Is there any way to declare a symbolic constant as 'an external number' in Keil C51 source code so that the compiler generates object file using instructions with # symbol prefix (e.g. mov r0,#symbol) and therefore the value of this symbol can be supplied on the linker level (from another obj file, where the symbol is given a value and declared as public) ? (Including file with #defines into the source code does not solve the issue - symbols must be defined at the compile time.) Note: in assembler it is easy ... file1.a51 : (file1.obj defines particular values of needed constants for a concrete project)
... public SYMBOL SYMBOL equ 5 ...
... extrn number (SYMBOL) ... mov a,#SYMBOL ...
Sorry, I was replying to your orignal question of generating a "mov r0,#symbol" where the symbol is supplied on the linker level. I just assumed you had a assembly program that generated these constants. I know of no standard "C" way of doing what you ask. The only way I know is ugly. You have to export the constant as an address. The following will export the constant 0x1234.
char xdata symbol _at_ 0x1234;
char xdata symbol[] _at_ 0x1234;