Can't talk to Angel debug monitor from arm-elf-gdb

Can't talk to Angel debug monitor from arm-elf-gdb

[Dave Cleal]

Hi,

I've got an ATMEL EB40A ARM evaluation board that has ARM Angel 1.04
running in the flash, and I can talk to this fine from the
ARM-supplied AXD debugger. But I can't talk to it from arm-elf-gdb (I
have v.6.1, compiled by macgraigor.com) which is running under cygwin
on Windows 2000. arm-elf-gdb works just fine with the simulator
target.

I start up arm-elf-gdb, then do

set remotebaud 9600
target rdi com1

The second command just hangs, I can see LEDs flashing to indicate
that data is passing back and forth, but no response in gdb.

Any ideas?

- Dave

RE: Can't talk to Angel debug monitor from arm-elf-gdb

[Dave Korn]

> -----Original Message-----
> From: gdb-owner On Behalf Of Dave Cleal
> Sent: 22 October 2004 15:47

> I've got an ATMEL EB40A ARM evaluation board that has ARM Angel 1.04
> running in the flash, and I can talk to this fine from the
> ARM-supplied AXD debugger. But I can't talk to it from arm-elf-gdb (I
> have v.6.1, compiled by macgraigor.com) which is running under cygwin
> on Windows 2000. arm-elf-gdb works just fine with the simulator
> target.
> 
> I start up arm-elf-gdb, then do
> 
> set remotebaud 9600
> target rdi com1
> 
> The second command just hangs, I can see LEDs flashing to indicate
> that data is passing back and forth, but no response in gdb.
> 
> Any ideas?

  Not a great many.  Not a target I'm familiar with, nor the supplier.  But "set
debug remote 1" should allow you to see what's actually going back and forth,
which might give some clues...

    cheers, 
      DaveK
-- 
Can't think of a witty .sigline today....

Re: Can't talk to Angel debug monitor from arm-elf-gdb

[Dave Cleal]

(talking to myself)

Eventually got around this by re-flashing to replace Angel with
the Redboot monitor. arm-elf-gdb talks to that just fine as a remote
target.

I do have a remaining problem with my toolchain, which is that
ideally, I'd like to develop in Eclipse. Eclipse won't interact nicely
with arm-elf-gdb running a remote target. I'm not sure whether this is
Eclipse sending the wrong commands, or arm-elf-gdb responding weirdly.
Just before I start messing with Eclipse, has anyone got experience of
this kind of set up (eclipse -> arm-elf-gdb -> remote target)?

- Dave

> Hi,

> I've got an ATMEL EB40A ARM evaluation board that has ARM Angel 1.04
> running in the flash, and I can talk to this fine from the
> ARM-supplied AXD debugger. But I can't talk to it from arm-elf-gdb (I
> have v.6.1, compiled by macgraigor.com) which is running under cygwin
> on Windows 2000. arm-elf-gdb works just fine with the simulator
> target.

> I start up arm-elf-gdb, then do

> set remotebaud 9600
> target rdi com1

> The second command just hangs, I can see LEDs flashing to indicate
> that data is passing back and forth, but no response in gdb.

> Any ideas?

> - Dave

Re[2]: Can't talk to Angel debug monitor from arm-elf-gdb

[Dave Cleal]

Last time I'm going to do this. Just in case anyone else ever needs
to know, this now all works. The trick is to patch CDT (the Eclipse
plugin for C/C++ development) to recognise when you're connected via a
serial port, and to have it start the program with a "continue"
command not a "run" command. Everything thereafter works.

-- Dave


> (talking to myself)

> Eventually got around this by re-flashing to replace Angel with
> the Redboot monitor. arm-elf-gdb talks to that just fine as a remote
> target.

> I do have a remaining problem with my toolchain, which is that
> ideally, I'd like to develop in Eclipse. Eclipse won't interact nicely
> with arm-elf-gdb running a remote target. I'm not sure whether this is
> Eclipse sending the wrong commands, or arm-elf-gdb responding weirdly.
> Just before I start messing with Eclipse, has anyone got experience of
> this kind of set up (eclipse -> arm-elf-gdb -> remote target)?

> - Dave

>> Hi,

>> I've got an ATMEL EB40A ARM evaluation board that has ARM Angel 1.04
>> running in the flash, and I can talk to this fine from the
>> ARM-supplied AXD debugger. But I can't talk to it from arm-elf-gdb (I
>> have v.6.1, compiled by macgraigor.com) which is running under cygwin
>> on Windows 2000. arm-elf-gdb works just fine with the simulator
>> target.

>> I start up arm-elf-gdb, then do

>> set remotebaud 9600
>> target rdi com1

>> The second command just hangs, I can see LEDs flashing to indicate
>> that data is passing back and forth, but no response in gdb.

>> Any ideas?

>> - Dave

Re: Re[2]: Can't talk to Angel debug monitor from arm-elf-gdb

[Alain Magloire]

> 
> Last time I'm going to do this. Just in case anyone else ever needs
> to know, this now all works. The trick is to patch CDT (the Eclipse
> plugin for C/C++ development) to recognise when you're connected via a
> serial port, and to have it start the program with a "continue"
> command not a "run" command. Everything thereafter works.
> 

There was indeed a bug when using gdbserver, the state of the frontend
was incorrect, it should have consider the inferior "suspended" so to use
"continue" instead  "run"  since the inferior was already `loaded'.

Maybe MI commands like,
-target-select
-target-attach

should return an extra exec-async:

*stopped

Even if, like the case of -target-select there is no frame yet.
It would notify to the frontends that the inferior was loaded.

Re[4]: Can't talk to Angel debug monitor from arm-elf-gdb

[Dave Cleal]

Alain,

sounds correct: and my copy of Eclipse (v3.0.1) has code to do exactly
what you say in the GDBServer case. However, I'm working with GDB
talking to the Redboot debug monitor down a serial port, so actually,
GDBServer is not involved. I've written a patch which essentially
treats this case like the GDBServer case, which I'll submit to the CDT
project in due course.

-- Dave


>> 
>> Last time I'm going to do this. Just in case anyone else ever needs
>> to know, this now all works. The trick is to patch CDT (the Eclipse
>> plugin for C/C++ development) to recognise when you're connected via a
>> serial port, and to have it start the program with a "continue"
>> command not a "run" command. Everything thereafter works.
>> 

> There was indeed a bug when using gdbserver, the state of the frontend
> was incorrect, it should have consider the inferior "suspended" so to use
> "continue" instead  "run"  since the inferior was already `loaded'.

> Maybe MI commands like,
> -target-select
> -target-attach

> should return an extra exec-async:

> *stopped

> Even if, like the case of -target-select there is no frame yet.
> It would notify to the frontends that the inferior was loaded.

Re: Re[4]: Can't talk to Angel debug monitor from arm-elf-gdb

[Alain Magloire]

> 
> Alain,
> 
> sounds correct: and my copy of Eclipse (v3.0.1) has code to do exactly
> what you say in the GDBServer case. However, I'm working with GDB
> talking to the Redboot debug monitor down a serial port, so actually,
> GDBServer is not involved. I've written a patch which essentially
> treats this case like the GDBServer case, which I'll submit to the CDT
> project in due course.
> 

We could not ask for more.
Not that we are closing on CDT-2.1 release, so your patch
may end up in CDT-3.0(tied with Eclipse-3.1) ... this june 8-(.
But as long as you submitted a patch/PR to track the defect,
the folks working on the CDT/Debug/MI we'll be happy.

-- 
au revoir, alain
----
Aussi haut que l'on soit assis, on est toujours assis que sur son cul !!!