[i386] Change semantics of __from_data16 and __from_text16

__from_data16 and __from_text16 now take a pointer to a
.data16/.text16 variable, and return the real-mode offset within the
appropriate segment.  This matches the use case for every occurrence
of these macros, and prevents potential future bugs such as that fixed
in commit d51d80f.  (The bug arose essentially because "&pointer" is
still syntactically valid.)

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

 					   "lcall *%c2\n\t"
 					   "addw $4, %%sp\n\t" )
 			       : "=a" ( exit )
-			       : "a" ( & __from_data16 ( undi_loader ) ),
-			         "p" ( & __from_data16 ( undi_loader_entry ) )
+			       : "a" ( __from_data16 ( &undi_loader ) ),
+			         "p" ( __from_data16 ( &undi_loader_entry ) )
 			       : "ebx", "ecx", "edx", "esi", "edi", "ebp" );
 
 	/* UNDI API calls may rudely change the status of A20 and not

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

 					   "addw $6, %%sp\n\t" )
 			       : "=a" ( exit ), "=b" ( discard_b ),
 			         "=D" ( discard_D )
-			       : "p" ( &__from_data16 ( undinet_entry_point )),
+			       : "p" ( __from_data16 ( &undinet_entry_point )),
 			         "b" ( function ),
-			         "D" ( &__from_data16 ( undinet_params ) )
+			         "D" ( __from_data16 ( &undinet_params ) )
 			       : "ecx", "edx", "esi", "ebp" );
 
 	/* UNDI API calls may rudely change the status of A20 and not
 	if ( rc != 0 ) {
 		SEGOFF16_t rm_params = {
 			.segment = rm_ds,
-			.offset = (intptr_t) &__from_data16 ( undinet_params ),
+			.offset = __from_data16 ( &undinet_params ),
 		};
 
 		DBGC ( undinic, "UNDINIC %p %s failed: %s\n", undinic,
 	/* Create PXENV_UNDI_TRANSMIT data structure */
 	memset ( &undi_transmit, 0, sizeof ( undi_transmit ) );
 	undi_transmit.DestAddr.segment = rm_ds;
-	undi_transmit.DestAddr.offset
-		= ( ( unsigned ) & __from_data16 ( undinet_tbd ) );
+	undi_transmit.DestAddr.offset = __from_data16 ( &undinet_tbd );
 	undi_transmit.TBD.segment = rm_ds;
-	undi_transmit.TBD.offset
-		= ( ( unsigned ) & __from_data16 ( undinet_tbd ) );
+	undi_transmit.TBD.offset = __from_data16 ( &undinet_tbd );
 
 	/* Create PXENV_UNDI_TBD data structure */
 	undinet_tbd.ImmedLength = len;
 	undinet_tbd.Xmit.segment = rm_ds;
-	undinet_tbd.Xmit.offset 
-		= ( ( unsigned ) & __from_data16 ( basemem_packet ) );
+	undinet_tbd.Xmit.offset = __from_data16 ( basemem_packet );
 
 	/* Issue PXE API call */
 	if ( ( rc = undinet_call ( undinic, PXENV_UNDI_TRANSMIT,

src/arch/i386/firmware/pcbios/memmap.c

 					 "=b" ( next ), "=D" ( discard_D ),
 					 "=c" ( discard_c ), "=d" ( discard_d )
 				       : "a" ( 0xe820 ), "b" ( next ),
-					 "D" ( &__from_data16 ( e820buf ) ),
+					 "D" ( __from_data16 ( &e820buf ) ),
 					 "c" ( sizeof ( e820buf ) ),
 					 "d" ( SMAP )
 				       : "memory" );

src/arch/i386/include/libkir.h

 #define __text16_array( variable,array ) variable array
 #define __use_data16( variable ) variable
 #define __use_text16( variable ) variable
-#define __from_data16( variable ) variable
-#define __from_text16( variable ) variable
+#define __from_data16( pointer ) pointer
+#define __from_text16( pointer ) pointer
 
 /* Real-mode data and code segments */
 static inline __attribute__ (( always_inline )) unsigned int _rm_cs ( void ) {

src/arch/i386/include/librm.h

 	( * ( ( typeof ( _text16_ ## variable ) * )			\
 	      & ( text16 [ ( size_t ) & ( _text16_ ## variable ) ] ) ) )
 
-#define __from_data16( variable )					\
-	( * ( ( typeof ( variable ) * )					\
-	      ( ( ( void * ) &(variable) ) - ( ( void * ) data16 ) ) ) )
+#define __from_data16( pointer )					\
+	( ( unsigned int )						\
+	  ( ( ( void * ) (pointer) ) - ( ( void * ) data16 ) ) )
 
-#define __from_text16( variable )					\
-	( * ( ( typeof ( variable ) * )					\
-	      ( ( ( void * ) &(variable) ) - ( ( void * ) text16 ) ) ) )
+#define __from_text16( pointer )					\
+	( ( unsigned int )						\
+	  ( ( ( void * ) (pointer) ) - ( ( void * ) text16 ) ) )
 
 /* Variables in librm.S, present in the normal data segment */
 extern uint16_t __data16 ( rm_cs );

src/arch/i386/interface/pxe/pxe_call.c

 					   "addw $4, %%sp\n\t" )
 			       : "=a" ( rc ), "=b" ( discard_b ),
 			         "=c" ( discard_c )
-			       :  "a" ( & __from_text16 ( ppxe ) ),
-			          "b" ( & __from_text16 ( pxenv ) ),
+			       :  "a" ( __from_text16 ( &ppxe ) ),
+			          "b" ( __from_text16 ( &pxenv ) ),
 			          "c" ( rm_cs )
 			       : "edx", "esi", "edi", "ebp", "memory" );
 

src/interface/pxe/pxe_loader.c

 
 	/* Fill in UNDI loader structure */
 	undi_loader->PXEptr.segment = rm_cs;
-	undi_loader->PXEptr.offset =
-		( ( unsigned ) & __from_text16 ( ppxe ) );
+	undi_loader->PXEptr.offset = __from_text16 ( &ppxe );
 	undi_loader->PXENVptr.segment = rm_cs;
-	undi_loader->PXENVptr.offset =
-		( ( unsigned ) & __from_text16 ( pxenv ) );
+	undi_loader->PXENVptr.offset = __from_text16 ( &pxenv );
 
 	undi_loader->Status = PXENV_STATUS_SUCCESS;
 	return PXENV_EXIT_SUCCESS;

src/interface/pxe/pxe_preboot.c

 		 * fill it in.
 		 */
 		get_cached_info->Buffer.segment = rm_ds;
-		get_cached_info->Buffer.offset =
-			( unsigned ) ( & __from_data16 ( *info ) );
+		get_cached_info->Buffer.offset = __from_data16 ( info );
 		get_cached_info->BufferSize = sizeof ( *info );
 		DBG ( " returning %04x:%04x+%04x['%x']",
 		      get_cached_info->Buffer.segment,

src/interface/pxe/pxe_undi.c

 		undi_isr->FrameHeaderLength =
 			pxe_netdev->ll_protocol->ll_header_len;
 		undi_isr->Frame.segment = rm_ds;
-		undi_isr->Frame.offset =
-			( ( unsigned ) & __from_data16 ( basemem_packet ) );
+		undi_isr->Frame.offset = __from_data16 ( basemem_packet );
 		/* Probably ought to fill in packet type */
 		undi_isr->ProtType = P_UNKNOWN;
 		undi_isr->PktType = XMT_DESTADDR;