Compile C++ files For Firmware?

[edisn]

Ok, i am stil trying to use NXTGCC, ...
But here is a problem which i encounterd on another part:

I compile using an Arm elf compiler, in the eclipse environment.
The compilation from .c/.cpp files to .o works fine.
But the linkung step (generate .elf file) everytime says that it dont find the function i heve implementet in the .cpp file.
(the .cpp file schould be in the objectlist and the .h file of it is included in the C file which schould call it.)
(The .cpp file just contains a single dinction: void Function_CPP(){} so it is as simple as it could be, ...)

PS: is there a method to use the normal compiler from IAR to create a Firmware which could be downloeded
via USB? (I dont have anny divice which are neded to flaish directly, so i have to use the NXT-USB bootloader, ...)

[edisn]

OK, i have found how to compile a c++ file:
I just neded to change the Headerfile to:
#ifdef __cplusplus
extern "C"
{
#endif
void function(void);
#ifdef __cplusplus
}
#endif

but now I am searching for a way to use "virtual" functions in a class.
(normal functions work fine, but i havent testet inhariances jet.)
A text i have found says something about "interwork" option, but i cant get the correct results.

[edisn]

I have found a way to use classes with virtual finctions using NXTGCC:
0) Dont forget to change the Legodownloaddir.
1) Write .cpp and .h using the clases intern, and linket to the outside by a function to be called.
The hesder must include C-linkage like deskribed in my last post:
#ifdef __cplusplus
extern "C"
{
#endif
void function(void);
#ifdef __cplusplus
}
#endif
2) Add the File to the Makefile:
CPPSRC += $(SRCDIR)/__OP_CPP.cpp // or CPPSRCARM += $(SRCDIR)/__OP_CPP.cpp
3) Change the linker from (CC) to the (CPP) line (just change which line is a comment.)
4) In syscalls.c (subfolder nxtgcc) delete the isatty function, becaus the cpp linker already knows a definition of it.

I am stil searching on information on:
> How to do Debugging on the NXT (nxtgcc using Fantom)
> If a can download a firmware from the IAR-chain.
(It schould be possible using the Fantom from nxtgcc or the version providet by Lego, but i dont get how to configure it correctly)

[timpattinson]

Can't you just solder a debugging header to the NXT mainboard ??
-Tim

[edisn]

The Most interesting point at the time is:
>If someone can download a firmware from the IAR-chain (Downloaded fropm IAR-Webside, Lego-Version for free!).

But i think i Will start a new Thread on this!
(With a more Apropriate name)

[tcwan]

I am stil searching on information on:
> How to do Debugging on the NXT (nxtgcc using Fantom)
> If a can download a firmware from the IAR-chain.
(It schould be possible using the Fantom from nxtgcc or the version providet by Lego, but i dont get how to configure it correctly)

nxtgcc currently doesn't have the means to debug code executing directly on the NXT yet.
I'm working on a NXT-based instruction level debugger for the NXT Improved Firmware (which should be similar to the nxtgcc firmware) here: http://git.ni.fr.eu.org/?p=tcwan/nxt-fi ... ;a=summary. (People interested to try it should use commit 953c08633b8d04899c53bc4618c4d50279b27cbd which is what I've used to generate the GDB session trace below -- this is considered as Alpha quality software, so caveat emptor).

There are two parts, one which is built into the modified NXT firmware, and the other is a GDB remote protocol server (nxt-gdb-server.py) which runs on the PC to interface with the GDB debugger. nxt-gdb-server.py depends on nxt-python and associated dependencies (pyusb, libusb). I presume that Eclipse would talk to the GDB server using the GDB remote protocol, but I haven't looked into this yet.

It is still not done yet, but last week I've managed to successfully initiate a gdb exchange with the NXT connected via USB. It is technically possible to get it to work over Bluetooth, but currently the NXT debugger sends its output via USB explicitly. Using the debugger, it would be possible to halt execution of the NXT firmware (and user programs), and examine the contents of registers and memory locations, and continue execution of the user program.

Code: Select all

(gdb) target remote localhost:2828
Remote debugging using localhost:2828
0x001001de in cCommHandleDebug ()
(gdb) info reg
r0             0x0	0
r1             0x201dbe	2104766
r2             0x0	0
r3             0x61	97
r4             0x20fefc	2162428
r5             0x20ad89	2141577
r6             0x20adcd	2141645
r7             0x1e	30
r8             0x0	0
r9             0x0	0
r10            0x0	0
r11            0x40000	262144
r12            0xfffb0054	4294639700
sp             0x20febc	0x20febc
lr             0x1001d7	1049047
pc             0x1001de	0x1001de <cCommHandleDebug+14>
fps            0x0	0
cpsr           0x80000033	2147483699
(gdb) x /16b &__debugger_stack_bottom__
0x201b90:	-32	1	16	0	51	0	0	-128
0x201b98:	0	0	0	0	-66	29	32	0
(gdb) cont
Continuing.

Eventually it'll have Assembly Language instruction stepping features for RAM-based programs, but that is not so useful for the NXT firmware since NBC programs execute from Flash. The RAM-based instruction-stepping feature is intended for programs written using NxOS (bare metal programs) .

I guess to debug NBC programs there should be another module on the Host PC side which can convert NBC variable locations into physical address locations. However, I'm not familiar with NBC or the NXT firmware in detail, so if someone is interested in picking this up, it'd be great.

My current issue is the USB communication between the NXT and the PC is not very reliable. I'm testing it using a Fedora 14 VM, but the USB connection tends to lock up since the libusb 0.12.x recv() calls are blocking calls which do not time out. So the GDB server to NXT connection tends to get stuck and I need to restart the GDB server. Nicolas Schodet is trying to write a Python wrapper for the Fantom Drivers so that it would be possible to use nxt-python on the Mac (hopefully Windows as well), which will mean that nxt-gdb-server.py can run on Mac (or Windows) directly. [libusb 0.12.x / 1.0.8 does not work on Mac OSX or Windows to connect to the NXT when I tried to install and use it].