Eric Lee / smarc-fsl-linux-kernel

21 May, 2019

1 commit

22 Feb, 2018

1 commit

  • 7ed1c1901   tools: fix cross-compile var clobbering ... Browse Code »

    Currently a number of Makefiles break when used with toolchains that
    pass extra flags in CC and other cross-compile related variables (such
    as --sysroot).

    Thus we get this error when we use a toolchain that puts --sysroot in
    the CC var:

    ~/src/linux/tools$ make iio
    [snip]
    iio_event_monitor.c:18:10: fatal error: unistd.h: No such file or directory
    #include
    ^~~~~~~~~~

    This occurs because we clobber several env vars related to
    cross-compiling with lines like this:

    CC = $(CROSS_COMPILE)gcc

    Although this will point to a valid cross-compiler, we lose any extra
    flags that might exist in the CC variable, which can break toolchains
    that rely on them (for example, those that use --sysroot).

    This easily shows up using a Yocto SDK:

    $ . [snip]/sdk/environment-setup-cortexa8hf-neon-poky-linux-gnueabi

    $ echo $CC
    arm-poky-linux-gnueabi-gcc -march=armv7-a -mfpu=neon -mfloat-abi=hard
    -mcpu=cortex-a8
    --sysroot=[snip]/sdk/sysroots/cortexa8hf-neon-poky-linux-gnueabi

    $ echo $CROSS_COMPILE
    arm-poky-linux-gnueabi-

    $ echo ${CROSS_COMPILE}gcc
    krm-poky-linux-gnueabi-gcc

    Although arm-poky-linux-gnueabi-gcc is a cross-compiler, we've lost the
    --sysroot and other flags that enable us to find the right libraries to
    link against, so we can't find unistd.h and other libraries and headers.
    Normally with the --sysroot flag we would find unistd.h in the sdk
    directory in the sysroot:

    $ find [snip]/sdk/sysroots -path '*/usr/include/unistd.h'
    [snip]/sdk/sysroots/cortexa8hf-neon-poky-linux-gnueabi/usr/include/unistd.h

    The perf Makefile adds CC = $(CROSS_COMPILE)gcc if and only if CC is not
    already set, and it compiles correctly with the above toolchain.

    So, generalize the logic that perf uses in the common Makefile and
    remove the manual CC = $(CROSS_COMPILE)gcc lines from each Makefile.

    Note that this patch does not fix cross-compile for all the tools (some
    have other bugs), but it does fix it for all except usb and acpi, which
    still have other unrelated issues.

    I tested both with and without the patch on native and cross-build and
    there appear to be no regressions.

    Link: http://lkml.kernel.org/r/20180107214028.23771-1-martin@martingkelly.com
    Signed-off-by: Martin Kelly
    Acked-by: Mark Brown
    Cc: Tejun Heo
    Cc: Li Zefan
    Cc: Johannes Weiner
    Cc: Linus Walleij
    Cc: "K. Y. Srinivasan"
    Cc: Haiyang Zhang
    Cc: Stephen Hemminger
    Cc: Jonathan Cameron
    Cc: Pali Rohar
    Cc: Richard Purdie
    Cc: Jacek Anaszewski
    Cc: Pavel Machek
    Cc: Peter Zijlstra
    Cc: Ingo Molnar
    Cc: Arnaldo Carvalho de Melo
    Cc: Robert Moore
    Cc: Lv Zheng
    Cc: "Rafael J. Wysocki"
    Cc: Greg Kroah-Hartman
    Cc: Valentina Manea
    Cc: Shuah Khan
    Cc: Mario Limonciello
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Martin Kelly
     

04 Nov, 2017

1 commit