Re: [ECOS] sam7s64 support and general eCos questions

[Andrew Lunn <andrew at lunn dot ch>]

On Sat, Dec 16, 2006 at 05:50:25PM -0800, Brent Picasso wrote:
> Hello all,
> 
> After quite a bit of research I started flailing my arms so I decided to post my questions here. 
> 
> I'm working with an Olimex development board provisioned with a sam7s64 processor ( http://www.olimex.com/dev/sam7-p64.html). I'm using their ARM-USB-OCD with their GCCFD distrubtion of GCC (v 4.0.2)
> 
> First with some general questions:
> 
> 
> 
> - What is the typical memory overhead required by the eCos kernel? elsewhere I've seen that it may be around 60K. 
> 
> - Can I launch my eCos application without redboot? i.e. can I simply
> burn my eCos application to flash and expect it to boostrap and launch from flash?
> 
> 
> And second, some problems I encountered attempting to compile an eCos application:
> 
> I've downloaded the latest from CVS, and configured the kernel in a fairly standard way that should be easily reproduced:
> 
> - For the Atmel AT91SAM7S-EK evaluation board
> - default package configuration
> - Selected the at91sam7s64 variant under the Atmel AT91SAM7 HAL
> - Selected (or rather, kept) ROM startup and address in flash the image should live (0x00100000)
> - For the conflicts that were presented I accepted the default suggestions.
> 
> The build executes fine- however, when I attempt to compile a simple 'do nothing' void main() app I receive the following error:
> 
> I've configued a simple 'do nothing' void main() app- when I compile I receive the following:
> 
> bash-3.2$ arm-elf-gcc -g -I/ecos-c/projects/cfi/cfi_install/include hello.c -L/ecos-c/projects/cfi/cfi_install/lib -Ttarget.ld -nostdlib/ecos-c/gccfd/gnuarm/bin/../lib/gcc/arm-elf/4.0.2/../../../../arm-elf/bin/ld: address 0x2048bc of a.out section .bss is not within region ram

It has run out of RAM.

The AT91SAM764 has 16Kbytes of RAM. This is too small for eCos
really. The AT91SAM7s256 is much more suitable with 64KBytes of
RAM. Even so, you still have to be careful with RAM usage, make sure
your configure your stacks to be as small as possible. The default 4K
normally wastes space.

         Andrew

-- 
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss