From: Yao Qi <yao@codesourcery.com>
To: Jon Beniston <jon@beniston.com>
Cc: <gdb@sourceware.org>
Subject: Re: Memory-mapped peripheral registers, remote protocol and memory maps
Date: Thu, 29 Nov 2012 15:51:00 -0000 [thread overview]
Message-ID: <50B78451.5000903@codesourcery.com> (raw)
In-Reply-To: <005301cdce23$e1b0f3e0$a512dba0$@beniston.com>
On 11/29/2012 07:22 PM, Jon Beniston wrote:
> In some cases, there might be a large variety of inter-mixed
> 8/16/32-bit registers, which you might not have the space to cater
> for in a small stub. Can we be sure that GDB will only generate a 'm
> 0x0x00d000 4' packet? It would be tricky for a stub to deal with a
The following command 'p' will only generate 'm' packet with the right size.
(gdb) p *(unsigned int *) 0x8048608
Sending packet: $m8048608,4#3f...Packet received: 5589e583
(gdb) p *(char *) 0x8048608
Sending packet: $m8048608,1#3c...Packet received: 55
I admit they are tricky.
> packet of a larger size (say if the register area is opened in a
> memory viewer). Also, it would be nice to prevent reads from certain
> addresses, in case they have side effects (i.e FIFOs, etc).
>
Something similar was done in codesourcery (by other people) to handle
memory-mapped register and side effect of reading registers (we call it
read sensitiveness, IIRC). The target description mechanism
(http://sourceware.org/gdb/current/onlinedocs/gdb/Target-Descriptions.html)
was enhanced, in which the name, width, mapped address and read
sensitiveness of each register is described. With these knowledge, GDB
can take care of memory-mapped register. However, these patches didn't
go to upstream.
--
Yao (é½å°§)
next prev parent reply other threads:[~2012-11-29 15:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-28 19:24 Jon Beniston
2012-11-29 9:16 ` Yao Qi
2012-11-29 11:23 ` Jon Beniston
2012-11-29 15:51 ` Yao Qi [this message]
2012-11-29 16:32 ` Jon Beniston
2012-11-29 17:23 ` Paul_Koning
2012-11-29 17:57 ` Jon Beniston
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