Fix up building with gcc 4.0.1 / gas 2.16.91

src/arch/i386/Config

 endif
 GCC_MINORVERSION = $(word 2, $(GCC_VERSION))
 ifneq ($(GCC_MINORVERSION),4)
-CFLAGS+=	-mcpu=i386
+CFLAGS+=	-march=i386
 endif
 
 LDFLAGS+=	-N

src/arch/i386/prefix/romprefix.S

 	.byte	0			/* Structure revision */
 	.byte	0,1,2			/* PXE version 2.1.0 */
 	.word	UNDILoader - _prefix	/* Offset to loader routine */
-	.word	UNDIStackSize		/* Stack segment size */
-	.word	UNDIDataSize		/* Data segment size */
-	.word	UNDICodeSize		/* Code segment size */
+	.word	_real_mode_stack_size	/* Stack segment size */
+	.word	_real_mode_stack_size	/* Data segment size */
+	.word	_pxe_stack_size		/* Code segment size */
 	.ascii	"PCIR"
 
 	/* The code segment contains our pxe_stack_t plus the PXE and

src/include/etherboot.h

 extern jmp_buf restart_etherboot;
 extern int url_port;
 extern struct arptable_t arptable[MAX_ARP];
-extern struct igmptable_t igmptable[MAX_IGMP];
 #ifdef	IMAGE_MENU
 extern int menutmo,menudefault;
 extern unsigned char *defparams;