Thread (5 messages) flat view 5 messages, 3 authors, 2019-04-21

Re: [PATCH 2/2] powerpc: Fix defconfig choice logic when cross compiling

From: Mathieu Malaterre <hidden>
Date: 2019-02-07 10:21:24
Subsystem: kernel build + files below scripts/ (unless maintained elsewhere), linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Nathan Chancellor, Nicolas Schier, Madhavan Srinivasan, Linus Torvalds

On Thu, Feb 7, 2019 at 6:20 AM Michael Ellerman [off-list ref] wrote:
Our logic for choosing defconfig doesn't work well in some situations.

For example if you're on a ppc64le machine but you specify a non-empty
CROSS_COMPILE, in order to use a non-default toolchain, then defconfig
will give you ppc64_defconfig (big endian):

  $ make CROSS_COMPILE=~/toolchains/gcc-8/bin/powerpc-linux- defconfig
  *** Default configuration is based on 'ppc64_defconfig'

This is because we assume that CROSS_COMPILE being set means we
can't be on a ppc machine and rather than checking we just default to
ppc64_defconfig.

We should just ignore CROSS_COMPILE, instead check the machine with
uname and if it's one of ppc, ppc64 or ppc64le then use that
defconfig. If it's none of those then we fall back to ppc64_defconfig.
How about shamelessly copying x86:
diff --git a/Makefile b/Makefile
index 3142e67d03f1..041616742142 100644
--- a/Makefile
+++ b/Makefile
@@ -351,6 +351,14 @@ ifeq ($(ARCH),sparc64)
        SRCARCH := sparc
 endif

+# Additional ARCH settings for ppc
+ifeq ($(ARCH),ppc64)
+       SRCARCH := powerpc
+endif
+ifeq ($(ARCH),ppc64el)
+       SRCARCH := powerpc
+endif
+
 # Additional ARCH settings for sh
 ifeq ($(ARCH),sh64)
        SRCARCH := sh
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 10bf5dc7cdf0..cbb679fb7162 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -34,10 +34,17 @@ ifdef CONFIG_PPC_BOOK3S_32
 KBUILD_CFLAGS          += -mcpu=powerpc
 endif

-# If we're on a ppc/ppc64/ppc64le machine use that defconfig,
otherwise just use
-# ppc64_defconfig because we have nothing better to go on.
-uname := $(shell uname -m)
-KBUILD_DEFCONFIG := $(if $(filter ppc%,$(uname)),$(uname),ppc64)_defconfig
+# select defconfig based on actual architecture
+ifeq ($(ARCH),powerpc)
+  ifeq ($(shell uname -m),ppc64)
+        KBUILD_DEFCONFIG := ppc64_defconfig
+  else
+        KBUILD_DEFCONFIG := ppc_defconfig
+  endif
+else
+        KBUILD_DEFCONFIG := $(ARCH)_defconfig
+endif
+

 ifdef CONFIG_PPC64
 new_nm := $(shell if $(NM) --help 2>&1 | grep -- '--synthetic' >
/dev/null; then echo y; else echo n; fi)

quoted hunk ↗ jump to hunk
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/Makefile | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 70e6e8119aeb..81563986a30e 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -34,11 +34,10 @@ ifdef CONFIG_PPC_BOOK3S_32
 KBUILD_CFLAGS          += -mcpu=powerpc
 endif

-ifeq ($(CROSS_COMPILE),)
-KBUILD_DEFCONFIG := $(shell uname -m)_defconfig
-else
-KBUILD_DEFCONFIG := ppc64_defconfig
-endif
+# If we're on a ppc/ppc64/ppc64le machine use that defconfig, otherwise just use
+# ppc64_defconfig because we have nothing better to go on.
+uname := $(shell uname -m)
+KBUILD_DEFCONFIG := $(if $(filter ppc%,$(uname)),$(uname),ppc64)_defconfig

 ifdef CONFIG_PPC64
 new_nm := $(shell if $(NM) --help 2>&1 | grep -- '--synthetic' > /dev/null; then echo y; else echo n; fi)
--
2.20.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help