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7131764f9c
Rationale: Most of the time, soft-float problems are caused by this sucker of gcc: it has support for soft float for all of the targets I've tried so far, but does not activate this code until you dwelve into half a dozen of files to make it accept to build and link the support code... So, yes: gcc has soft-float support. And again, yes: gcc is a sucker.
198 lines
5.2 KiB
Plaintext
198 lines
5.2 KiB
Plaintext
# Target definition: architecture, optimisations, etc...
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menu "Target options"
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comment "General target options"
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config ARCH
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string
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default "arm" if ARCH_ARM
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default "mips" if ARCH_MIPS
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default "x86" if ARCH_x86
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default "x86_64" if ARCH_x86_64
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choice
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bool
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prompt "Target architecture:"
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default ARCH_x86
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config ARCH_ARM
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bool
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prompt "arm"
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select ARCH_SUPPORTS_BOTH_ENDIAN
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config ARCH_MIPS
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bool
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prompt "mips"
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select ARCH_SUPPORTS_BOTH_ENDIAN
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config ARCH_x86
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bool
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prompt "x86"
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config ARCH_x86_64
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bool
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prompt "x86_64"
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endchoice
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config ARCH_SUPPORTS_BOTH_ENDIAN
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bool
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default n
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choice
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bool
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prompt "Endianness:"
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depends on ARCH_SUPPORTS_BOTH_ENDIAN
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config ARCH_BE
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bool
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prompt "Big endian"
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config ARCH_LE
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bool
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prompt "Little endian"
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endchoice
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comment "Target optimisations"
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config ARCH_ARCH
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string
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prompt "Achitecture level"
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default ""
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help
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GCC uses this name to determine what kind of instructions it can emit
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when generating assembly code. This option can be used in conjunction
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with or instead of the ARCH_CPU option (above), or a (command-line)
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-mcpu= option.
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This is the configuration flag --with-arch=XXXX, and the runtime flag
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-march=XXX.
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Pick a value from the gcc manual for your choosen gcc version and your
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target CPU.
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Leave blank if you don't know, or if your target architecture does not
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offer this option.
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config ARCH_ABI
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string
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prompt "Generate code for the specific ABI"
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default ""
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help
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Generate code for the given ABI.
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This is the configuration flag --with-abi=XXXX, and the runtime flag
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-mabi=XXX.
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Pick a value from the gcc manual for your choosen gcc version and your
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target CPU.
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Leave blank if you don't know, or if your target architecutre does not
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offer this option.
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config ARCH_CPU
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string
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prompt "Emit assembly for CPU"
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default ""
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help
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This specifies the name of the target processor. GCC uses this name
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to determine what kind of instructions it can emit when generating
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assembly code.
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This is the configuration flag --with-cpu=XXXX, and the runtime flag
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-mcpu=XXX.
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Pick a value from the gcc manual for your choosen gcc version and your
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target CPU.
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Leave blank if you don't know, or if your target architecture does not
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offer this option.
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config ARCH_TUNE
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string
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prompt "Tune for CPU"
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default ""
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help
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This option is very similar to the ARCH_CPU option (above), except
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that instead of specifying the actual target processor type, and hence
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restricting which instructions can be used, it specifies that GCC should
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tune the performance of the code as if the target were of the type
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specified in this option, but still choosing the instructions that it
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will generate based on the cpu specified by the ARCH_CPU option
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(above), or a (command-line) -mcpu= option.
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This is the configuration flag --with-tune=XXXX, and the runtime flag
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-mtune=XXX.
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Pick a value from the gcc manual for your choosen gcc version and your
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target CPU.
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Leave blank if you don't know, or if your target architecture does not
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offer this option.
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config ARCH_FPU
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string
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prompt "Use specific FPU"
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default ""
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help
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On some targets (eg. ARM), you can specify the kind of FPU to emit
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code for.
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This is the configuration flag --with-fpu=XXX, and the runtime flag
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-mfpu=XXX.
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See below wether to actually emit FP opcodes, or to emulate them.
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Pick a value from the gcc manual for your choosen gcc version and your
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target CPU.
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Leave blank if you don't know, or if your target architecture does not
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offer this option.
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choice
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bool
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prompt "Floating point:"
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config ARCH_FLOAT_HW
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bool
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prompt "hardware (FPU)"
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help
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Emit hardware floating point opcodes.
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If you've got a processor with a FPU, then you want that.
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If your hardware has no FPU, you still can use HW floating point, but
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need to compile support for FPU emulation in your kernel. Needless to
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say that emulating the FPU is /slooowwwww/...
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One situation you'd want HW floating point without a FPU is if you get
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binary blobs from different vendors that are compiling this way and
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can't (don't wan't to) change.
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config ARCH_FLOAT_SW
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bool
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prompt "software"
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help
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Do not emit any hardware floating point opcode.
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If your processor has no FPU, then you most probably want this, as it
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is faster than emulating the FPU in the kernel.
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endchoice
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config TARGET_CFLAGS
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string
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prompt "Target CFLAGS"
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default ""
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help
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Used to add specific options when compiling libraries of the toolchain,
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that will run on the target (eg. libc.so).
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Note that the options above for CPU, tune, arch and FPU will be
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automaticaly used. You don't need to specify them here.
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Leave blank if you don't know better.
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endmenu
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