[ECOS] Problem downloading test programs (i386 pc)

[ECOS] Problem downloading test programs (i386 pc)

[davide_ciminaghi]

Hi,

I'm just doing some experiments with ecos and an i386 PC as a target
(the PC has 8MB RAM).
The host machine is a PC running Linux.
Just to summarize what I did:

1) Downloaded the ecos sources from anonymous CVS (I updated my sources
the last time less than a week ago).
2) Created my ecos working directory (mkdir ecos-work ; cd ecos-work)
3) Configured ecos for the i386 pc target (ecosconfig new pc stubs)
4) Created a build tree (ecosconfig tree)
5) Built the gdb image and tests (make ; make tests): no errors and
    everything seems to work exactly as described on the docs.
6) Created a boot floppy for the target (I can't remember the exact
    command now, but it works with no errors).
7) Booted the target with the floppy and connected the target to the
   host via a serial cable.
8) Started Insight on the host and successfully got a connection with
   the target.
9) Verified I could inspect both the target CPU registers and memory.
10)Tried downloading the test programs.

Here comes the problem (which shows whichever the test program I pick):
what happens when I try downloading is that the download dialog appears
and I get the message "downloading text section" (or something like
that).
For a few seconds I can see the number of downloaded bytes increasing.
When such number reaches about 6000, it stops and the target seems to
hang. As a matter of fact after such a download I have to restart the
target if I want to get the connection up again.
If I do the download with remote debugging on (set debug remote 1 from
the Insight console window) I can just see some messages ("Ignoring
packet error") displayed at a rate of about 1 every 20sec, after having
downloaded about 6000 bytes (again).

I did the same download with a "plain" gdb (the one I have installed on
my Linux PC), but got exactly the same problem.
I tried to slow down the connection speed to 19200 baud, but nothing
changed (the download always stops at 6000).
I even tried modifying the target's set up parameters
(enable/disable "ROM BIOS shadowing" and a mysterious, for me,
"RAM 256/384kB/Disabled relocation"). Doing so, the only change I can
notice is that the download stops at 5000
bytes instead of 6000 (WORSE!!).

Now the only thing I can think of is that the program I want to
download could be overwriting either the gdb stub
on the target or some memory area owned by the gdb stub itself. Is that
possible ? What can I do to avoid this ?
Has anybody else come across the same problem ? (I checked the messages
on the list but till now couldn't find anything
really close to my situation, at least for what concerns the PC target).

Please consider I'm a beginner with ecos and with i386 based embedded
systems, so excuse me if I've written something
(too) wrong or (too) obvious.

Thanks in advance and regards
Davide Ciminaghi

Re: [ECOS] Problem downloading test programs (i386 pc)

[Jesper Skov]

>3) Configured ecos for the i386 pc target (ecosconfig new pc stubs)
>4) Created a build tree (ecosconfig tree)
>5) Built the gdb image and tests (make ; make tests): no errors and 
>    everything seems to work exactly as described on the docs.

This is wrong: you need to build stubs in one tree, and the tests in
another tree. Otherwise they end up having the same memory layout,
trashing the stubs as you download a test.

For the tests, do:

mkdir pc-tests; cd pc-tests
ecosconfig new pc
make tests


Jesper

Re: [ECOS] Problem downloading test programs (i386 pc)

[Andreas Bürgel]

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Hi, 

try to change your memory-map - the .ldi file - so that the start
address of the rom_vectors-section - the second parameter inside the
brackets - gets bigger. 0x20000 should work. 
This method worked for me when I had a very similar problem. When doing
this you give the stub more room to live, your problem may result from
overwriting parts of the stub by loading the application.

-----------------------------------------------------
i.A. Andreas Bürgel     GenoLogic GmbH
     Software Engineer  Joseph-von-Fraunhofer-Str. 13
                        D-44227 DORTMUND
                        Germany               
                        
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