Mathieu Malaterre <ma...@debian.org> writes: > On Tue, Jul 10, 2018 at 3:47 PM Michael Ellerman <m...@ellerman.id.au> wrote: >> Mathieu Malaterre <ma...@debian.org> writes: >> > On Mon, Jul 9, 2018 at 4:24 PM Michael Ellerman <m...@ellerman.id.au> >> > wrote: >> >> Because the allmodconfig logic just sets every symbol to M or Y, it >> >> has the effect of always generating a 64-bit config, because >> >> CONFIG_PPC64 becomes Y. >> >> >> >> So to make it easier for folks to test 32-bit code, provide a phony >> >> defconfig target that generates a 32-bit allmodconfig. >> >> >> >> The 32-bit port has several mutually exclusive CPU types, we choose >> >> the Book3S variants as that's what the help text in Kconfig says is >> >> most common. >> > >> > Ok then. >> >> That was just me taking a stab in the dark. You suggested we should >> mimic the Debian config, what does that use? > > Sorry got confused for a minute. This is the correct value (at least > the one used in Debian).
OK cool. >> >> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile >> >> index 2ea575cb3401..2556c2182789 100644 >> >> --- a/arch/powerpc/Makefile >> >> +++ b/arch/powerpc/Makefile >> >> @@ -354,6 +354,11 @@ mpc86xx_smp_defconfig: >> >> $(call merge_into_defconfig,mpc86xx_basic_defconfig,\ >> >> 86xx-smp 86xx-hw fsl-emb-nonhw) >> >> >> >> +PHONY += ppc32_allmodconfig >> >> +ppc32_allmodconfig: >> >> + $(Q)$(MAKE) >> >> KCONFIG_ALLCONFIG=$(srctree)/arch/powerpc/configs/book3s_32.config \ >> >> + -f $(srctree)/Makefile allmodconfig >> >> + >> > >> > I this a good time to update line 34 at the same time: >> > >> > KBUILD_DEFCONFIG := $(shell uname -m)_defconfig >> > >> > ? >> >> 34 or 36? >> >> ifeq ($(CROSS_COMPILE),) >> KBUILD_DEFCONFIG := $(shell uname -m)_defconfig >> else >> KBUILD_DEFCONFIG := ppc64_defconfig >> endif >> >> Do you mean the else case? > > As far as I know uname -m on powerpc returns 'ppc' so the following > has always failed from a ppc32be machine: Oh yep it does. I've never built a kernel *on* a 32-bit machine ;) > $ make ARCH=powerpc defconfig > > I was simply suggesting to mimic what was done for ppc64: > > ifeq ($(CROSS_COMPILE),) > KBUILD_DEFCONFIG := ppc32_defconfig > else > KBUILD_DEFCONFIG := ppc64_defconfig > endif That wouldn't work, CROSS_COMPILE isn't a ppc/ppc64 thing. In fact setting CROSS_COMPILE doesn't actually mean you're cross compiling, it just means you're using a different toolchain. I do that all the time, because I want to use a specific version of GCC, not the distro one. What about: diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 2ea575c..e70d223 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -30,10 +30,13 @@ endif endif endif -ifeq ($(CROSS_COMPILE),) -KBUILD_DEFCONFIG := $(shell uname -m)_defconfig +host_arch := $(shell uname -m) +ifeq ($(host_arch),ppc) + KBUILD_DEFCONFIG := ppc32_defconfig +else ifeq ($(host_arch),ppc64) + KBUILD_DEFCONFIG := ppc64_defconfig else -KBUILD_DEFCONFIG := ppc64_defconfig + KBUILD_DEFCONFIG := ppc64le_defconfig endif ifeq ($(CONFIG_PPC64),y) We obviously need a ppc32_defconfig to make that work. > If I followed the discussion one would want the file `ppc32_defconfig` > to contains pretty much the same thing as the .config generated from > `book3s_32.config`, right ? Can you boot the resulting kernel if you build ppc32_allmodconfig ? Maybe we should just make that be ppc32_defconfig. cheers
