Re: Interrupting remote targets from GDB

[Daniel Jacobowitz <drow at false dot org>]

On Thu, Nov 17, 2005 at 11:20:43AM -0700, Kevin Buettner wrote:
>     set remotebreak
> 	If set to on, GDB sends a BREAK signal to the remote when you
> 	press the Ctrl-C key to interrupt the program running on the
> 	remote.  If set to off, GDB sends the `Strl-C' character
> 	instead.  The default is off, since most remote systems expect
> 	to see `Ctrl-C' as the interrupt signal.

Mind fixing the Strl-C ? ;-)

> I think this documentation is fine, but would also like to see some
> suitable documentation added to the section describing the GDB remote
> protocol.  I suggest that a section called "Interrupts" be added in
> between the sections "Register Packet Format" and "Examples".  I propose
> that it contain the following text:
> 
>     When a program on the remote target is running, GDB may attempt
>     to interrupt it by sending a `Ctrl-C' or a BREAK, control of which
>     is specified via GDB's `remotebreak' setting.  The precise meaning
>     of BREAK is defined by the transport mechanism and may, in fact,
>     be undefined.  `Ctrl-C', on the other hand, is defined for all
>     transport mechanisms and is represented by sending the single byte
>     0x03.  `Ctrl-C' must not be sent as part of a packet as defined in
>     the "Overview".
>     
>     Stubs are not required to recognize these interrupt mechanisms and
>     the precise meaning associated with receipt of the interrupt is
>     implementation defined.  If the stub is successful at interrupting
>     the running program, it is expected that it will send one of the
>     `Stop Reply Packets' to GDB as a result of successfully stopping
>     the program.
> 
> Comments?

Fine by me; can we also add a word about what to do with interrupts
when the target is stopped?  I believe they should be dropped rather
than responded to, per conversation on gdb@ earlier this month.

-- 
Daniel Jacobowitz
CodeSourcery, LLC