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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 
     43   InitializeLib(ImageHandle, SystemTable);
     44 
     45   avb_printv("UEFI AVB-based bootloader using libavb version ",
     46              avb_version_string(),
     47              "\n",
     48              NULL);
     49 
     50   ops = uefi_avb_ops_new(ImageHandle);
     51   if (ops == NULL) {
     52     avb_fatal("Error allocating AvbOps.\n");
     53   }
     54 
     55   if (ops->read_is_device_unlocked(ops, &unlocked) != AVB_IO_RESULT_OK) {
     56     avb_fatal("Error determining whether device is unlocked.\n");
     57   }
     58   avb_printv("read_is_device_unlocked() ops returned that device is ",
     59              unlocked ? "UNLOCKED" : "LOCKED",
     60              "\n",
     61              NULL);
     62 
     63   ab_result = avb_ab_flow(ops->ab_ops,
     64                           requested_partitions,
     65                           unlocked /* allow_verification_error */,
     66                           &slot_data);
     67   avb_printv("avb_ab_flow() returned ",
     68              avb_ab_flow_result_to_string(ab_result),
     69              "\n",
     70              NULL);
     71   switch (ab_result) {
     72     case AVB_AB_FLOW_RESULT_OK:
     73     case AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR:
     74       avb_printv("slot_suffix:    ", slot_data->ab_suffix, "\n", NULL);
     75       avb_printv("cmdline:        ", slot_data->cmdline, "\n", NULL);
     76       avb_printv(
     77           "release string: ",
     78           (const char*)((((AvbVBMetaImageHeader*)(slot_data->vbmeta_images[0]
     79                                                       .vbmeta_data)))
     80                             ->release_string),
     81           "\n",
     82           NULL);
     83       /* Pass 'skip_initramfs' since we're not booting into recovery
     84        * mode. Also pass the selected slot in androidboot.slot_suffix.
     85        */
     86       additional_cmdline = avb_strdupv("skip_initramfs ",
     87                                        "androidboot.slot_suffix=",
     88                                        slot_data->ab_suffix,
     89                                        NULL);
     90       if (additional_cmdline == NULL) {
     91         avb_fatal("Error allocating additional_cmdline.\n");
     92       }
     93       boot_result =
     94           uefi_avb_boot_kernel(ImageHandle, slot_data, additional_cmdline);
     95       avb_fatalv("uefi_avb_boot_kernel() failed with error ",
     96                  uefi_avb_boot_kernel_result_to_string(boot_result),
     97                  "\n",
     98                  NULL);
     99       avb_slot_verify_data_free(slot_data);
    100       avb_free(additional_cmdline);
    101       break;
    102     case AVB_AB_FLOW_RESULT_ERROR_OOM:
    103       avb_fatal("OOM error while doing A/B select flow.\n");
    104       break;
    105     case AVB_AB_FLOW_RESULT_ERROR_IO:
    106       avb_fatal("I/O error while doing A/B select flow.\n");
    107       break;
    108     case AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS:
    109       avb_fatal("No bootable slots - enter repair mode\n");
    110       break;
    111   }
    112   uefi_avb_ops_free(ops);
    113 
    114   return EFI_SUCCESS;
    115 }
    116