[ECOS] EB55 target & Thumb instruction set

Jonathan Larmour jifl@eCosCentric.com
Wed Mar 3 17:33:00 GMT 2004

Eric de Jong wrote:
>>>When I tried to build eCos with AT91EB55 target template and HAL's option
>>>"Enable Thumb instruction set" I've got the build error:
>>>arm-elf-gcc  ...
> /ecos-c/cygwin/opt/ecos/cvs_rep/packages/hal/arm/arch/current/src/vectors.S
> The led macro in hal_platform_setup.h uses a mov instruction with an 8bit  constant.
> This is supported in the arm instruction set, but not in the thumb instruction set.
> Replace the 'mov r1,#' instructions with 'ldr r1, =' in the led macro code.

I haven't thought about this much, but this doesn't sound right. the 
parameter is a 16-bit half-word, so can't possibly fit into a 16-bit 
instruction! Sure this change will let it compile, but the led macros won't 
actually work. Or is that all you meant?

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