crosstool-ng/config/target.in

# Target definition: architecture, optimisations, etc...

menu "Target options"

config ARCH
    string

# Pre-declare target optimisation variables
config ARCH_SUPPORTS_BOTH_MMU
config ARCH_SUPPORTS_BOTH_ENDIAN
config ARCH_SUPPORTS_32
config ARCH_SUPPORTS_64
config ARCH_SUPPORTS_WITH_ARCH
config ARCH_SUPPORTS_WITH_ABI
config ARCH_SUPPORTS_WITH_CPU
config ARCH_SUPPORTS_WITH_TUNE
config ARCH_SUPPORTS_WITH_FLOAT
config ARCH_SUPPORTS_WITH_FPU
config ARCH_SUPPORTS_SOFTFP

config ARCH_DEFAULT_HAS_MMU
config ARCH_DEFAULT_BE
config ARCH_DEFAULT_LE
config ARCH_DEFAULT_32
config ARCH_DEFAULT_64

config ARCH_ARCH
config ARCH_ABI
config ARCH_CPU
config ARCH_TUNE
config ARCH_FPU
config ARCH_BE
config ARCH_LE
config ARCH_32
config ARCH_64
config ARCH_BITNESS
config ARCH_FLOAT_HW
config ARCH_FLOAT_SW
config TARGET_CFLAGS
config TARGET_LDFLAGS

source "config.gen/arch.in"

#--------------------------------------
comment "Generic target options"

#--------------------------------------
config MULTILIB
    bool
    prompt "Build a multilib toolchain (EXPERIMENTAL)"
    depends on EXPERIMENTAL
    help
      If you say 'y' here, then the toolchain will also contain the C library
      optimised for some variants of the selected architecture, besides the
      default settings.
      
      This means the build time of the C library will be in O(nb_variants).
      
      The list of variants is dependent on the architecture, and is hard-coded
      in gcc, so it is not possible to say what variants to support, only
      whether hard-coded variants should be supported or not.

#--------------------------------------
config ARCH_SUPPORTS_BOTH_MMU
    bool

config ARCH_DEFAULT_HAS_MMU
    bool

config ARCH_USE_MMU
    bool
    prompt "Use the MMU" if ARCH_SUPPORTS_BOTH_MMU
    default y if ARCH_DEFAULT_HAS_MMU
    help
      If your architecture has an MMU and you want to use it,
      say 'Y' here.
      
      OTOH, if you don't want to use the MMU, or your arch
      lacks an MMU, say 'N' here.
      
      Note that some architectures (eg. ARM) has variants that
      lacks an MMU (eg. ARM Cortex-M3), while other variants
      have one (eg. ARM Cortex-A8).

#--------------------------------------
config ARCH_SUPPORTS_BOTH_ENDIAN
    bool

config ARCH_DEFAULT_BE
    bool

config ARCH_DEFAULT_LE
    bool

choice
    bool
    prompt "Endianness:"
    depends on ARCH_SUPPORTS_BOTH_ENDIAN
    default ARCH_BE if ARCH_DEFAULT_BE
    default ARCH_LE if ARCH_DEFAULT_LE

config ARCH_BE
    bool
    prompt "Big endian"

config ARCH_LE
    bool
    prompt "Little endian"

endchoice

config ARCH_ENDIAN
    string
    depends on ARCH_SUPPORTS_BOTH_ENDIAN
    default "big"       if ARCH_BE
    default "little"    if ARCH_LE

#--------------------------------------
config ARCH_SUPPORTS_32
    bool

config ARCH_SUPPORTS_64
    bool

config ARCH_DEFAULT_32
    bool

config ARCH_DEFAULT_64
    bool

config ARCH_BITNESS
    int
    default "32"    if ARCH_32
    default "64"    if ARCH_64

choice
    bool
    prompt "Bitness:"
    default ARCH_32 if ARCH_DEFAULT_32
    default ARCH_64 if ARCH_DEFAULT_64

config ARCH_32
    bool
    prompt "32-bit"
    depends on ARCH_SUPPORTS_32

config ARCH_64
    bool
    prompt "64-bit"
    depends on ARCH_SUPPORTS_64

endchoice

#--------------------------------------
comment "Target optimisations"

config ARCH_SUPPORTS_WITH_ARCH
    bool

config ARCH_SUPPORTS_WITH_ABI
    bool

config ARCH_SUPPORTS_WITH_CPU
    bool

config ARCH_SUPPORTS_WITH_TUNE
    bool

config ARCH_SUPPORTS_WITH_FLOAT
    bool

config ARCH_SUPPORTS_WITH_FPU
    bool

config ARCH_SUPPORTS_SOFTFP
    bool

config ARCH_ARCH
    string
    prompt "Architecture level"
    depends on ARCH_SUPPORTS_WITH_ARCH
    default ""
    help
      GCC uses this name to determine what kind of instructions it can emit
      when generating assembly code. This option can be used in conjunction
      with or instead of the ARCH_CPU option (above), or a (command-line)
      -mcpu= option.
      
      This is the configuration flag --with-arch=XXXX, and the runtime flag
      -march=XXX.
      
      Pick a value from the gcc manual for your choosen gcc version and your
      target CPU.
      
      Leave blank if you don't know, or if your target architecture does not
      offer this option.

config ARCH_ABI
    string
    prompt "Generate code for the specific ABI"
    depends on ARCH_SUPPORTS_WITH_ABI
    default ""
    help
      Generate code for the given ABI.

      This is the configuration flag --with-abi=XXXX, and the runtime flag
      -mabi=XXX.

      Pick a value from the gcc manual for your choosen gcc version and your
      target CPU.

      Leave blank if you don't know, or if your target architecture does not
      offer this option.

config ARCH_CPU
    string
    prompt "Emit assembly for CPU"
    depends on ARCH_SUPPORTS_WITH_CPU
    default ""
    help
      This specifies the name of the target processor. GCC uses this name
      to determine what kind of instructions it can emit when generating
      assembly code.
      
      This is the configuration flag --with-cpu=XXXX, and the runtime flag
      -mcpu=XXX.

      Pick a value from the gcc manual for your choosen gcc version and your
      target CPU.
      
      Leave blank if you don't know, or if your target architecture does not
      offer this option.

config ARCH_TUNE
    string
    prompt "Tune for CPU"
    depends on ARCH_SUPPORTS_WITH_TUNE
    default ""
    help
      This option is very similar to the ARCH_CPU option (above), except
      that instead of specifying the actual target processor type, and hence
      restricting which instructions can be used, it specifies that GCC should
      tune the performance of the code as if the target were of the type
      specified in this option, but still choosing the instructions that it
      will generate based on the cpu specified by the ARCH_CPU option
      (above), or a (command-line) -mcpu= option.
      
      This is the configuration flag --with-tune=XXXX, and the runtime flag
      -mtune=XXX.
      
      Pick a value from the gcc manual for your choosen gcc version and your
      target CPU.
      
      Leave blank if you don't know, or if your target architecture does not
      offer this option.

config ARCH_FPU
    string
    prompt "Use specific FPU"
    depends on ARCH_SUPPORTS_WITH_FPU
    default ""
    help
      On some targets (eg. ARM), you can specify the kind of FPU to emit
      code for.

      This is the configuration flag --with-fpu=XXX, and the runtime flag
      -mfpu=XXX.
      
      See below wether to actually emit FP opcodes, or to emulate them.
      
      Pick a value from the gcc manual for your choosen gcc version and your
      target CPU.
      
      Leave blank if you don't know, or if your target architecture does not
      offer this option.

choice
    bool
    prompt "Floating point:"
    depends on ARCH_SUPPORTS_WITH_FLOAT

config ARCH_FLOAT_HW
    bool
    prompt "hardware (FPU)"
    help
      Emit hardware floating point opcodes.
      
      If you've got a processor with a FPU, then you want that.
      If your hardware has no FPU, you still can use HW floating point, but
      need to compile support for FPU emulation in your kernel. Needless to
      say that emulating the FPU is /slooowwwww/...
      
      One situation you'd want HW floating point without a FPU is if you get
      binary blobs from different vendors that are compiling this way and
      can't (don't wan't to) change.

config ARCH_FLOAT_SOFTFP
    bool
    prompt "softfp (FPU)"
    depends on ARCH_SUPPORTS_SOFTFP
    help
      Emit hardware floating point opcodes but use the software
      floating point calling convention.

      Architectures such as ARM use different registers for passing
      floating point values depending on if they're in software mode
      or hardware mode.  softfp emits FPU instructions but uses the
      software FP calling convention allowing softfp code to
      interoperate with legacy software only code.

      If in doubt, use 'software' or 'hardware' mode instead.

config ARCH_FLOAT_SW
    bool
    prompt "software (no FPU)"
    help
      Do not emit any hardware floating point opcode.
      
      If your processor has no FPU, then you most probably want this, as it
      is faster than emulating the FPU in the kernel.

endchoice

config TARGET_CFLAGS
    string
    prompt "Target CFLAGS"
    default ""
    help
      Used to add specific options when compiling libraries of the toolchain,
      that will run on the target (eg. libc.so).
      
      Note that the options above for ARCH, ABI, CPU, TUNE and FPU will be
      automatically used. You don't need to specify them here.
      
      Leave blank if you don't know better.

config TARGET_LDFLAGS
    string
    prompt "Target LDFLAGS"
    default ""
    help
      Used to add specific options when linking libraries of the toolchain,
      that will run on your target.
      
      Leave blank if you don't know better.

config ARCH_FLOAT
    string
    default ""       if ! ARCH_SUPPORTS_WITH_FLOAT
    default "hard"   if ARCH_FLOAT_HW
    default "soft"   if ARCH_FLOAT_SW
    default "softfp" if ARCH_FLOAT_SOFTFP

source "config.gen/arch.in.2"

endmenu