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

menu "Target options"

comment "General target options"

config ARCH

    string

    default "arm"     if ARCH_ARM

    default "mips"    if ARCH_MIPS

    default "x86"     if ARCH_x86

    default "x86_64"  if ARCH_x86_64

choice

    bool

    prompt "Target architecture:"

    default ARCH_x86

config ARCH_ARM

    bool

    prompt "arm"

    select ARCH_SUPPORTS_BE

    select ARCH_SUPPORTS_LE

config ARCH_MIPS

    bool

    prompt "mips"

    select ARCH_SUPPORTS_BE

    select ARCH_SUPPORTS_LE

config ARCH_x86

    bool

    prompt "x86"

    select ARCH_SUPPORTS_LE

config ARCH_x86_64

    bool

    prompt "x86_64"

    select ARCH_SUPPORTS_LE

endchoice

config ARCH_SUPPORTS_BE

    bool

    default n

config ARCH_SUPPORTS_LE

    bool

    default n

choice

    bool

    prompt "Endianness:"

config ARCH_BE

    bool

    prompt "Big endian"

    depends on ARCH_SUPPORTS_BE

config ARCH_LE

    bool

    prompt "Little endian"

    depends on ARCH_SUPPORTS_LE

endchoice

comment "Target optimisations"

config ARCH_ARCH

    string

    prompt "Achitecture level"

    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"

    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 architecutre does not

      offer this option.

config ARCH_CPU

    string

    prompt "Emit assembly for CPU"

    default ""

    help

      This specifies the name of the target ARM 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"

    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"

    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:"

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_SW

    bool

    prompt "software"

    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 ARCH_FLOAT_SW_LIBFLOAT

    bool

    prompt "Use libfloat"

    default n

    depends on ARCH_FLOAT_SW

    help

      For those targets upporting it, you can use libfloat for the software

      floating point emulation.

      Note that some versions of gcc have support code that supersedes libfloat,

      while others don't. Known version of gcc that don't have support code are

      versions prior to 3.0, and version above 4.0.

      You should check gcc before deciding to use libfloat.

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 CPU, tune, arch and FPU will be

      automaticaly used. You don't need to specify them here.

      Leave blank if you don't know better.

endmenu