public inbox for sid@sourceware.org
 help / color / mirror / Atom feed
From: "Robert Cragie" <rcc@jennic.com>
To: "Frank Ch. Eigler" <fche@redhat.com>
Cc: <sid@sources.redhat.com>
Subject: RE: Trying to run on pid7t board
Date: Wed, 21 Aug 2002 11:15:00 -0000	[thread overview]
Message-ID: <NDBBLOIOMLKELOJBAPAGAEHPCOAA.rcc@jennic.com> (raw)
In-Reply-To: <20020821123523.B7180@redhat.com>

> On Wed, Aug 21, 2002 at 05:24:50PM +0100, Robert Cragie wrote:
> > [...]
> > I then connect to it using gdb (insight 5.0), and connect
> successfully to
> > the target. I then download the test, and inspect memory at 0x8000, no
> > problem, it's there. However, when I start to run, it hits the
> breakpoint I
> > have set, but I notice all the code has vanished at 0x8000, and it's
> > executing 0x00000000 each time. Any idea what's going on?
>
> Yes, that is odd.  Can you tell me why you think it's executing 0x0?
> You could show gdb's side of the conversation, either a console script,
> or maybe even include packet traces as per `(gdb) set remote debug 3'.

If I specify --trace-semantics in the sid command line I get the following:

0x8040: LDR_PRE_INC_IMM_OFFSET	gr[0]:=0x8048
0x8044: MOV_REG_IMM_SHIFT	pc:=0x8048
0x8048: LDR_PRE_INC_IMM_OFFSET	gr[0]:=0xb000020
0x804c: STR_PRE_INC_IMM_OFFSET	memory[0xb000020]:=0xb000020
0x8050: AND_REG_IMM_SHIFT
0x8054: AND_REG_IMM_SHIFT
0x8058: AND_REG_IMM_SHIFT
0x805c: AND_REG_IMM_SHIFT

...AND_REG_IMM_SHIFT looks like andeq r0,r0,r0 to me (i.e. NOP). I stepped
through the code and sure enough what happens is that indeed the first three
opcodes run OK, but when the fourth opcode is run, it screws up thereafter -
all the memory gets set to 0.

On the PID board, 'str r0,[r0]', where r0 is 0xb000020, changes the mapping
of the PID board mapping RAM to 0x0000000 instead of ROM - if the REMAP
board link (LK18) is in place. So it looks like the simulation of this is
doing something odd causing it to go wrong - I would expect it to just carry
on, as I would guess the software component of the simulation would have
already remapped (as a debug monitor on a real board would have), and once
this is done, it's done until the next reset.

Robert Cragie, Design Engineer
_______________________________________________________________
Jennic Ltd, Furnival Street, Sheffield, S1 4QT,  UK
http://www.jennic.com  Tel: +44 (0) 114 281 2655


  reply	other threads:[~2002-08-21 18:15 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-08-21  9:24 Robert Cragie
2002-08-21  9:35 ` Frank Ch. Eigler
2002-08-21 11:15   ` Robert Cragie [this message]
2002-08-21 11:31     ` Frank Ch. Eigler
2002-08-22  4:48       ` Robert Cragie
2002-08-22  6:22         ` Frank Ch. Eigler
2002-08-22  7:11           ` Ben Elliston
2002-08-22 10:09           ` Robert Cragie

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=NDBBLOIOMLKELOJBAPAGAEHPCOAA.rcc@jennic.com \
    --to=rcc@jennic.com \
    --cc=fche@redhat.com \
    --cc=sid@sources.redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).