diff --git a/usr.sbin/bhyve/basl.h b/usr.sbin/bhyve/basl.h
--- a/usr.sbin/bhyve/basl.h
+++ b/usr.sbin/bhyve/basl.h
@@ -42,6 +42,13 @@
 
 int basl_finish(void);
 int basl_init(void);
+int basl_table_add_checksum(struct basl_table *const table, const uint32_t off,
+    const uint32_t start, const uint32_t len);
+int basl_table_add_length(struct basl_table *const table, const uint32_t off,
+    const uint8_t size);
+int basl_table_add_pointer(struct basl_table *const table,
+    const uint8_t src_signature[ACPI_NAMESEG_SIZE], const uint32_t off,
+    const uint8_t size);
 int basl_table_append_bytes(struct basl_table *table, const void *bytes,
     uint32_t len);
 int basl_table_append_checksum(struct basl_table *table, uint32_t start,
diff --git a/usr.sbin/bhyve/basl.c b/usr.sbin/bhyve/basl.c
--- a/usr.sbin/bhyve/basl.c
+++ b/usr.sbin/bhyve/basl.c
@@ -322,12 +322,14 @@
 	return (0);
 }
 
-static int
+int
 basl_table_add_checksum(struct basl_table *const table, const uint32_t off,
     const uint32_t start, const uint32_t len)
 {
 	struct basl_table_checksum *checksum;
 
+	assert(table != NULL);
+
 	checksum = calloc(1, sizeof(struct basl_table_checksum));
 	if (checksum == NULL) {
 		warnx("%s: failed to allocate checksum", __func__);
@@ -343,12 +345,15 @@
 	return (0);
 }
 
-static int
+int
 basl_table_add_length(struct basl_table *const table, const uint32_t off,
     const uint8_t size)
 {
 	struct basl_table_length *length;
 
+	assert(table != NULL);
+	assert(size == 4 || size == 8);
+
 	length = calloc(1, sizeof(struct basl_table_length));
 	if (length == NULL) {
 		warnx("%s: failed to allocate length", __func__);
@@ -363,13 +368,16 @@
 	return (0);
 }
 
-static int
+int
 basl_table_add_pointer(struct basl_table *const table,
     const uint8_t src_signature[ACPI_NAMESEG_SIZE], const uint32_t off,
     const uint8_t size)
 {
 	struct basl_table_pointer *pointer;
 
+	assert(table != NULL);
+	assert(size == 4 || size == 8);
+
 	pointer = calloc(1, sizeof(struct basl_table_pointer));
 	if (pointer == NULL) {
 		warnx("%s: failed to allocate pointer", __func__);