On Mon, 24 Sep 2007 09:49:33 +0200
Wolfgang Grandegger [off-list ref] wrote:

The addition of treeboot-walnut.c breaks compilation of Linux-2.6 for 
the lite5200 using the ppc_6xx toolchain of the ELDK 4.1:

   MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x14): Section mismatch: reference to 
.init.text:prom_init (between '__start' and '__after_mmu_off')
WARNING: vmlinux.o(.text+0x28): Section mismatch: reference to 
.init.text:early_init (between '__start' and '__after_mmu_off')
WARNING: vmlinux.o(.text+0x340c): Section mismatch: reference to 
.init.text:machine_init (between 'start_here' and 'set_context')
WARNING: vmlinux.o(.text+0x3414): Section mismatch: reference to 
.init.text:MMU_init (between 'start_here' and 'set_context')
WARNING: vmlinux.o(.text+0x343e): Section mismatch: reference to 
.init.text:start_kernel (between 'start_here' and 'set_context')
WARNING: vmlinux.o(.text+0x3442): Section mismatch: reference to 
.init.text:start_kernel (between 'start_here' and 'set_context')
   GEN     .version
   CHK     include/linux/compile.h
   UPD     include/linux/compile.h
   CC      init/version.o
   LD      init/built-in.o
   LD      vmlinux
   SYSMAP  System.map
   BOOTAS  arch/powerpc/boot/string.o
   BOOTAS  arch/powerpc/boot/crt0.o
   BOOTCC  arch/powerpc/boot/stdio.o
   BOOTCC  arch/powerpc/boot/main.o
   BOOTCC  arch/powerpc/boot/flatdevtree.o
   BOOTCC  arch/powerpc/boot/flatdevtree_misc.o
   BOOTCC  arch/powerpc/boot/ns16550.o
   BOOTCC  arch/powerpc/boot/serial.o
   BOOTCC  arch/powerpc/boot/simple_alloc.o
   BOOTAS  arch/powerpc/boot/div64.o
   BOOTAS  arch/powerpc/boot/util.o
   BOOTCC  arch/powerpc/boot/gunzip_util.o
   BOOTCC  arch/powerpc/boot/elf_util.o
   BOOTCC  arch/powerpc/boot/inffast.o
   BOOTCC  arch/powerpc/boot/inflate.o
   BOOTCC  arch/powerpc/boot/inftrees.o
   BOOTCC  arch/powerpc/boot/devtree.o
   BOOTCC  arch/powerpc/boot/oflib.o
   BOOTCC  arch/powerpc/boot/ofconsole.o
   BOOTCC  arch/powerpc/boot/4xx.o
   BOOTCC  arch/powerpc/boot/ebony.o
   BOOTCC  arch/powerpc/boot/mv64x60.o
   BOOTCC  arch/powerpc/boot/mpsc.o
   BOOTCC  arch/powerpc/boot/mv64x60_i2c.o
   BOOTCC  arch/powerpc/boot/cuboot.o
   BOOTCC  arch/powerpc/boot/bamboo.o
   BOOTAR  arch/powerpc/boot/wrapper.a
   BOOTCC  arch/powerpc/boot/of.o
   BOOTCC  arch/powerpc/boot/cuboot-83xx.o
   BOOTCC  arch/powerpc/boot/cuboot-85xx.o
   BOOTCC  arch/powerpc/boot/holly.o
   BOOTCC  arch/powerpc/boot/cuboot-ebony.o
   BOOTCC  arch/powerpc/boot/treeboot-ebony.o
   BOOTCC  arch/powerpc/boot/prpmc2800.o
   BOOTAS  arch/powerpc/boot/ps3-head.o
   BOOTAS  arch/powerpc/boot/ps3-hvcall.o
   BOOTCC  arch/powerpc/boot/ps3.o
   BOOTCC  arch/powerpc/boot/treeboot-bamboo.o
   BOOTCC  arch/powerpc/boot/cuboot-sequoia.o
   BOOTCC  arch/powerpc/boot/treeboot-walnut.o
{standard input}: Assembler messages:
{standard input}:184: Error: Unrecognized opcode: `mfdcr'
{standard input}:185: Error: Unrecognized opcode: `mfdcr'
{standard input}:186: Error: Unrecognized opcode: `mfdcr'
{standard input}:217: Error: Unrecognized opcode: `mtdcr'
make[1]: *** [arch/powerpc/boot/treeboot-walnut.o] Error 1
make: *** [uImage] Error 2

It looks like the ppc_6xx toolchain does not know the opcode above. I 
wonder why files for other PowerPC sub-archs like 4xx are compiled with 
the wrong compiler. Have I missed something?

No, you haven't missed anything.  I need a one line patch to fix it.
Could you try the patch below to make sure it works for you?

And the WARNING above on "Section mismatch" looks strange as well (still 
present in 2.6.23-rc7).

Those warnings should be gone with Paul's latest tree.  (They will
remain for 2.6.23.)

josh

Pass the correct -mcpu option for treeboot-walnut.o to avoid
unrecognized opcodes.

Signed-off-by: Josh Boyer <redacted>

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index c1582b6..8e6d36b 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile

@@ -33,6 +33,7 @@ BOOTCFLAGS    += -I$(obj) -I$(srctree)/$(obj)
 
 $(obj)/4xx.o: BOOTCFLAGS += -mcpu=440
 $(obj)/ebony.o: BOOTCFLAGS += -mcpu=440
+$(obj)/treeboot-walnut.o: BOOTFLAGS += -mcpu=405
 
 zlib       := inffast.c inflate.c inftrees.c
 zlibheader := inffast.h inffixed.h inflate.h inftrees.h infutil.h