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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Permission is hereby granted, free of charge, to any person
      5  * obtaining a copy of this software and associated documentation
      6  * files (the "Software"), to deal in the Software without
      7  * restriction, including without limitation the rights to use, copy,
      8  * modify, merge, publish, distribute, sublicense, and/or sell copies
      9  * of the Software, and to permit persons to whom the Software is
     10  * furnished to do so, subject to the following conditions:
     11  *
     12  * The above copyright notice and this permission notice shall be
     13  * included in all copies or substantial portions of the Software.
     14  *
     15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
     19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
     20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     22  * SOFTWARE.
     23  */
     24 
     25 #include <efi.h>
     26 #include <efilib.h>
     27 
     28 #include <libavb_ab/libavb_ab.h>
     29 
     30 #include "uefi_avb_boot.h"
     31 #include "uefi_avb_ops.h"
     32 
     33 EFI_STATUS EFIAPI efi_main(EFI_HANDLE ImageHandle,
     34                            EFI_SYSTEM_TABLE* SystemTable) {
     35   AvbOps* ops;
     36   AvbABFlowResult ab_result;
     37   AvbSlotVerifyData* slot_data;
     38   UEFIAvbBootKernelResult boot_result;
     39   const char* requested_partitions[] = {"boot", NULL};
     40   bool unlocked = true;
     41   char* additional_cmdline = NULL;
     42   AvbSlotVerifyFlags flags;
     43 
     44   InitializeLib(ImageHandle, SystemTable);
     45 
     46   avb_printv("UEFI AVB-based bootloader using libavb version ",
     47              avb_version_string(),
     48              "\n",
     49              NULL);
     50 
     51   ops = uefi_avb_ops_new(ImageHandle);
     52   if (ops == NULL) {
     53     avb_fatal("Error allocating AvbOps.\n");
     54   }
     55 
     56   if (ops->read_is_device_unlocked(ops, &unlocked) != AVB_IO_RESULT_OK) {
     57     avb_fatal("Error determining whether device is unlocked.\n");
     58   }
     59   avb_printv("read_is_device_unlocked() ops returned that device is ",
     60              unlocked ? "UNLOCKED" : "LOCKED",
     61              "\n",
     62              NULL);
     63 
     64   flags = AVB_SLOT_VERIFY_FLAGS_NONE;
     65   if (unlocked) {
     66     flags |= AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR;
     67   }
     68 
     69   ab_result = avb_ab_flow(ops->ab_ops,
     70                           requested_partitions,
     71                           flags,
     72                           AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
     73                           &slot_data);
     74   avb_printv("avb_ab_flow() returned ",
     75              avb_ab_flow_result_to_string(ab_result),
     76              "\n",
     77              NULL);
     78   switch (ab_result) {
     79     case AVB_AB_FLOW_RESULT_OK:
     80     case AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR:
     81       avb_printv("slot_suffix:    ", slot_data->ab_suffix, "\n", NULL);
     82       avb_printv("cmdline:        ", slot_data->cmdline, "\n", NULL);
     83       avb_printv(
     84           "release string: ",
     85           (const char*)((((AvbVBMetaImageHeader*)(slot_data->vbmeta_images[0]
     86                                                       .vbmeta_data)))
     87                             ->release_string),
     88           "\n",
     89           NULL);
     90       /* Pass 'skip_initramfs' since we're not booting into recovery
     91        * mode. Also pass the selected slot in androidboot.slot and the
     92        * suffix in androidboot.slot_suffix.
     93        */
     94       additional_cmdline = avb_strdupv("skip_initramfs ",
     95                                        "androidboot.slot=",
     96                                        slot_data->ab_suffix + 1,
     97                                        " ",
     98                                        "androidboot.slot_suffix=",
     99                                        slot_data->ab_suffix,
    100                                        NULL);
    101       if (additional_cmdline == NULL) {
    102         avb_fatal("Error allocating additional_cmdline.\n");
    103       }
    104       boot_result =
    105           uefi_avb_boot_kernel(ImageHandle, slot_data, additional_cmdline);
    106       avb_fatalv("uefi_avb_boot_kernel() failed with error ",
    107                  uefi_avb_boot_kernel_result_to_string(boot_result),
    108                  "\n",
    109                  NULL);
    110       avb_slot_verify_data_free(slot_data);
    111       avb_free(additional_cmdline);
    112       break;
    113     case AVB_AB_FLOW_RESULT_ERROR_OOM:
    114       avb_fatal("OOM error while doing A/B select flow.\n");
    115       break;
    116     case AVB_AB_FLOW_RESULT_ERROR_IO:
    117       avb_fatal("I/O error while doing A/B select flow.\n");
    118       break;
    119     case AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS:
    120       avb_fatal("No bootable slots - enter repair mode\n");
    121       break;
    122     case AVB_AB_FLOW_RESULT_ERROR_INVALID_ARGUMENT:
    123       avb_fatal("Invalid arguments passed\n");
    124       break;
    125   }
    126   uefi_avb_ops_free(ops);
    127 
    128   return EFI_SUCCESS;
    129 }
    130