Re: eCos with arm eabi compiler

Re: eCos with arm eabi compiler

[Gary Thomas]

taiyun@sunnorth.com.cn wrote:
> Dear all:
> We are now porting eCos kernel to our platform, EVB named
> spaca556g(arm926ej-s). We choose a gcc4.2 eabi
> compiler(http://www.codesourcery.com/gnu_toolchains/arm/download.html). The
> reason of choosing this compiler is that an EABI compiler can be completely
> compatible with ARM RealView libraries. With this arm-eabi compiler,
> libraries built from realview can be used.
> But there are some problems using this eabi compiler. Because of different
> constructing method between arm-elf compiler and eabi compiler,
> constructors of global instances can't be invoked automatically when using
> the eabi compiler. As a result, we have to make changes to arm.ld and
> hal_misc.c files.
> 
> NOTE: arm-elf compiler use .ctor section and 2 labels(__CTOR_LIST__,
> __CTOR_END__) to invoke constructors, BUT arm-eabi compiler use .init_array
> section and lables(__init_array_start, __init_array_end)
> 
> arm-eabi compiler's linker script has different sections from arm-elf
> compiler's, e.g: .ARM.extab, .ARM.exidx and .ARM.attributes 0, these 3
> sections are own in arm-eabi compiler. These sections should be added to
> arm.ld, aren't they? If so, there are 2 ways to achieve this goal. One is
> making direct changes to arm.ld and adding corresponding sections'
> definitions. The other is setting up a new arch-eabi directory in hal/arm,
> which is only for arm-eabi compiler. Which is the best?

Add a CDL option to the ARM arch which controls this.  Then
you can have everything be automatic; compiler names (arm-elf-gcc
vs. arm-eabi-gcc, etc), linker script, how the constructors are
handled, etc.  The rest of the code should stay the same; it
will still be the same ARM hardware underneath.

n.b. if you were to split into an arm-eabi directory, I think there
would have to be *way* too much duplication (which inevitably leads
to code-rot)

BTW, in my mind, this is a development question (hence I changed
the mailing list).  The eCos maintainer list is for questions/issues
dealing with licensing, distribution, etc.


-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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