config/arch/arm.in.2
author "Yann E. MORIN" <yann.morin.1998@free.fr>
Thu Jan 10 00:11:17 2013 +0100 (2013-01-10)
changeset 3158 1161ea79915b
parent 3150 1d6fd9bde73c
child 3159 fb71cad4b085
permissions -rw-r--r--
arch/arm: add option to use *eabihf tuples

Toolchains that use the hard-float ABI now are to be denoted by a tuple
ending in *eabihf, while the prevbious *eabi is now an indication that
the toolchain uses the softfloat ABI.

This is purely a cosmetic thing, for distros to differentiate their
hardfloat-ABI ports from their softfloat-ABI ports.

(note: softfloat ABI does not mean that it is using softfloats; it can
be using hardfloat instructions, but using the softfloat ABI).

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
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# ARM specific configuration file
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config ARCH_ARM_MODE
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    string
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    default "arm"   if ARCH_ARM_MODE_ARM
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    default "thumb" if ARCH_ARM_MODE_THUMB
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choice
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    bool
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    prompt "Default instruction set mode"
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    default ARCH_ARM_MODE_ARM
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config ARCH_ARM_MODE_ARM
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    bool
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    prompt "arm"
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    help
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      Defaults to emitting instructions in the ARM mode.
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config ARCH_ARM_MODE_THUMB
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    bool
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    prompt "thumb"
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    help
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      Defaults to emitting instructions in the THUMB mode.
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endchoice
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config ARCH_ARM_INTERWORKING
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    bool
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    prompt "Use Thumb-interworking (READ HELP)"
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    help
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      Excerpt from the gcc manual:
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      > Generate code which supports calling between the ARM and Thumb
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      > instruction sets. Without this option the two instruction sets
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      > cannot be reliably used inside one program. The default is
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      > [not to use interwork], since slightly larger code is generated
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      > when [interwork] is specified.
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      NOTE: Interworking in crosstool-NG is not sell-tested. Use at your
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            own risks, and report success and/or failure.
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config ARCH_ARM_EABI
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    bool
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    prompt "Use EABI"
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    default y
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    help
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      Set up the toolchain so that it generates EABI-compliant binaries.
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config ARCH_ARM_TUPLE_USE_EABIHF
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    bool
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    prompt "append 'hf' to the tuple (EXPERIMENTAL)"
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    depends on ARCH_FLOAT_HW
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    depends on ARCH_ARM_EABI    # Until we only support that...
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    depends on EXPERIMENTAL
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    help
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      Is you say 'y' here, then the tuple for the toolchain will end
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      up with *eabihf, instead of the usual *eabi.
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      *eabihf is used to denote that the toolchain *is* using the
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      hard-float ABI, while *eabi is just an indication of using the
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      soft-float ABI.
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      Ie. all one can say is:  *eabihf ⊢ hard-float ABI
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      Saying 'n' here does *not* impact the ability of the toolchain to
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      generate hard-float instructions with the hard-float ABI. It is a
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      purely cosmetic thing, used by distros to differentiate their
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      hard-float-ABI-using ports from their soft-float-ABI-using ports.
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      (eg. Debian Wheezy and above).
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      This is an option, as not all versions of gcc/binutils do support
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      such tuple, and fail to build with *eabihf. Stock gcc version up
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      to, and including 4.7.2 have an issue or another with *eabihf.
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      This option is here for the future.
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      Say 'n', unless you are trying to fix gcc to properly recognise
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      the *eabihf tuples.
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config ARCH_ARM_ABI_OK
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    bool
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    default y
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    depends on ! ARCH_ARM_EABI
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    select ARCH_SUPPORTS_WITH_ABI