Use a common base-memory packet buffer for DHCP construction (as used

by PXE and NBI) and UNDI packets (as used by undinet and UNDI).

src/arch/i386/core/dhcp_basemem.c → src/arch/i386/core/basemem_packet.c

 /**
  * @file
  *
- * DHCP parameter block provided to external programs in base memory
+ * Packet buffer in base memory.  Used by various components which
+ * need to pass packets to and from external real-mode code.
  *
  */
 
-#include <dhcp_basemem.h>
+#include <basemem_packet.h>
 
-#undef dhcp_basemem
-char __data16_array ( dhcp_basemem, [DHCP_BASEMEM_LEN] );
+#undef basemem_packet
+char __data16_array ( basemem_packet, [BASEMEM_PACKET_LEN] );

src/arch/i386/drivers/net/undinet.c

 #include <pic8259.h>
 #include <biosint.h>
 #include <pnpbios.h>
+#include <basemem_packet.h>
 #include <gpxe/iobuf.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/if_ether.h>
  *****************************************************************************
  */
 
-/** Maximum length of a packet transmitted via the UNDI API */
-#define UNDI_IOB_LEN 1514
-
-/** UNDI I/O buffer */
-static char __data16_array ( undinet_iob, [UNDI_IOB_LEN] );
-#define undinet_iob __use_data16 ( undinet_iob )
-
 /** UNDI transmit buffer descriptor */
 static struct s_PXENV_UNDI_TBD __data16 ( undinet_tbd );
 #define undinet_tbd __use_data16 ( undinet_tbd )
 	int rc;
 
 	/* Copy packet to UNDI I/O buffer */
-	if ( len > sizeof ( undinet_iob ) )
-		len = sizeof ( undinet_iob );
-	memcpy ( &undinet_iob, iobuf->data, len );
+	if ( len > sizeof ( basemem_packet ) )
+		len = sizeof ( basemem_packet );
+	memcpy ( &basemem_packet, iobuf->data, len );
 
 	/* Create PXENV_UNDI_TRANSMIT data structure */
 	memset ( &undi_transmit, 0, sizeof ( undi_transmit ) );
 	undinet_tbd.ImmedLength = len;
 	undinet_tbd.Xmit.segment = rm_ds;
 	undinet_tbd.Xmit.offset 
-		= ( ( unsigned ) & __from_data16 ( undinet_iob ) );
+		= ( ( unsigned ) & __from_data16 ( basemem_packet ) );
 
 	/* Issue PXE API call */
 	if ( ( rc = undinet_call ( undinic, PXENV_UNDI_TRANSMIT,

src/arch/i386/image/nbi.c

 #include <realmode.h>
 #include <gateA20.h>
 #include <memsizes.h>
-#include <dhcp_basemem.h>
+#include <basemem_packet.h>
 #include <gpxe/uaccess.h>
 #include <gpxe/segment.h>
 #include <gpxe/shutdown.h>
 		  "=b" ( discard_b )
 		: "D" ( imgheader->execaddr.segoff ),
 		  "S" ( imgheader->location ),
-		  "b" ( __from_data16 ( dhcp_basemem ) )
+		  "b" ( __from_data16 ( basemem_packet ) )
 		: "ecx", "edx", "ebp" );
 
 	gateA20_set();
 		: "D" ( imgheader->execaddr.linear ),
 		  "S" ( ( imgheader->location.segment << 4 ) +
 			imgheader->location.offset ),
-		  "b" ( virt_to_phys ( dhcp_basemem ) ),
+		  "b" ( virt_to_phys ( basemem_packet ) ),
 		  "a" ( virt_to_phys ( &loaderinfo ) )
 		: "ecx", "edx", "ebp", "memory" );
 
 		return -ENODEV;
 	}
 
-	if ( ( rc = create_dhcp_packet ( boot_netdev, DHCPACK,
-					 dhcp_basemem, sizeof ( dhcp_basemem ),
+	if ( ( rc = create_dhcp_packet ( boot_netdev, DHCPACK, basemem_packet,
+					 sizeof ( basemem_packet ),
 					 &dhcppkt ) ) != 0 ) {
 		DBGC ( image, "NBI %p failed to build DHCP packet\n", image );
 		return rc;

src/arch/i386/include/basemem_packet.h

+#ifndef BASEMEM_PACKET_H
+#define BASEMEM_PACKET_H
+
+#include <realmode.h>
+
+/** Maximum length of base memory packet buffer */
+#define BASEMEM_PACKET_LEN 1514
+
+/** Base memory packet buffer */
+extern char __data16_array ( basemem_packet, [BASEMEM_PACKET_LEN] );
+#define basemem_packet __use_data16 ( basemem_packet )
+
+#endif /* BASEMEM_PACKET_H */

src/arch/i386/include/dhcp_basemem.h

-#ifndef DHCP_BASEMEM_H
-#define DHCP_BASEMEM_H
-
-#include <realmode.h>
-
-/** Maximum length of a DHCP data buffer */
-#define DHCP_BASEMEM_LEN 1514
-
-/** DHCP data buffer */
-extern char __data16_array ( dhcp_basemem, [DHCP_BASEMEM_LEN] );
-#define dhcp_basemem __use_data16 ( dhcp_basemem )
-
-#endif /* DHCP_BASEMEM_H */

src/interface/pxe/pxe_preboot.c

 #include <stdlib.h>
 #include <gpxe/uaccess.h>
 #include <gpxe/dhcp.h>
-#include <dhcp_basemem.h>
+#include <basemem_packet.h>
 #include "pxe.h"
 #include "pxe_call.h"
 
 	 */
 	len = get_cached_info->BufferSize;
 	if ( len == 0 ) {
-		len = sizeof ( dhcp_basemem );
+		len = sizeof ( basemem_packet );
 		get_cached_info->Buffer.segment = rm_ds;
 		get_cached_info->Buffer.offset =
-			( unsigned int ) ( & __from_data16 ( dhcp_basemem ) );
+			( unsigned int ) ( & __from_data16 ( basemem_packet ) );
 		get_cached_info->BufferLimit = len;
 	}