So I want to replace a standard function in the C51S library. Shouldn't be too hard, right? I rewrote the function (?C?LMUL to be specific) in assembly and compiled it using the A51 assembler. (processes it without complaint) The code looks like this:
; Segment Definition ?C?LMUL SEGMENT CODE ; Module Start RSEG ?C?LMUL MOV ... ... END
LIB51 DELETE C51S.LIB (?C?LMUL)
LIB51 ADD NEW_LMUL.OBJ (?C?LMUL) TO C51S.LIB >> ERR 223 CANNOT FIND MODULE
LIB51 ADD NEW_LMUL.OBJ TO C51S.LIB LIB51 LIST C51S.LIB
A segment is not a symbol, therefore you get syntax error. See: http://www.keil.com/appnotes/docs/apnt_149.asp This explains how to structure assembler files. Also you find plenty of examples under http://www.keil.com/support. As a general rule: do not modify C51 run-time libraries. Just add your modifications to an own library.
I can not say this is the cause, but on some library work I have seen the NAME pseudo-op being extremely important. Try inserting a NAME statement. Oh, i recall, if you copy a module to another name to make two slighbtly different libray functions and forget to change the NAME statement in the modified copy, all hell breaks lose with meaningless error messages and who knows what. Erik