src/image/efi_image.c

   1 /*
   2  * Copyright (C) 2008 Michael Brown <mbrown@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 <errno.h>
  22 #include <gpxe/efi/efi.h>
  23 #include <gpxe/image.h>
  24 #include <gpxe/init.h>
  25 #include <gpxe/features.h>
  26
  27 FEATURE ( FEATURE_IMAGE, "EFI", DHCP_EB_FEATURE_EFI, 1 );
  28
  29 struct image_type efi_image_type __image_type ( PROBE_NORMAL );
  30
  31 /** Event used to signal shutdown */
  32 static EFI_EVENT efi_shutdown_event;
  33
  34 /**
  35  * Shut down in preparation for booting an OS.
  36  *
  37  * This hook gets called at ExitBootServices time in order to make sure that
  38  * the network cards are properly shut down before the OS takes over.
  39  */
  40 static EFIAPI void efi_shutdown_hook ( EFI_EVENT event __unused,
  41                                        void *context __unused ) {
  42         shutdown ( SHUTDOWN_BOOT );
  43 }
  44
  45 /**
  46  * Execute EFI image
  47  *
  48  * @v image             EFI image
  49  * @ret rc              Return status code
  50  */
  51 static int efi_image_exec ( struct image *image ) {
  52         EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
  53         EFI_HANDLE handle;
  54         UINTN exit_data_size;
  55         CHAR16 *exit_data;
  56         EFI_STATUS efirc;
  57         int rc;
  58
  59         /* Attempt loading image */
  60         if ( ( efirc = bs->LoadImage ( FALSE, efi_image_handle, NULL,
  61                                        user_to_virt ( image->data, 0 ),
  62                                        image->len, &handle ) ) != 0 ) {
  63                 /* Not an EFI image */
  64                 DBGC ( image, "EFIIMAGE %p could not load: %s\n",
  65                        image, efi_strerror ( efirc ) );
  66                 return -ENOEXEC;
  67         }
  68
  69         /* Be sure to shut down the NIC at ExitBootServices time, or else
  70          * DMA from the card can corrupt the OS.
  71          */
  72         efirc = bs->CreateEvent ( EVT_SIGNAL_EXIT_BOOT_SERVICES,
  73                                   TPL_CALLBACK, efi_shutdown_hook,
  74                                   NULL, &efi_shutdown_event );
  75         if ( efirc ) {
  76                 rc = EFIRC_TO_RC ( efirc );
  77                 goto done;
  78         }
  79
  80         /* Start the image */
  81         if ( ( efirc = bs->StartImage ( handle, &exit_data_size,
  82                                         &exit_data ) ) != 0 ) {
  83                 DBGC ( image, "EFIIMAGE %p returned with status %s\n",
  84                        image, efi_strerror ( efirc ) );
  85         }
  86
  87         rc = EFIRC_TO_RC ( efirc );
  88
  89         /* Remove the shutdown hook */
  90         bs->CloseEvent ( efi_shutdown_event );
  91
  92 done:
  93         /* Unload the image.  We can't leave it loaded, because we
  94          * have no "unload" operation.
  95          */
  96         bs->UnloadImage ( handle );
  97
  98         return rc;
  99 }
 100
 101 /**
 102  * Load EFI image into memory
 103  *
 104  * @v image             EFI file
 105  * @ret rc              Return status code
 106  */
 107 static int efi_image_load ( struct image *image ) {
 108         EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 109         EFI_HANDLE handle;
 110         EFI_STATUS efirc;
 111
 112         /* Attempt loading image */
 113         if ( ( efirc = bs->LoadImage ( FALSE, efi_image_handle, NULL,
 114                                        user_to_virt ( image->data, 0 ),
 115                                        image->len, &handle ) ) != 0 ) {
 116                 /* Not an EFI image */
 117                 DBGC ( image, "EFIIMAGE %p could not load: %s\n",
 118                        image, efi_strerror ( efirc ) );
 119                 return -ENOEXEC;
 120         }
 121
 122         /* This is an EFI image */
 123         if ( ! image->type )
 124                 image->type = &efi_image_type;
 125
 126         /* Unload the image.  We can't leave it loaded, because we
 127          * have no "unload" operation.
 128          */
 129         bs->UnloadImage ( handle );
 130
 131         return 0;
 132 }
 133
 134 /** EFI image type */
 135 struct image_type efi_image_type __image_type ( PROBE_NORMAL ) = {
 136         .name = "EFI",
 137         .load = efi_image_load,
 138         .exec = efi_image_exec,
 139 };