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82072d0cbc
On some arches (e.g. MIPS) the options like -mabi do not work if specified more than once (see the comment in 100-gcc.sh). Therefore, we need to determine which of the options produced by <arch>.sh can be passed to multilib builds and which must be removed (i.e., which options vary among the multilibs). This presents a chicken-and-egg problem. GCC developers, in their infinite wisdom, do not allow arbitrary multilib specification to be supplied to GCC's configure. Instead, the target (and sometimes some extra options) determine the set of multilibs - which may include different CPUs, different ABIs, different endianness, different FPUs, different floating-point ABIs, ... That is, we don't know which parts vary until we build GCC and ask it. So, the solution implemented here is: - For multilib builds, start with empty CT_ARCH_TARGET_CFLAGS/LDFLAGS. - For multilib builds, require core pass 1. Pass 1 does not build any target binaries, so at that point, our target options have not been used yet. - Provide an API to modify the environment variables for the steps that follow the current one. - As a part of multilib-related housekeeping, determine the variable part of multilibs and filter out these options; pass the rest into CT_TARGET_CFLAGS/LDFLAGS. This still does not handle extra dependencies between GCC options (like -ma implying -mcpu=X -mtune=Y, etc.) but I feel that would complicate matters too much. Let's leave this until there's a compelling case for it. Also, query GCC's sysroot suffix for targets that use it (SuperH, for example) - the default multilib may not work if the command line specifies the default option explicitly (%sysroot_suffix_spec is not aware of multilib defaults). Signed-off-by: Alexey Neyman <stilor@att.net>
411 lines
11 KiB
Plaintext
411 lines
11 KiB
Plaintext
# Target definition: architecture, optimisations, etc...
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menu "Target options"
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config ARCH
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string
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# Pre-declare target optimisation variables
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config ARCH_SUPPORTS_BOTH_MMU
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config ARCH_SUPPORTS_BOTH_ENDIAN
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config ARCH_SUPPORTS_8
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config ARCH_SUPPORTS_32
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config ARCH_SUPPORTS_64
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config ARCH_SUPPORTS_WITH_ARCH
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config ARCH_SUPPORTS_WITH_ABI
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config ARCH_SUPPORTS_WITH_CPU
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config ARCH_SUPPORTS_WITH_TUNE
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config ARCH_SUPPORTS_WITH_FLOAT
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config ARCH_SUPPORTS_WITH_FPU
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config ARCH_SUPPORTS_SOFTFP
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config ARCH_DEFAULT_HAS_MMU
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config ARCH_DEFAULT_BE
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config ARCH_DEFAULT_LE
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config ARCH_DEFAULT_32
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config ARCH_DEFAULT_64
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config ARCH_ARCH
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config ARCH_ABI
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config ARCH_CPU
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config ARCH_TUNE
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config ARCH_FPU
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config ARCH_BE
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config ARCH_LE
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config ARCH_32
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config ARCH_64
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config ARCH_BITNESS
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config ARCH_FLOAT_HW
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config ARCH_FLOAT_SW
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config TARGET_CFLAGS
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config TARGET_LDFLAGS
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source "config.gen/arch.in"
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config ARCH_SUFFIX
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string
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prompt "Suffix to the arch-part"
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help
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Some architectures have multiple variants and being able to specify
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the variant instead of the arch is quite convenient. This is commonly
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seen for instance when "armv5tel-" is used as a prefix instead of the
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more generic "arm-", or with "alphaev6-" instead of "alpha-".
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Whatever you enter here will be appended to the architecture-part of the
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tuple, just before the first '-'. It will override any architecture-
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specific suffix that crosstool-NG may compute.
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If you are not sure about what this is, leave it blank.
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#--------------------------------------
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comment "Generic target options"
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#--------------------------------------
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config ARCH_REQUIRES_MULTILIB
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bool
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select MULTILIB
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# Multilib requires 1st core pass (i.e., pass without building libgcc)
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# to determine which target cflags vary with multilib and which must be
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# passed from the arch configuration.
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config MULTILIB
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bool
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prompt "Build a multilib toolchain (READ HELP!!!)"
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select CC_CORE_PASS_1_NEEDED
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help
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If you say 'y' here, then the toolchain will also contain the C library
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optimised for some variants of the selected architecture, besides the
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default settings.
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This means the build time of the C library will be in O(nb_variants).
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The list of variants is dependent on the architecture, and is hard-coded
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in gcc, so it is not possible to say what variants to support, only
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whether hard-coded variants should be supported or not.
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NOTE: The multilib feature in crosstool-NG is not well-tested.
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Use at your own risk, and report success and/or failure.
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#--------------------------------------
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config ARCH_SUPPORTS_BOTH_MMU
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bool
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config ARCH_DEFAULT_HAS_MMU
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bool
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config ARCH_USE_MMU
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bool
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prompt "Use the MMU" if ARCH_SUPPORTS_BOTH_MMU
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default y if ARCH_DEFAULT_HAS_MMU
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help
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If your architecture has an MMU and you want to use it,
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say 'Y' here.
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OTOH, if you don't want to use the MMU, or your arch
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lacks an MMU, say 'N' here.
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Note that some architectures (eg. ARM) has variants that
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lacks an MMU (eg. ARM Cortex-M3), while other variants
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have one (eg. ARM Cortex-A8).
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#--------------------------------------
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config ARCH_SUPPORTS_BOTH_ENDIAN
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bool
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config ARCH_DEFAULT_BE
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bool
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config ARCH_DEFAULT_LE
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bool
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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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default ARCH_BE if ARCH_DEFAULT_BE
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default ARCH_LE if ARCH_DEFAULT_LE
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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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config ARCH_ENDIAN
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string
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depends on ARCH_SUPPORTS_BOTH_ENDIAN
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default "big" if ARCH_BE
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default "little" if ARCH_LE
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#--------------------------------------
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config ARCH_SUPPORTS_8
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bool
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config ARCH_SUPPORTS_32
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bool
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config ARCH_SUPPORTS_64
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bool
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config ARCH_DEFAULT_8
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bool
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config ARCH_DEFAULT_32
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bool
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config ARCH_DEFAULT_64
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bool
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config ARCH_BITNESS
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int
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default "8" if ARCH_8
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default "32" if ARCH_32
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default "64" if ARCH_64
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choice
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bool
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prompt "Bitness:"
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default ARCH_8 if ARCH_DEFAULT_8
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default ARCH_32 if ARCH_DEFAULT_32
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default ARCH_64 if ARCH_DEFAULT_64
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config ARCH_8
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bool
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prompt "8-bit"
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depends on ARCH_SUPPORTS_8
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config ARCH_32
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bool
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prompt "32-bit"
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depends on ARCH_SUPPORTS_32
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config ARCH_64
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bool
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prompt "64-bit"
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depends on ARCH_SUPPORTS_64
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endchoice
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#--------------------------------------
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comment "Target optimisations"
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config ARCH_SUPPORTS_WITH_ARCH
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bool
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config ARCH_SUPPORTS_WITH_ABI
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bool
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config ARCH_SUPPORTS_WITH_CPU
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bool
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config ARCH_SUPPORTS_WITH_TUNE
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bool
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config ARCH_SUPPORTS_WITH_FLOAT
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bool
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config ARCH_SUPPORTS_WITH_FPU
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bool
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config ARCH_SUPPORTS_SOFTFP
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bool
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config ARCH_EXCLUSIVE_WITH_CPU
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bool
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config ARCH_ARCH
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string
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prompt "Architecture level"
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depends on ARCH_SUPPORTS_WITH_ARCH
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depends on !ARCH_EXCLUSIVE_WITH_CPU || ARCH_CPU = ""
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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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depends on ARCH_SUPPORTS_WITH_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 architecture 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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depends on ARCH_SUPPORTS_WITH_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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depends on ARCH_SUPPORTS_WITH_TUNE
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depends on !ARCH_EXCLUSIVE_WITH_CPU || ARCH_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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depends on ARCH_SUPPORTS_WITH_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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depends on ARCH_SUPPORTS_WITH_FLOAT
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config ARCH_FLOAT_AUTO
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bool
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prompt "auto (let gcc decide)"
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help
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Instead of explicitly passing a float option, don't
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pass any float options and let gcc figure it out.
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For multilib configurations, this may help.
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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_SOFTFP
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bool
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prompt "softfp (FPU)"
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depends on ARCH_SUPPORTS_SOFTFP
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help
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Emit hardware floating point opcodes but use the software
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floating point calling convention.
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Architectures such as ARM use different registers for passing
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floating point values depending on if they're in software mode
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or hardware mode. softfp emits FPU instructions but uses the
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software FP calling convention allowing softfp code to
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interoperate with legacy software only code.
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If in doubt, use 'software' or 'hardware' mode instead.
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config ARCH_FLOAT_SW
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bool
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prompt "software (no FPU)"
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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 ARCH, ABI, CPU, TUNE and FPU will be
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automatically 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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config TARGET_LDFLAGS
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string
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prompt "Target LDFLAGS"
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default ""
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help
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Used to add specific options when linking libraries of the toolchain,
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that will run on your target.
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Leave blank if you don't know better.
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config ARCH_FLOAT
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string
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default "" if ! ARCH_SUPPORTS_WITH_FLOAT
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default "auto" if ARCH_FLOAT_AUTO
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default "hard" if ARCH_FLOAT_HW
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default "soft" if ARCH_FLOAT_SW
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default "softfp" if ARCH_FLOAT_SOFTFP
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source "config.gen/arch.in.2"
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endmenu
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