| ??? 11/02/07 20:21 Read: times |
#146529 - Is this even feasible Responding to: ???'s previous message |
John Stockhausen said:
We're considering porting freemodbus... You mean http://www.freemodbus.org ? Is this even feasible given the HW constraints? They seem to think so: freemodbus.org said:
The hardware requirements are minimal - Any reasonable microcontroller with a serial interface, at least some RAM to hold the modbus frames should suffice. And they show figures for an AVR, which don't look excessive for a C8051F41x: http://www.freemodbus.org/index.php?idx=2 ...after removing some unused code ... changing some 16-bit counters to 8-bit, and selecting "Large: variables in XDATA" in Keil, we still get "UNRESOLVED EXTERNAL SYMBOL" warnings for a good number of functions in the freemodbus code. What happens if you don't mess with the code? Does it build "as-is" ? Are these the only warnings you get, or are they preceded by any others? Do I have to do something special to tell the compiler to look for these functions which I think may have been moved to XDATA? As Erik says, no functions can be in XDATA - the 8051 architecture can only ever executable instructions from CODE space! |
| Topic | Author | Date |
| Porting FreeModbus | 01/01/70 00:00 | |
| they are not | 01/01/70 00:00 | |
| Is this even feasible | 01/01/70 00:00 | |
| compiler warnings | 01/01/70 00:00 | |
| The table and function pointer | 01/01/70 00:00 | |
More on function pointers in Keil C51 | 01/01/70 00:00 | |
| more porting to do | 01/01/70 00:00 | |
| You mean linker | 01/01/70 00:00 |