ARM: zImage: gather some string functions into string.c
This is a small subset of string functions needed by commits to come.
Except for memcpy() which is unchanged from its original location, their
implementation is meant to be small, and -Os is enforced to prevent gcc
from doing pointless loop unrolling.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Dave Martin <dave.martin@linaro.org>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
diff --git a/arch/arm/boot/compressed/string.c b/arch/arm/boot/compressed/string.c
new file mode 100644
index 0000000..36e53ef
--- /dev/null
+++ b/arch/arm/boot/compressed/string.c
@@ -0,0 +1,127 @@
+/*
+ * arch/arm/boot/compressed/string.c
+ *
+ * Small subset of simple string routines
+ */
+
+#include <linux/string.h>
+
+void *memcpy(void *__dest, __const void *__src, size_t __n)
+{
+ int i = 0;
+ unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
+
+ for (i = __n >> 3; i > 0; i--) {
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ }
+
+ if (__n & 1 << 2) {
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ *d++ = *s++;
+ }
+
+ if (__n & 1 << 1) {
+ *d++ = *s++;
+ *d++ = *s++;
+ }
+
+ if (__n & 1)
+ *d++ = *s++;
+
+ return __dest;
+}
+
+void *memmove(void *__dest, __const void *__src, size_t count)
+{
+ unsigned char *d = __dest;
+ const unsigned char *s = __src;
+
+ if (__dest == __src)
+ return __dest;
+
+ if (__dest < __src)
+ return memcpy(__dest, __src, count);
+
+ while (count--)
+ d[count] = s[count];
+ return __dest;
+}
+
+size_t strlen(const char *s)
+{
+ const char *sc = s;
+
+ while (*sc != '\0')
+ sc++;
+ return sc - s;
+}
+
+int memcmp(const void *cs, const void *ct, size_t count)
+{
+ const unsigned char *su1 = cs, *su2 = ct, *end = su1 + count;
+ int res = 0;
+
+ while (su1 < end) {
+ res = *su1++ - *su2++;
+ if (res)
+ break;
+ }
+ return res;
+}
+
+int strcmp(const char *cs, const char *ct)
+{
+ unsigned char c1, c2;
+ int res = 0;
+
+ do {
+ c1 = *cs++;
+ c2 = *ct++;
+ res = c1 - c2;
+ if (res)
+ break;
+ } while (c1);
+ return res;
+}
+
+void *memchr(const void *s, int c, size_t count)
+{
+ const unsigned char *p = s;
+
+ while (count--)
+ if ((unsigned char)c == *p++)
+ return (void *)(p - 1);
+ return NULL;
+}
+
+char *strchr(const char *s, int c)
+{
+ while (*s != (char)c)
+ if (*s++ == '\0')
+ return NULL;
+ return (char *)s;
+}
+
+#undef memset
+
+void *memset(void *s, int c, size_t count)
+{
+ char *xs = s;
+ while (count--)
+ *xs++ = c;
+ return s;
+}
+
+void __memzero(void *s, size_t count)
+{
+ memset(s, 0, count);
+}