[PATCH] ppc: force target cpu

[Mark Cave-Ayland]

With gcc-5.2 default target is power7.

- For 32-bit PPC builds set the target cpu to 604 in order to support PReP as
  well as Macs in the future.

- For 64-bit PPC builds set the target cpu to 970 as used in 64-bit Macs but
  disable altivec.

Based on an original patch by Laurent Vivier .

Signed-off-by: Mark Cave-Ayland 
---
 openbios-devel/config/scripts/switch-arch |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/openbios-devel/config/scripts/switch-arch b/openbios-devel/config/scripts/switch-arch
index 38d263d..ab3b4ce 100755
--- a/openbios-devel/config/scripts/switch-arch
+++ b/openbios-devel/config/scripts/switch-arch
@@ -265,7 +265,8 @@ for ARCH in $arch_list; do
         ppc)
         select_prefix powerpc powerpc64
         if [ "$unix" = "no" ]; then
-            CFLAGS="-m32 -msoft-float -fno-builtin-bcopy -fno-builtin-log2"
+            # 604 cpu includes support for PReP as well as Mac
+            CFLAGS="-m32 -mcpu=604 -msoft-float -fno-builtin-bcopy -fno-builtin-log2"
             AS_FLAGS="-m32"
         else
             CFLAGS="-fno-builtin"
@@ -275,7 +276,9 @@ for ARCH in $arch_list; do

ppc64)
         select_prefix powerpc64
-        CFLAGS="-Wa,-a64 -m64 -msoft-float -fno-builtin"
+
+        # 970 cpu is used in all 64-bit Macs but disable altivec
+        CFLAGS="-mcpu=970 -mno-altivec -Wa,-a64 -m64 -msoft-float -fno-builtin"
         AS_FLAGS="-Wa,-a64"
         ;;