Index: uspace/lib/scsi/include/scsi/spc.h
===================================================================
--- uspace/lib/scsi/include/scsi/spc.h	(revision dd8b6a87925c4db039bcd5d96da488ee67d92e29)
+++ uspace/lib/scsi/include/scsi/spc.h	(revision d2e66bf4c0ccc1c3b2ddbb1809e927894792db2c)
@@ -42,6 +42,7 @@
 /** SCSI command codes defined in SCSI-SPC */
 enum scsi_cmd_spc {
-	SCSI_CMD_INQUIRY	= 0x12,
-	SCSI_CMD_REQUEST_SENSE	= 0x03
+	SCSI_CMD_TEST_UNIT_READY = 0x00,
+	SCSI_CMD_REQUEST_SENSE	 = 0x03,
+	SCSI_CMD_INQUIRY	 = 0x12,
 };
 
@@ -220,4 +221,14 @@
 extern const char *scsi_get_sense_key_str(unsigned);
 
+/** SCSI Test Unit Ready command */
+typedef struct {
+	/** Operation code (SCSI_CMD_TEST_UNIT_READY) */
+	uint8_t op_code;
+	/** Reserved */
+	uint32_t reserved;
+	/* Control */
+	uint8_t control;
+} __attribute__((packed)) scsi_cdb_test_unit_ready_t;
+
 #endif