Set function to specific address in PIC18F with the HI-TECH C compiler

Question

I want to put a function in an specific address of memory like PIC C Compiler (#org). I'm using MPLAB X, HI-TECH compiler and PIC18F4550.

In PIC C compiler:

#org 0x1000, 0x2000
void MyFunction()
{
}
//In other part of code I'll use: asm("goto 0x1000");

How to do this in MPLAB X with the HI-TECH compiler?

• Majenko: I don't understand why you'd need to. You can reference the symbol MyFunction from assembly (maybe as _MyFunction depending on compiler).
• Majenko: Also, you should never ever ever "goto" a function, or "goto" anywhere outside your current function.

Answer 1

IIRC, you can set a function to an absolute address by using the "@" qualifier:

void MyFunction() @ 0x2A0
{
 ...
}

So the function MyFunction will be placed at address 0x2A0 in Program Memory.

• 788498: Thanks @m.Alin, I worked. I'd like to ask you how to use int address = 0x20; **asm("goto "___mktstr(addr));** but If I use asm("goto "___mktstr(0x20)); works. I want to use goto to go a specific address using addr variable, perhaps there is another option like goto_address(addr) in pic CCS compiler. Thank you.
• m.Alin: The ___mktstr(x) macro stringifies its argument. ___mktstr(0x20) will return the string "0x20", but ___mktstr(addr) will return the string "addr".
• 788498: Thanks, but I still couldn't find a way to GO to a variable address. It looks like asm() argument must be char constant. Is there another solution to jump to an address using goto?
• m.Alin: @jaspher I'm not experienced in assembly. You should ask a new question regarding that.

Answer 2

use the linker command file to set the address of .text portion of MyFunction

• Null: This doesn't seem to answer the question. Please add further explanation.