[En-Nut-Discussion] simulate ethernut sample in avr studio

[Andreas Heinzen]

Yes, I had read the FAQ and all the documents in web I found, which
say it didn't work.

But I gave it a try and for simulate some hardware I used hapsim,
http://www.helmix.at/hapsim/

so my experiment starts with:
AVR Studio 4.12.490 (SP3)
HAPSIM V 2.07

I opened in AVR Studio a new project lcd without any auto generated files.
The project dir should be saved in the ethernut $top_appdir

The lcd.c:
#######################################
#include <compiler.h>
#include <stdio.h>
#include <dev/hd44780.h>
#include <dev/term.h>
/* Connect Definitions found in cfg/medianut.h
LCD DATA Port   = PORT D Bits 4..7
Reg. Select PIN = PORT E Bit 2
Enable PIN      = PORT E Bit 3
Read/Write PIN  = PORT E Bit 4
(see also hapsim file lcd.xml)
*/

void main(void)
{
        NutRegisterDevice(&devLcd, 0, 0);
        freopen("lcd", "w",stdout);
        printf("Hello world!\n");
}
#######################################

The external Makefile  used for compilation:
#######################################
PROJ = lcd

include ../Makedefs

CPFLAGS +=  -gdwarf-2


SRCS =  $(PROJ).c
OBJS =  $(SRCS:.c=.o)
LIBS =  $(LIBDIR)/nutinit.o -lnutos -lnutarch -lnutdev -lnutcrt $(ADDLIBS)


all: $(OBJS) $(TARG) $(DTARG) info

include ../Makerules

info:
#        avr-nm  -Sa $(DTARG)
        avr-objdump -h $(DTARG)
        avr-size -xA $(DTARG)


clean:
        -rm -f $(OBJS)
        -rm -f $(TARG)
        -rm -f $(DTARG)
        -rm -f $(PROJ).eep
        -rm -f $(PROJ).obj
        -rm -f $(PROJ).map
        -rm -f $(SRCS:.c=.lst)
        -rm -f $(SRCS:.c=.bak)
        -rm -f $(SRCS:.c=.i)
#######################################

My hapsim file shows 1 lcd-display and is conected  as discribed
in lcd.c open it in hapsim, in my simulation I also connected one
led to each Pin of PORTD and  PORTE,
to see that something happens, but the mail gets to long ;-)
.
lcd.xml:
#######################################
<?xml version="1.0"?>
<HAPSIM>
   <General>
      <Build>1793</Build>
      <Position>
         <top>326</top>
         <bottom>531</bottom>
         <left>441</left>
         <right>868</right>
      </Position>
      <StayOnTop>1</StayOnTop>
      <Target>ATmega128</Target>
   </General>
   <Views>
      <LCD>
         <Name>LCD1</Name>
         <Position>
            <top>14</top>
            <left>78</left>
         </Position>
         <DisplayConfig>
            <columns>16</columns>
            <rows>2</rows>
            <bkColor>0xc1fa9d</bkColor>
            <size>2</size>
         </DisplayConfig>
         <PortMapping>
            <DataPort>
               <Port>PORTD</Port>
               <HighNibble>bit 4..7</HighNibble>
               <LowNibble>N.C.</LowNibble>
            </DataPort>
            <EnablePin>
               <Port>PORTE</Port>
               <Bit>3</Bit>
            </EnablePin>
            <RW_Pin>
               <WriteOnly>1</WriteOnly>
               <Port>PORTE</Port>
               <Bit>3</Bit>
            </RW_Pin>
            <RS_Pin>
               <Port>PORTE</Port>
               <Bit>2</Bit>
            </RS_Pin>
         </PortMapping>
      </LCD>
   </Views>
</HAPSIM>
#######################################

What should I say, after compiling, starting the debugger, hook hapsim to
AVR Studio it works, ...
but with hundreds of warning messages about:

AVR Simulator: Uninitialized stack pointer used at ...
AVR Simulator: Stack Overflow at ...
...
AVR Simulator: Stack Underflow at ...
...

Because of these messages the simulation is unusable slow, I think it tooks
more than 10 minutes to get the "hello world!" on the hapsim display
(But it works!!!).

So I made some analyze of the resulting elf target.

And found out, by comparing with an another project, that there is an
section .debug_range missing.

Another mystery, when you look at the Makefile, you find the line 
#        avr-nm  -Sa $(DTARG)

by removing the comment the build fails with three errors and shows:
NutTimerStop
NutTimerStopAsync
nutTimerStopped
as the reason.

I also build the Nut/OS with -gdwarf-2 and it was very interesting
to debug through C-Code of the initialize process, to find out 
what is going wrong, but i didn't realy no what I'm searching for.

I hope someone here in the list with more knowledge about avr-gcc and 
what should happen to initialize correct, gets some hints through my
experiments and could fix the problem.

Sorry, about the long mail.

Andreas Henzen