• Vineet Gupta's avatar
    ARC: [kbuild] Avoid DTB rebuilds if DTS are untouched · a89516b3
    Vineet Gupta authored
    Currently, for every ARC kernel build I see the following:
    
    --------------->8-----------------
      DTB    arch/arc/boot/dts/angel4.dtb.S
      AS      arch/arc/boot/dts/angel4.dtb.o
      LD      arch/arc/boot/dts/built-in.o
    rm arch/arc/boot/dts/angel4.dtb.S        <-- forces rebuild next iter
      CHK     kernel/config_data.h
    --------------->8-----------------
    
    This is because *.dts.S is intermediate file in dtb generation and is by
    default deleted by make which needs a ".SECONDARY" hint to NOT do so.
    
    This could have ideally been done in scripts/Makefile.lib - for benefit
    of all, however .SECONDARY doesn't seem to work with wildcards.
    
    Thanks to Stephen for suggesting .SECONDARY (vs .PRECIOUS) and making
    that work using a non wildcard version in arch makefile.
    
    Thanks to James Hogan for pointing out that *.dtb.S now needs to be
    added to clean-files
    Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
    Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
    a89516b3
Makefile 343 Bytes