[Buildroot] Buildroot does not use ccache for compiling Linux kernel?

["Andreas Düring via buildroot" <buildroot@buildroot.org>]

Hello,

I am currently experimenting with building a minimal image for my
Raspberry Pi.

During this process, I realized that ccache, although enabled, is not
used for compiling the Linux kernel. I think this is because of the
recipe in linux/linux.mk:

LINUX_MAKE_FLAGS = \
        HOSTCC="$(HOSTCC) $(subst -I/,-isystem /,$(subst -I /,-isystem /,$(HOST_CFLAGS))) $(HOST_LDFLAGS)" \
        ARCH=$(KERNEL_ARCH) \
        INSTALL_MOD_PATH=$(TARGET_DIR) \
        CROSS_COMPILE="$(TARGET_CROSS)" \
        WERROR=0 \
        REGENERATE_PARSERS=1 \
        DEPMOD=$(HOST_DIR)/sbin/depmod


The linux kernel seems to assemble the compiler using TARGET_CROSS,
e.g.
CC = $(TARGET_CROSS)gcc

As a very crude solution, I changed the corresponding line to
        CROSS_COMPILE="ccache $(TARGET_CROSS)"
but this is probably not the optimal solution. (I didn't carefully
check where else CROSS_COMPILE is used).

If this is a known limitation? Should this be added to the
documentation?
https://buildroot.org/downloads/manual/manual.html#ccache
("This will automatically build ccache and use it for every host and
target compilation.")

With best regards,
Andreas
_______________________________________________
buildroot mailing list
buildroot@buildroot.org
https://lists.buildroot.org/mailman/listinfo/buildroot