5 files changed, 42 insertions, 0 deletions
diff --git a/src/kernel/tests/main.c b/src/kernel/tests/main.c
index a7e9534..41ebe8d 100644
--- a/src/kernel/tests/main.c
+++ b/src/kernel/tests/main.c
@@ -13,6 +13,7 @@ void tests_all() {
 	_did_tests_fail = false;
 
 	TEST_RUN(basic_math);
+	tests_utils();
 
 	if (_did_tests_fail)
 		panic();
diff --git a/src/kernel/tests/tests.h b/src/kernel/tests/tests.h
index d9abce4..78397da 100644
--- a/src/kernel/tests/tests.h
+++ b/src/kernel/tests/tests.h
@@ -1,3 +1,5 @@
 #pragma once
 
 void tests_all();
+
+void tests_utils();
diff --git a/src/kernel/tests/util.c b/src/kernel/tests/util.c
new file mode 100644
index 0000000..5bc8656
--- /dev/null
+++ b/src/kernel/tests/util.c
@@ -0,0 +1,26 @@
+#include <kernel/tests/base.h>
+#include <kernel/util.h>
+
+TEST(memcmp) {
+	// basic equality checks
+	TEST_IF(0 == memcmp("some", "thing", 0))
+	TEST_IF(0 != memcmp("some", "thing", 1))
+	TEST_IF(0 != memcmp("some", "thing", 4))
+
+	TEST_IF(0 == memcmp("test", "tennis",  0));
+	TEST_IF(0 == memcmp("test", "tennis",  1));
+	TEST_IF(0 == memcmp("test", "tennis",  2));
+	TEST_IF(0 != memcmp("test", "tennis",  3));
+	TEST_IF(0 != memcmp("test", "tennis",  4));
+	TEST_IF(0 != memcmp("test", "tennis",  5));
+
+	// test signs. does anyone even use that?
+	TEST_IF(0 > memcmp("foo", "moo", 4));
+	TEST_IF(0 < memcmp("moo", "foo", 4));
+	TEST_IF(0 > memcmp("555", "654", 3));
+	TEST_IF(0 < memcmp("654", "555", 3));
+}
+
+void tests_utils() {
+	TEST_RUN(memcmp);
+}
diff --git a/src/kernel/util.c b/src/kernel/util.c
index f4dc5e1..0977745 100644
--- a/src/kernel/util.c
+++ b/src/kernel/util.c
@@ -15,3 +15,14 @@ void *memset(void *s, int c, size_t n) {
 		s2[i] = c;
 	return s;
 }
+
+int memcmp(const void *s1, const void *s2, size_t n) {
+	const unsigned char *c1 = s1, *c2 = s2;
+	for (size_t i = 0; i < n; i++) {
+		if (c1[i] != c2[i]) {
+			if (c1[i] < c2[i])  return -1;
+			else                return 1;
+		}
+	}
+	return 0;
+}
diff --git a/src/kernel/util.h b/src/kernel/util.h
index 39301d6..b50810d 100644
--- a/src/kernel/util.h
+++ b/src/kernel/util.h
@@ -6,3 +6,5 @@
 
 void *memcpy(void *dest, const void *src, size_t n);
 void *memset(void *s, int c, size_t n);
+
+int memcmp(const void *s1, const void *s2, size_t n);