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    ARM: pass -marm to gcc by default for both C and assembler · 91802a8e
    Arnd Bergmann 提交于
    The Linaro cross toolchain and probably others nowadays default to
    building in THUMB2 mode. When building a kernel for a CPU that does
    not support THUMB2, the compiler complains about incorrect flags.
    We can work around this by setting -marm for all non-T2 builds.
    
    -marm was passed unconditionally for C files previously, but nothing was
    passed to the gcc frontend when processing .S files, resulting in a
    warning.  The assembler never defaults to ARM unless -Wa,-mthumb is
    supplied explicitly, so the files were still assembled correctly.
    
    This patch makes sure that -marm is passed for .S files too, and also
    avoids the redundant gcc -marm -mthumb in Thumb kernels.
    
    Without this patch, building assabet_defconfig results in:
    
    usr/initramfs_data.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default]
    arch/arm/nwfpe/entry.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default]
    firmware/cis/PCMLM28.cis.gen.S:1:0: warning: target CPU does not support THUMB instructions [enabled by default]
    (and many more)
    Signed-off-by: NArnd Bergmann <arnd@arndb.de>
    Acked-by: NNicolas Pitre <nico@linaro.org>
    Acked-by: NDave Martin <dave.martin@linaro.org>
    Cc: Russell King <rmk+kernel@arm.linux.org.uk>
    91802a8e
Makefile 11.2 KB