Target reported unsupported offsets

[dirkwhoffmann]

Hi Stefan,

I did some experiments with bgdbserver and got an error message which I don’t understand. This is what I did:

• I compiled a small C program using m68k-amigaos-gcc.
• I copied the program to an ADF together with bgdbserver.
• I launched FSUAE (Kickstart 2.0) and started bgdbserver:

• On the Mac side, I startet m68k-amigaos-gdb.
• I connected to port 8080 to start a debugging session.
• The debug session terminated with the following error message:

GNU gdb (GDB) 10.0.50.211207-144216-git
...
This GDB was configured as "--host=x86_64-apple-darwin21.1.0 --target=m68k-amigaos".
...
Reading symbols from fibo.exe...
(gdb) target remote :8080
Remote debugging using :8080
warning: Target reported unsupported offsets: Text=00c21348;Data=00c23f78;Bss=00c240f8
0x00c21348 in ?? ()

Is it a bug or am I doing something fundamentally wrong?

[bebbo]

that seems still ok. what about using now:

b main
c

and then maybe

lay split

[dirkwhoffmann]

what about using...

Yes, that worked. I can step through my program. Awesome!

I've noticed that it reports a wrong contents for fibo[1], most likely because fibo is a global variable. On your website you're stating "local variables and parameters are working now".

Indeed, all local variables are reported correctly:

Background: I was trying to add a GDB server to my Amiga emulator (vAmiga) which turned out to be not so easy. At first, I canceled the project, but since I don't like failure, I am thinking of giving it another try. By using netcat I should be able to display the packages that are exchanged by m68k-amigaos-gdb on the Mac side and bgdbserver on the FS-UAE side. If I manage to mimic what your bgdserver is doing, it should be possible to connect m68k-amigaos-gdb directly to vAmiga.

[bebbo]

AFAIK: there are versions of fs-uae and winuae providing gdb support.

[dirkwhoffmann]

AFAIK: there are versions of fs-uae and winuae providing gdb support.

Yes. The original plan was to make vAmiga compatible with the VSC plugin written by @prb28 in a similar way to what has already been achieved with UAE and FS-UAE. The project progress is documented in this thread: https://github.com/dirkwhoffmann/vAmiga/issues/618

At some point I put the project on hold. I stumbled over so many obstacles that I got the feeling that it will cost too much time at the end. However, I am still hoping that the integration will be achieved eventually. Right now, I think it's best to move forward in small steps. For me, the most promising step at the moment seems to be to make vAmiga mimic what your bgdbserver is doing.

[dirkwhoffmann]

Quick question: This is part of my recorded log (exchanged between m68k-amigaos-gdband bgdbserver):

+$c#63
+$T051:00c21472;#22
+$p11#d2
+$00c21472#c3

I understand that in package +$T051:xxxxxxxx;#yy, xxxxxxxx is the program counter, 05 is SIGTRAP, and 1 is the register number. Shouldn't it be 11 (decimal 17) instead of 1? I guess you're transferring the PC to avoid the p11 request that is coming immediately afterwards.

BTW, a lot of conversation with vAmiga is already working. I can connect your m68-amigaos-gdb directly to my emulator and step through my test program (the values of variables are still wrong yet):

Emulator side: