[smbios] Provide SMBIOS version number via smbios_version()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/i386/interface/pcbios/bios_smbios.c

 		smbios->address = phys_to_user ( u.entry.smbios_address );
 		smbios->len = u.entry.smbios_len;
 		smbios->count = u.entry.smbios_count;
+		smbios->version =
+			SMBIOS_VERSION ( u.entry.major, u.entry.minor );
 		return 0;
 	}
 

src/include/ipxe/smbios.h

 	size_t len;
 	/** Number of SMBIOS structures */
 	unsigned int count;
+	/** SMBIOS version */
+	uint16_t version;
 };
 
+/**
+ * Calculate SMBIOS version
+ *
+ * @v major		Major version
+ * @v minor		Minor version
+ * @ret version		SMBIOS version
+ */
+#define SMBIOS_VERSION( major, minor ) ( ( (major) << 8 ) | (minor) )
+
 extern int find_smbios ( struct smbios *smbios );
 extern int find_smbios_structure ( unsigned int type,
 				   struct smbios_structure *structure );
 extern int read_smbios_string ( struct smbios_structure *structure,
 				unsigned int index,
 				void *data, size_t len );
+extern int smbios_version ( void );
 
 #endif /* _IPXE_SMBIOS_H */

src/interface/efi/efi_smbios.c

 	smbios->address = phys_to_user ( smbios_entry->smbios_address );
 	smbios->len = smbios_entry->smbios_len;
 	smbios->count = smbios_entry->smbios_count;
+	smbios->version =
+		SMBIOS_VERSION ( smbios_entry->major, smbios_entry->minor );
 	DBG ( "Found SMBIOS v%d.%d entry point at %p (%x+%zx)\n",
 	      smbios_entry->major, smbios_entry->minor, smbios_entry,
 	      smbios_entry->smbios_address, smbios->len );

src/interface/smbios/smbios.c

 	DBG ( "SMBIOS string index %d not found\n", index );
 	return -ENOENT;
 }
+
+/**
+ * Get SMBIOS version
+ *
+ * @ret version		Version, or negative error
+ */
+int smbios_version ( void ) {
+	int rc;
+
+	/* Find SMBIOS */
+	if ( ( smbios.address == UNULL ) &&
+	     ( ( rc = find_smbios ( &smbios ) ) != 0 ) )
+		return rc;
+	assert ( smbios.address != UNULL );
+
+	return smbios.version;
+}