Re: [ECOS] Thumb support for ARM

["Lewin A.R.W. Edwards" <larwe at larwe dot com>]

>According to the eCOS web page at
>http://sources.redhat.com/ecos/tools/win-thumb-elf.html
>the current 2.95.2 does not support arm thumb, what is the issue?  And when
>might this be fixed?

The issue isn't that 2.95.2 doesn't support arm-thumb, the issue is that it 
won't successfully compile eCos in thumb mode.

There doesn't seem to be a complete solution to that problem at the moment. 
What I have done is to use a recent CVS snapshot of the gcc sources, 
compiled for arm-elf. (Newer versions of gcc support -mthumb to generate 
Thumb code). It still is not possible to compile eCos as Thumb code (known 
gcc bug). However you can compile eCos in ARM mode, and specify the 
-mthumb-interwork switch. You can then compile your app in thumb mode with 
-mthumb -mthumb-interwork).

Note that in order to achieve this, you will also need to have the standard 
libraries built with thumb interworking enabled. Jonathan Larmour posted 
instructions for this a couple of weeks back, check the list archives.

=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/

"Und setzet ihr nicht das Leben ein,
Nie wird euch das Leben gewonnen sein."