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Read-Only
Author
erik malund
Posted
15-Aug-2001 22:25 GMT
Toolset
C51
New! 3 little brown squares
I have been using the Keil tools for a long time and decided to try uVision for the first time and now have 3 projects. 2 hum along just fine, but in the 3rd I get "warning L1 unresolved external symbol" and "Warning L2 refrence made to unresolved external" both followed by "SYMBOL: WRITETOFLASH" I have cut the module containing the reference to the bare minimum:

PUBLIC WriteToFlash
FLASHIT SEGMENT CODE
RSEG FLASHIT
WriteToFlash:
ret
end

In this project the 3 little brown squares I see next to "target 1" on all 3 projects appear next to the name of the above file.

What is wrong ?

Erik
Read-Only
Author
erik malund
Posted
16-Aug-2001 14:36 GMT
Toolset
C51
New! RE: brown squares gone, still problem
I deleted the file from the project and added it back, the brown squares are now gone, but I still get the error.

Erik
Read-Only
Author
erik malund
Posted
16-Aug-2001 15:17 GMT
Toolset
C51
New! RE: brown squares gone, still problem
is the problem related to the call from the "C" code :
bit CdataWrite(char xdata * loc, unsigned char dat);
Read-Only
Author
erik malund
Posted
16-Aug-2001 15:44 GMT
Toolset
C51
New! RE: what is the problem
I removed the parametres from the function call in the "C" source i.e. void CdataWrite(void) and now the error is gone. It can not be true that you can not pass values from "C" to an assembler function, what have I missed?

Erik
Read-Only
Author
erik malund
Posted
16-Aug-2001 16:27 GMT
Toolset
C51
New! RE: This thing is stupid
Found the reason: when Keil "C" calls an external function it will call it by its name if there are no parmetres attached; however if there are parametres attached it is called by _name.

Is this done just to confuse poor souls like me or is there madness to the reason?

Erik
Read-Only
Author
Jon Ward
Posted
16-Aug-2001 19:01 GMT
Toolset
C51
New! RE: This thing is stupid
The _ in front of the function name indicates that the arguments are passed in registers.

Refer to the section titled, "Interfacing C Programs to Assembler" in the C51 Compiler User's Guide. The _ is explained there under Function Parameters.

This is also described in the following knowledgebase article:

http://www.keil.com/support/docs/712.htm

Jon

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