libs/libc: fixed armv7-m strcmp build issue

Signed-off-by: zhangyuan21 <[email protected]>

Author: zhangyuan21

libs/libc/machine/arm/armv7-m/gnu/arch_strcmp.S

@@ -34,6 +34,28 @@
 
 #include "arm_asm.h"
 
+#ifdef __ARM_BIG_ENDIAN
+#define S2LO lsl
+#define S2LOEQ lsleq
+#define S2HI lsr
+#define MSB 0x000000ff
+#define LSB 0xff000000
+#define BYTE0_OFFSET 24
+#define BYTE1_OFFSET 16
+#define BYTE2_OFFSET 8
+#define BYTE3_OFFSET 0
+#else /* not  __ARM_BIG_ENDIAN */
+#define S2LO lsr
+#define S2LOEQ lsreq
+#define S2HI lsl
+#define BYTE0_OFFSET 0
+#define BYTE1_OFFSET 8
+#define BYTE2_OFFSET 16
+#define BYTE3_OFFSET 24
+#define MSB 0xff000000
+#define LSB 0x000000ff
+#endif /* not  __ARM_BIG_ENDIAN */
+
 /* Parameters and result.  */
 #define src1		r0
 #define src2		r1
@@ -46,6 +68,14 @@
 #define tmp1		r12
 #define syndrome	r12	/* Overlaps tmp1 */
 
+	.macro def_fn f p2align=0
+	.text
+	.p2align \p2align
+	.global \f
+	.type \f, %function
+\f:
+	.endm
+
 	.thumb
 	.syntax unified
 def_fn strcmp