Define PXE types in terms of other PXE types where possible

src/include/pxe_types.h

 
 /** @defgroup pxe_types PXE data types
  *
- * Basic PXE data types such as #UINT16, #ADDR32, #SEGSEL etc.
+ * Basic PXE data types such as #UINT16_t, #ADDR32_t, #SEGSEL_t etc.
  *
  * These definitions are based on Table 1-1 ("Data Type Definitions")
  * in the Intel PXE specification version 2.1.  They have been
  * Permitted values are #PXENV_EXIT_SUCCESS and #PXENV_EXIT_FAILURE.
  *
  */
-typedef uint16_t PXENV_EXIT_t;
+typedef UINT16_t PXENV_EXIT_t;
 #define PXENV_EXIT_SUCCESS	0x0000	/**< No error occurred */
 #define PXENV_EXIT_FAILURE	0x0001	/**< An error occurred */
 
  * Status codes are defined in errno.h.
  *
  */
-typedef uint16_t PXENV_STATUS_t;
+typedef UINT16_t PXENV_STATUS_t;
 
 /** An IP address.
  *
  * This is an IPv4 address in host byte order.
  *
  */
-typedef uint32_t IP4_t;
+typedef UINT32_t IP4_t;
 
 /** A UDP port.
  *
  * @note This data type is in network (big-endian) byte order.
  *
  */
-typedef uint16_t UDP_PORT_t;
+typedef UINT16_t UDP_PORT_t;
 
 /** Maximum length of a MAC address */
 #define MAC_ADDR_LEN 16
 
 /** A MAC address */
-typedef uint8_t MAC_ADDR_t[MAC_ADDR_LEN];
+typedef UINT8_t MAC_ADDR_t[MAC_ADDR_LEN];
 
+#ifndef HAVE_ARCH_ADDR32
 /** A physical address.
  *
  * For x86, this is a 32-bit physical address, and is therefore
  * limited to the low 4GB.
  *
  */
-typedef physaddr_t ADDR32_t;
+typedef UINT32_t ADDR32_t;
+#endif
 
 #ifndef HAVE_ARCH_SEGSEL
 /** A segment selector.
  * segment register.
  *
  */
-typedef uint16_t SEGSEL_t;
+typedef UINT16_t SEGSEL_t;
 #endif
 
 #ifndef HAVE_ARCH_OFF16
-/** An offset within a segment identified by #SEGSEL */
-typedef uint16_t OFF16_t;
+/** An offset within a segment identified by #SEGSEL
+ *
+ * For x86, this is a 16-bit offset.
+ *
+ */
+typedef UINT16_t OFF16_t;
 #endif
 
-/** A segment:offset address */
+/** A segment:offset address
+ *
+ * For x86, this is a 16-bit real-mode or protected-mode
+ * segment:offset address.
+ *
+ */
 typedef struct s_SEGOFF16 {
 	OFF16_t		offset;		/**< Offset within the segment */
 	SEGSEL_t	segment;	/**< Segment selector */