将支持的中断个数从32个扩展到160个，至此可以支持所有中断

bsp/ls1cdev/libraries/ls1c_public.c

@@ -77,3 +77,41 @@ unsigned int reg_read_32(volatile unsigned int *addr)
 
 
 
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ *
+ * This is defined the same way as
+ * the libc and compiler builtin ffs routines, therefore
+ * differs in spirit from the above ffz (man ffs).
+ */
+int ls1c_ffs(int x)
+{
+	int r = 1;
+
+	if (!x)
+		return 0;
+	if (!(x & 0xffff)) {
+		x >>= 16;
+		r += 16;
+	}
+	if (!(x & 0xff)) {
+		x >>= 8;
+		r += 8;
+	}
+	if (!(x & 0xf)) {
+		x >>= 4;
+		r += 4;
+	}
+	if (!(x & 3)) {
+		x >>= 2;
+		r += 2;
+	}
+	if (!(x & 1)) {
+		x >>= 1;
+		r += 1;
+	}
+	return r;
+}
+
+

bsp/ls1cdev/libraries/ls1c_public.h

@@ -73,6 +73,12 @@ void reg_write_32(unsigned int data, volatile unsigned int *addr);
 unsigned int reg_read_32(volatile unsigned int *addr);
 
 
+/**
+ * ffs - find first bit set
+ * @x: the word to search
+ */
+int ls1c_ffs(int x);
+
 
 #endif