Re: [avr-gcc-list] IAR vs GCC (Larry Barello)

[TODD BATZLER]

Thanks for the reply.  The reason I'm looking into a string in an absolute 
location is so I can go to the field and query my deeply embedded micro to 
determine what software revision it contains.  We're using AVR's in a wide 
variety of applications and a "standard ID string" at a fixed location in the 
program space seemed to be the simplest solution for a limited field programmer 
device to ID the software revision level if it always knew where to look, 
regardless of the actual micro application.  I'm certainly open to any other 
suggestions it anyone has a better system for field level revision 
identification where the service personnel are far from technically competent 
and the embedded application has no interface but the spi programming port.

Todd Batzler
Senior Staff Engineer
Miller Electric Mfg. Co.
P.O. Box 1079
Appleton, WI  54912-1079
Phone:  (920) 735-4230
Fax:  (920) 735-4488
Email:  address@hidden


>>> "Larry Barello" <address@hidden> 06/13/01 10:27AM >>>
Sorry, I can't help you with either of your questions.  IAR is certainly a
professional development environment.  But, as I use GCC I find that most
everything I need to do has been covered.  The extra's in IAR seem to be
archaic or there to support other architectures.  I am sure, if you knew
how to run the gnu linker, you could do what you want. But I am the wrong
person to ask.

I question the need to place strings at an absolute location.  But, what do
I know...

----- Original Message -----
From: "TODD BATZLER" <address@hidden>
To: <address@hidden>
Sent: Wednesday, June 13, 2001 5:26 AM
Subject: [avr-gcc-list] IAR vs GCC (Larry Barello)


My company is currently using the IAR Embedded WorkBench as the "official"
compiler for product development. I've been using GCC for everything of a
personal nature.  I've been struggling with GCC over a feature that IAR
makes very pain free, which is placing a string of bytes at an absolute
location in the code segment, then having the linker to be smart enough to
"wrap" the other code segments around this absolute segment so as to not
waste large chunks of the CODE section.  I've managed to dig up enough
information on linker scripts to modify one to create the required absolute
field in the rom image and place my required data there.  However, if my
relocatable code gets larger than my absolute address minus the start of
the .text section, I get a warning that the linker location counter can not
be "backed up".  Which makes sense.  Any ideas on how to instruct the
linker to check the available space between defined section starts and any
absolute sections and then have it figure out when it can place code in
that section (if it will fit) or place it after the absolute section (if it
will not)?

Also, do you know how to find out what was specifically done to the "avr-"
variants of the GCC binaries to make them different from the "standard" GCC
release files.  I'm assuming that support for some of the architectures was
removed, plus a bunch of other things.  There's no specific documentation
for the avr-ld, avr-objcopy, etc files.

Thanks for the attention.

Todd Batzler
address@hidden