Index: kernel/generic/include/ddi/irq.h
===================================================================
--- kernel/generic/include/ddi/irq.h	(revision a71c158ef82122abfeef92f86344709bbad55d17)
+++ kernel/generic/include/ddi/irq.h	(revision 52ff7699c7d3d605dddc5455935a7299bc7cf8ad)
@@ -37,13 +37,29 @@
 
 typedef enum {
+	/** Read 1 byte from the I/O space. */
 	CMD_PIO_READ_8 = 1,
+	/** Read 2 bytes from the I/O space. */
 	CMD_PIO_READ_16,
+	/** Read 4 bytes from the I/O space. */
 	CMD_PIO_READ_32,
+	/** Write 1 byte to the I/O space. */
 	CMD_PIO_WRITE_8,
+	/** Write 2 bytes to the I/O space. */
 	CMD_PIO_WRITE_16,
+	/** Write 4 bytes to the I/O space. */
 	CMD_PIO_WRITE_32,
+	/**
+	 * Perform a bit test on the source argument and store the result into
+	 * the destination argument.
+	 */
 	CMD_BTEST,
+	/**
+	 * Predicate the execution of the following N commands by the boolean
+	 * value of the source argument.
+	 */
 	CMD_PREDICATE,
+	/** Accept the interrupt. */
 	CMD_ACCEPT,
+	/** Decline the interrupt. */
 	CMD_DECLINE,
 	CMD_LAST