cmd/bootefi.c

   1 /*
   2  *  EFI application loader
   3  *
   4  *  Copyright (c) 2016 Alexander Graf
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <command.h>
  11 #include <efi_loader.h>
  12 #include <errno.h>
  13 #include <libfdt.h>
  14 #include <libfdt_env.h>
  15
  16 /*
  17  * When booting using the "bootefi" command, we don't know which
  18  * physical device the file came from. So we create a pseudo-device
  19  * called "bootefi" with the device path /bootefi.
  20  *
  21  * In addition to the originating device we also declare the file path
  22  * of "bootefi" based loads to be /bootefi.
  23  */
  24 static struct efi_device_path_file_path bootefi_dummy_path[] = {
  25         {
  26                 .dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE,
  27                 .dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH,
  28                 .dp.length = sizeof(bootefi_dummy_path[0]),
  29                 .str = { 'b','o','o','t','e','f','i' },
  30         }, {
  31                 .dp.type = DEVICE_PATH_TYPE_END,
  32                 .dp.sub_type = DEVICE_PATH_SUB_TYPE_END,
  33                 .dp.length = sizeof(bootefi_dummy_path[0]),
  34         }
  35 };
  36
  37 static efi_status_t bootefi_open_dp(void *handle, efi_guid_t *protocol,
  38                         void **protocol_interface, void *agent_handle,
  39                         void *controller_handle, uint32_t attributes)
  40 {
  41         *protocol_interface = bootefi_dummy_path;
  42         return EFI_SUCCESS;
  43 }
  44
  45 /* The EFI loaded_image interface for the image executed via "bootefi" */
  46 static struct efi_loaded_image loaded_image_info = {
  47         .device_handle = bootefi_dummy_path,
  48         .file_path = bootefi_dummy_path,
  49 };
  50
  51 /* The EFI object struct for the image executed via "bootefi" */
  52 static struct efi_object loaded_image_info_obj = {
  53         .handle = &loaded_image_info,
  54         .protocols = {
  55                 {
  56                         /*
  57                          * When asking for the loaded_image interface, just
  58                          * return handle which points to loaded_image_info
  59                          */
  60                         .guid = &efi_guid_loaded_image,
  61                         .open = &efi_return_handle,
  62                 },
  63                 {
  64                         /*
  65                          * When asking for the device path interface, return
  66                          * bootefi_dummy_path
  67                          */
  68                         .guid = &efi_guid_device_path,
  69                         .open = &bootefi_open_dp,
  70                 },
  71         },
  72 };
  73
  74 /* The EFI object struct for the device the "bootefi" image was loaded from */
  75 static struct efi_object bootefi_device_obj = {
  76         .handle = bootefi_dummy_path,
  77         .protocols = {
  78                 {
  79                         /* When asking for the device path interface, return
  80                          * bootefi_dummy_path */
  81                         .guid = &efi_guid_device_path,
  82                         .open = &bootefi_open_dp,
  83                 }
  84         },
  85 };
  86
  87 /*
  88  * Load an EFI payload into a newly allocated piece of memory, register all
  89  * EFI objects it would want to access and jump to it.
  90  */
  91 static unsigned long do_bootefi_exec(void *efi)
  92 {
  93         ulong (*entry)(void *image_handle, struct efi_system_table *st);
  94         ulong fdt_pages, fdt_size, fdt_start, fdt_end;
  95         bootm_headers_t img = { 0 };
  96
  97         /*
  98          * gd lives in a fixed register which may get clobbered while we execute
  99          * the payload. So save it here and restore it on every callback entry
 100          */
 101         efi_save_gd();
 102
 103         /* Update system table to point to our currently loaded FDT */
 104
 105         if (working_fdt) {
 106                 /* Prepare fdt for payload */
 107                 if (image_setup_libfdt(&img, working_fdt, 0, NULL)) {
 108                         printf("ERROR: Failed to process device tree\n");
 109                         return -EINVAL;
 110                 }
 111
 112                 /* Link to it in the efi tables */
 113                 systab.tables[0].guid = EFI_FDT_GUID;
 114                 systab.tables[0].table = working_fdt;
 115                 systab.nr_tables = 1;
 116
 117                 /* And reserve the space in the memory map */
 118                 fdt_start = ((ulong)working_fdt) & ~EFI_PAGE_MASK;
 119                 fdt_end = ((ulong)working_fdt) + fdt_totalsize(working_fdt);
 120                 fdt_size = (fdt_end - fdt_start) + EFI_PAGE_MASK;
 121                 fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
 122                 /* Give a bootloader the chance to modify the device tree */
 123                 fdt_pages += 2;
 124                 efi_add_memory_map(fdt_start, fdt_pages,
 125                                    EFI_BOOT_SERVICES_DATA, true);
 126
 127         } else {
 128                 printf("WARNING: No device tree loaded, expect boot to fail\n");
 129                 systab.nr_tables = 0;
 130         }
 131
 132         /* Load the EFI payload */
 133         entry = efi_load_pe(efi, &loaded_image_info);
 134         if (!entry)
 135                 return -ENOENT;
 136
 137         /* Initialize and populate EFI object list */
 138         INIT_LIST_HEAD(&efi_obj_list);
 139         list_add_tail(&loaded_image_info_obj.link, &efi_obj_list);
 140         list_add_tail(&bootefi_device_obj.link, &efi_obj_list);
 141 #ifdef CONFIG_PARTITIONS
 142         efi_disk_register();
 143 #endif
 144
 145         /* Call our payload! */
 146 #ifdef DEBUG_EFI
 147         printf("%s:%d Jumping to 0x%lx\n", __func__, __LINE__, (long)entry);
 148 #endif
 149         return entry(&loaded_image_info, &systab);
 150 }
 151
 152
 153 /* Interpreter command to boot an arbitrary EFI image from memory */
 154 static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 155 {
 156         char *saddr;
 157         unsigned long addr;
 158         int r = 0;
 159
 160         if (argc < 2)
 161                 return 1;
 162         saddr = argv[1];
 163
 164         addr = simple_strtoul(saddr, NULL, 16);
 165
 166         printf("## Starting EFI application at 0x%08lx ...\n", addr);
 167         r = do_bootefi_exec((void *)addr);
 168         printf("## Application terminated, r = %d\n", r);
 169
 170         if (r != 0)
 171                 r = 1;
 172
 173         return r;
 174 }
 175
 176 #ifdef CONFIG_SYS_LONGHELP
 177 static char bootefi_help_text[] =
 178         "<image address>\n"
 179         "  - boot EFI payload stored at address <image address>\n"
 180         "\n"
 181         "Since most EFI payloads want to have a device tree provided, please\n"
 182         "make sure you load a device tree using the fdt addr command before\n"
 183         "executing bootefi.\n";
 184 #endif
 185
 186 U_BOOT_CMD(
 187         bootefi, 2, 0, do_bootefi,
 188         "Boots an EFI payload from memory\n",
 189         bootefi_help_text
 190 );