1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/strlen.S b/kernel/strlen.S
new file mode 100644
index 0000000..6185b94
--- /dev/null
+++ b/kernel/strlen.S
@@ -0,0 +1,22 @@
+.globl strlen
+.type strlen, @function
+
+/*
+ * Defined in include/fbos/string.h
+ *
+ *     size_t strlen(const char *str)
+ *
+ * Returns (a0): string length.
+ * Parameter (a0): string to measure.
+ * Clobbers: t0, t1.
+ */
+strlen:
+	mv t1, a0
+1:
+	lbu t0, 0(t1)
+	beqz t0, 2f
+	addi t1, t1, 1
+	j 1b
+2:
+	sub a0, t1, a0
+	ret