[POWERPC] Add memchr() to the bootwrapper

This adds a memchr() implementation to the bootwrapper, which will
be needed when libfdt is merged in.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/boot/string.S

@@ -219,6 +219,19 @@ backwards_memcpy:
 	mtctr	r7
 	b	1b
 
+	.globl	memchr
+memchr:
+	cmpwi	0,r5,0
+	blelr
+	mtctr	r5
+	addi	r3,r3,-1
+1:	lbzu	r0,1(r3)
+	cmpw	r0,r4
+	beqlr
+	bdnz	1b
+	li	r3,0
+	blr
+
 	.globl	memcmp
 memcmp:
 	cmpwi	0,r5,0

arch/powerpc/boot/string.h

@@ -14,6 +14,7 @@ extern size_t strnlen(const char *s, size_t count);
 extern void *memset(void *s, int c, size_t n);
 extern void *memmove(void *dest, const void *src, unsigned long n);
 extern void *memcpy(void *dest, const void *src, unsigned long n);
+extern void *memchr(const void *s, int c, size_t n);
 extern int memcmp(const void *s1, const void *s2, size_t n);
 
 #endif	/* _PPC_BOOT_STRING_H_ */