Workaround for "PowerPC-8xx CPU15 errata" (whatever that might be).

Patch by Nye LIU: http://sourceware.org/ml/crossgcc/2009-05/msg00014.html

 -------- diffstat follows --------
 /trunk/patches/eglibc/2_9/100-powerpc-8xx-CPU15-errata.patch |   49    49     0     0 ++++++++++++++++++
 /trunk/scripts/build/libc/eglibc.sh                          |   10     9     1     0 +++-
 2 files changed, 58 insertions(+), 1 deletion(-)

patches/eglibc/2_9/100-powerpc-8xx-CPU15-errata.patch

@@ -0,0 +1,49 @@
+diff -ru eglibc-2_9_orig/sysdeps/powerpc/powerpc32/memset.S eglibc-2_9/sysdeps/powerpc/powerpc32/memset.S
+--- eglibc-2_9_orig/sysdeps/powerpc/powerpc32/memset.S	2007-04-13 08:35:45.000000000 -0700
++++ eglibc-2_9/sysdeps/powerpc/powerpc32/memset.S	2009-05-06 16:52:04.000000000 -0700
+@@ -112,11 +112,13 @@
+ 	clrrwi.	rALIGN, rLEN, 5
+ 	mtcrf	0x01, rLEN	/* 40th instruction from .align */
+ 
++#ifndef BROKEN_PPC_8xx_CPU15
+ /* Check if we can use the special case for clearing memory using dcbz.
+    This requires that we know the correct cache line size for this
+    processor.  Getting the __cache_line_size may require establishing GOT
+    addressability, so branch out of line to set this up.  */
+ 	beq	cr1, L(checklinesize)
++#endif
+ 
+ /* Store blocks of 32-bytes (256-bits) starting on a 32-byte boundary.
+    Can't assume that rCHR is zero or that the cache line size is either
+@@ -158,6 +160,7 @@
+ 	add	rMEMP, rMEMP, rALIGN
+ 	b	L(medium_tail2)	/* 72nd instruction from .align */
+ 
++#ifndef BROKEN_PPC_8xx_CPU15
+ 	.align	5
+ 	nop
+ /* Clear cache lines of memory in 128-byte chunks.
+@@ -191,6 +194,7 @@
+ 	bdnz	L(zloop)
+ 	beqlr	cr5
+ 	b	L(medium_tail2)
++#endif /* ! BROKEN_PPC_8xx_CPU15 */
+ 
+ 	.align	5
+ L(small):
+@@ -248,6 +252,7 @@
+ 	stw	rCHR, -8(rMEMP)
+ 	blr
+ 
++#ifndef BROKEN_PPC_8xx_CPU15
+ L(checklinesize):
+ #ifdef SHARED
+ 	mflr	rTMP
+@@ -329,6 +334,7 @@
+ L(handletail32):
+ 	clrrwi.	rALIGN, rLEN, 5
+ 	b	L(nondcbz)
++#endif /* ! BROKEN_PPC_8xx_CPU15 */
+ 
+ END (BP_SYM (memset))
+ libc_hidden_builtin_def (memset)

scripts/build/libc/eglibc.sh

@@ -266,7 +266,15 @@ do_libc() {
     
     CT_DoLog EXTRA "Building C library"
 
-    CT_DoExecLog ALL make
+    # eglibc build hacks
+    # http://sourceware.org/ml/crossgcc/2008-10/msg00068.html
+    case "${CT_ARCH},${CT_ARCH_CPU}" in
+        powerpc,8??)
+            CT_DoLog DEBUG "Activating support for memset on broken ppc-8xx (CPU15 erratum)"
+            EGLIBC_BUILD_ASFLAGS="-DBROKEN_PPC_8xx_CPU15";;
+    esac
+
+    CT_DoExecLog ALL make ASFLAGS="${EGLIBC_BUILD_ASFLAGS}"
 
     CT_DoLog EXTRA "Installing C library"