Home | History | Annotate | Download | only in efi
      1 /*
      2  * Copyright (C) 2008 Michael Brown <mbrown (at) fensystems.co.uk>.
      3  *
      4  * This program is free software; you can redistribute it and/or
      5  * modify it under the terms of the GNU General Public License as
      6  * published by the Free Software Foundation; either version 2 of the
      7  * License, or any later version.
      8  *
      9  * This program is distributed in the hope that it will be useful, but
     10  * WITHOUT ANY WARRANTY; without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     12  * General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU General Public License
     15  * along with this program; if not, write to the Free Software
     16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
     17  */
     18 
     19 FILE_LICENCE ( GPL2_OR_LATER );
     20 
     21 #include <string.h>
     22 #include <gpxe/efi/efi.h>
     23 #include <gpxe/uuid.h>
     24 
     25 /** Image handle passed to entry point */
     26 EFI_HANDLE efi_image_handle;
     27 
     28 /** System table passed to entry point */
     29 EFI_SYSTEM_TABLE *efi_systab;
     30 
     31 /**
     32  * Look up EFI configuration table
     33  *
     34  * @v guid		Configuration table GUID
     35  * @ret table		Configuration table, or NULL
     36  */
     37 static void * efi_find_table ( EFI_GUID *guid ) {
     38 	unsigned int i;
     39 
     40 	for ( i = 0 ; i < efi_systab->NumberOfTableEntries ; i++ ) {
     41 		if ( memcmp ( &efi_systab->ConfigurationTable[i].VendorGuid,
     42 			      guid, sizeof ( *guid ) ) == 0 )
     43 			return efi_systab->ConfigurationTable[i].VendorTable;
     44 	}
     45 
     46 	return NULL;
     47 }
     48 
     49 /**
     50  * Initialise EFI environment
     51  *
     52  * @v image_handle	Image handle
     53  * @v systab		System table
     54  * @ret efirc		EFI return status code
     55  */
     56 EFI_STATUS efi_init ( EFI_HANDLE image_handle,
     57 		      EFI_SYSTEM_TABLE *systab ) {
     58 	EFI_BOOT_SERVICES *bs;
     59 	struct efi_protocol *prot;
     60 	struct efi_config_table *tab;
     61 	EFI_STATUS efirc;
     62 
     63 	/* Store image handle and system table pointer for future use */
     64 	efi_image_handle = image_handle;
     65 	efi_systab = systab;
     66 
     67 	/* Sanity checks */
     68 	if ( ! systab )
     69 		return EFI_NOT_AVAILABLE_YET;
     70 	if ( ! systab->ConOut )
     71 		return EFI_NOT_AVAILABLE_YET;
     72 	if ( ! systab->BootServices ) {
     73 		DBGC ( systab, "EFI provided no BootServices entry point\n" );
     74 		return EFI_NOT_AVAILABLE_YET;
     75 	}
     76 	if ( ! systab->RuntimeServices ) {
     77 		DBGC ( systab, "EFI provided no RuntimeServices entry "
     78 		       "point\n" );
     79 		return EFI_NOT_AVAILABLE_YET;
     80 	}
     81 	DBGC ( systab, "EFI handle %p systab %p\n", image_handle, systab );
     82 
     83 	/* Look up used protocols */
     84 	bs = systab->BootServices;
     85 	for_each_table_entry ( prot, EFI_PROTOCOLS ) {
     86 		if ( ( efirc = bs->LocateProtocol ( &prot->u.guid, NULL,
     87 						    prot->protocol ) ) == 0 ) {
     88 			DBGC ( systab, "EFI protocol %s is at %p\n",
     89 			       uuid_ntoa ( &prot->u.uuid ), *(prot->protocol));
     90 		} else {
     91 			DBGC ( systab, "EFI does not provide protocol %s\n",
     92 			       uuid_ntoa ( &prot->u.uuid ) );
     93 			/* All protocols are required */
     94 			return efirc;
     95 		}
     96 	}
     97 
     98 	/* Look up used configuration tables */
     99 	for_each_table_entry ( tab, EFI_CONFIG_TABLES ) {
    100 		if ( ( *(tab->table) = efi_find_table ( &tab->u.guid ) ) ) {
    101 			DBGC ( systab, "EFI configuration table %s is at %p\n",
    102 			       uuid_ntoa ( &tab->u.uuid ), *(tab->table) );
    103 		} else {
    104 			DBGC ( systab, "EFI does not provide configuration "
    105 			       "table %s\n", uuid_ntoa ( &tab->u.uuid ) );
    106 			if ( tab->required )
    107 				return EFI_NOT_AVAILABLE_YET;
    108 		}
    109 	}
    110 
    111 	return 0;
    112 }
    113