Problems using Insight/GDB for Coldfire

Problems using Insight/GDB for Coldfire

["Dörr, Dirk"]

[-- Attachment #1: Type: text/plain, Size: 2394 bytes --]

Hi!

I am currently working on a ucLinux project for a MCF5272 and I have some trouble using the Insight/GDB debugger with bdm.

I am using the binary version from sourceforge.net.

Before starting with ucLinux I build a small test application that runs in the SDRAM at 0x20000 (MCF5272C3 eval board).

Debugging with gdb works fine:

> m68k-bdm-elf-gdb tstart.elf
(gdb) load
(gdb) set $pc=0x20000
(gdb)
list
(gdb) list
1       int _main()
2       {
3       int i;
4       int a=1;
5       for (i=0;i<10;i++)
6               {
7               a*=(i+1);
8               }
9       for(;;);        return 0;
10      }
(gdb) break 5
(gdb) c
Continuing.

Breakpoint 1, _main () at main.c:5
5       for (i=0;i<10;i++)
1: x/i $pc  0x20042 <_main+10>: clrl %fp@(-4)

In the working directory is a .gdbinit file that configures the sdram controller and sets the target to /dev/bdmcf0 .

But with Insight I have the folling problem:

I start with

m68k-bdm-elf-insight

I can see memory and change it. I can see registers but can't change them.

File->Open

tstart.elf

Now I can see the code of the application at 0x20000 

but the memory below (0x1fff0)  and above (0x20080) are marked N/A.

Then I choose Run->Download

The download dialog shows: 134 bytes (118 .text and 16 .data). 

m68k-elf-objdump -x tstart.elf:


tstart.elf:     file format elf32-m68k
tstart.elf
architecture: m68k, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x00020000

Program Header:
    LOAD off    0x00002000 vaddr 0x00020000 paddr 0x00020000 align 2**13
         filesz 0x00000088 memsz 0x00000088 flags rwx
private flags = 0:

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .text         00000076  00020000  00020000  00002000  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  1 .data         00000010  00020078  00020078  00002078  2**2
                  CONTENTS, ALLOC, LOAD, DATA
 

Seems ok.

But now at 0x20000 there is :

0xcebc0000 0xffff2f07 0x48780010 0x61002226

instead of 

0x4e7146fc 0x27002e7c 0x00000000 0x4e7bf801

and I can't change the memory. 

What am I doing wrong? 

BTW: The buttons for step, next ... are greyed out.

Thanks
-- 

Dirk Dörr

P. S.:

I posted this message to:

bdm-devel@lists.sourceforge.net
uclinux-dev@uclinux.org

[-- Attachment #2: start.tar.gz --]
[-- Type: application/x-gzip, Size: 5297 bytes --]

Re: Problems using Insight/GDB for Coldfire

[Keith Seitz]

On Wed, 2003-09-17 at 01:22, "Dörr, Dirk" wrote:
> I am using the binary version from sourceforge.net.

Can you give me a URI?

> Debugging with gdb works fine:
> 
> > m68k-bdm-elf-gdb tstart.elf
> (gdb) load
> (gdb) set $pc=0x20000
> (gdb)
> list
> (gdb) list
> 1       int _main()
> 2       {
> 3       int i;
> 4       int a=1;
> 5       for (i=0;i<10;i++)
> 6               {
> 7               a*=(i+1);
> 8               }
> 9       for(;;);        return 0;
> 10      }
> (gdb) break 5
> (gdb) c
> Continuing.
> 
> Breakpoint 1, _main () at main.c:5
> 5       for (i=0;i<10;i++)
> 1: x/i $pc  0x20042 <_main+10>: clrl %fp@(-4)
> 
> In the working directory is a .gdbinit file that configures the sdram controller and sets the target to /dev/bdmcf0 .

In the example, I don't see a target command. Please either send (to the
list) the .gdbinit you are using OR run a gdb session IN LINE (i.e,.
"file foo.elf", "target BLAH", "load", "break bar", "continue", ...).

> But with Insight I have the folling problem:
> 
> I start with
> 
> m68k-bdm-elf-insight
> 
> I can see memory and change it. I can see registers but can't change them.

Probably a bug -- you haven't specified a target yet... You shouldn't be
able to change memory or registers.


> Then I choose Run->Download
>
> The download dialog shows: 134 bytes (118 .text and 16 .data). 

Well, it seems that you have attached to a target (probably in
.gdbinit). I'm pretty sure this will confuse Insight enormously,
especially if the target code was written by anyone with no Insight
experience. This issue has come up countless times before.

> But now at 0x20000 there is :
> 
> 0xcebc0000 0xffff2f07 0x48780010 0x61002226
> 
> instead of 
> 
> 0x4e7146fc 0x27002e7c 0x00000000 0x4e7bf801
> 
> and I can't change the memory. 

Well, Insight is just a UI (and a ton of glue code between the
command-line gdb and the Tcl interpreter that runs the UI). The actual
loading is handled by gdb. In fact, with only a few minor differences,
selecting "Run->Download" is EXACTLY the same as typing "load" at the
console.

> What am I doing wrong? 

Again, if I were you, I would NOT put anything in the .gdbinit file
which would alter target state (i.e., no "target" command, no register
setting, no memory altering, etc.). Insight can still read gdb script
files (File->Source...), so if you wanted to do stuff after attaching to
the target, then I would put those things into a script file and source
it in manually.

The problem is that gdb controls when the .gdbinit is read -- it may be
read by gdb before Insight is even initialized. Thus, Insight gets no
notification that anything has happened.

Try running insight WITHOUT the .gdbinit file in place (just rename it
temporarily). Use the following commands to "run" your exe: File->Open,
set a break, click "Run" button (a target selection dialog should show,
allowing you to configure the target). You should not need to anything
more (well, most of the time, at least).

> BTW: The buttons for step, next ... are greyed out.

This is an indication that Insight doesn't know that you've attached to
a target. This could be indicative of a bug in the target code, too, but
we'll diagnose that later. First things first: I need to know a lot more
about your target.

Keith

RE: Problems using Insight/GDB for Coldfire

["Dörr, Dirk"]

Hi!

On Wed, 2003-09-17 at 16:35, Keith Seitz wrote: (@ insight@sources.redhat.com list):

> Ok, I would just whack everything below the "target" command from your
> .gdbinit and save it into another file. You can use the "Command to run
> after attaching to target" thingy in the target selection to source in
> the other script. (So, save everything below the "target" command into,
> e.g., ~/setup-bdm; then open a target selection dialog (File->Target
> Settings...), select the BDM target, fold down the "More Options" thingy
> and type in the "Command to run after attaching" something like "source
> ~/setup-bdm

Executing the init sequence after starting insight improves the situation. 

But there are still problems like losing focus in source, 
register changes are not displayed ...

I get the impression that there is a general problem with bdm and gdb...

I contacted Thomas Elter from embeddedtools.net (they sell the microcross 
gcc based cross-tools) and got this answer:


> [... Snip ...] 
> It appears that the main problem in your development environment is the P&E Micro 
> connection device. It turns out that the P&E Micro connection device, is not compatible with any GNU
> tool suite release from any vendor. The P&E Micro connection device will
> download the object load module to the target, but will not support any
> debug activities with a GNU Debugger like GDB. Microcross made an attempt to
>work with them to find a solution, but they were not interested.

He offers a Abatron BDI2000 and an other BDM interface from Cybertec

Ok. BDI2000 uses tcp/ip remote debugging. But the bdm inteface from cybertec? 
There should be no big difference between this one and the P&E device? 
Both using parallel port.

So my question: 

Is anybody else using the P&E BDM Interface for Coldfire with Insight/gdb
or can confess the compatibility problems of P&E? 



Bye

-- 

Dirk Dörr

Sorry for crossposting!