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Re: EB55 target & Thumb instruction set
- From: Jonathan Larmour <jifl at eCosCentric dot com>
- To: Eric de Jong <list_ericdejong_10 at gmx dot net>
- Cc: ecos-discuss at sources dot redhat dot com
- Date: Wed, 03 Mar 2004 17:33:16 +0000
- Subject: Re: [ECOS] EB55 target & Thumb instruction set
- References: <702089944.20040225162310@pisem.net> <002301c3fb88$d5112320$e33922c7@eric>
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?
Jifl
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