
    SHT$$ARM_EXIDX$$Limit                     - Undefined Reference

Thanks for the help.

And have you tried to tell your nice C++ compiler that you want it to create your function using the standard C naming convention?

No I have not, I am new to Keil. How would I go about doing this?
Pleas send me a link or some info.

Thank you.

Doesn't matter if you are new to Keil.

It's a question about what you know about C++, the programming language.

How do you think C++, with name mangling of all external references, can link with C functions like printf(), atoi() etc that do not have their names name mangled?

Enlighten me.

try declaring your GPI_ISR as

extern "C" GPI_ISR();

This should generate a standard C naming convention symbol which then is linked to the startup file.

Andrew

This is my first C++ project on a non windows machine so I am still kind of lost.

Thanks for that Andrew .

It's the same with Keil as with Windows as with OS/2 as with Linux.

Whenever a C++ program needs to access a C function, it has to know that the C function that gets linked in is "C"

And to let a C program reach a C++ function, the C++ function must specify that it should use "C" naming and calling conventions.

The reason for the name mangling in C++ is to allow polymorphic functions, where the same function name can be used multiple times but with different sets of argument types. And to get type-safe linking - the linker will only be able to match the symbol names when caller and implementation expects the same set of data types.

Since C does not have name mangling, C++ is required to have a standard method to declare when name mangling can not be used. So a good C++ book will cover this, and lots of other useful details.

Thanks Westermark.
Although I have read many C++ books ( I honestly don't recall seeing that in them), I have never had the need to mix C++ and C functions directly, until now. The libraries always had the extern "C" in them, and I never paid attention to it much. But thanks for taking the time to explain.