Re: [avr-gcc-list] SRAM Usage

[Larry Barello]

You need the compiler from a couple months ago, vs the one on Volkers web site which is over a year old.  The new compiler packs SRAM properly.  Try:  http://combio.de/avr/ for the PC and Linux versions. 

 

Beware: there are a few issues with the new compiler.

1. Register passing conventions have changed R24, R22, R20.. for byte P1, P2, P3...

2. Linker messes up eeprom section (add "-R .eeprom" to both hex and avrobj targets)

3. The compiler was built with weird address range for eeprom so you need to relocate the eeprom to zero (add "--change-section-lma .eeprom=0" to eeprom target)

 

Cheers!

----- Original Message -----

From: Peter Bosscha

Hi,

 

I'm using the windows port of AVR-GCC (Volker Oth) and have completed a few projects.

Only recently I've discovered that the linker seems to be rather generous with SRAM.

Looking at the map file I find that between modules of a project there is always a fill until the next 0 nibble, I could define a single byte in a module which then actually wastes another 15 bytes. The same happens when I mix bytes and arrays of chars, again there is an allignment, this time within the module,  to the next nibble.

 

Anyone any ideas ? I would expect that one can adjust the linker to do this differently ?

 

Thanks in advance

 

Peter Bosscha