src/boot/efi/drivers.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <efi.h>
   4 #include <efilib.h>
   5
   6 #include "drivers.h"
   7 #include "util.h"
   8
   9 static VOID efi_unload_image(EFI_HANDLE *h) {
  10         if (*h)
  11                 (VOID) uefi_call_wrapper(BS->UnloadImage, 1, *h);
  12 }
  13
  14 static EFI_STATUS load_one_driver(
  15                 EFI_HANDLE parent_image,
  16                 EFI_LOADED_IMAGE *loaded_image,
  17                 const CHAR16 *fname) {
  18
  19         _cleanup_(efi_unload_image) EFI_HANDLE image = NULL;
  20         _cleanup_freepool_ EFI_DEVICE_PATH *path = NULL;
  21         _cleanup_freepool_ CHAR16 *spath = NULL;
  22         EFI_STATUS err;
  23
  24         assert(parent_image);
  25         assert(loaded_image);
  26         assert(fname);
  27
  28         spath = PoolPrint(L"\\EFI\\systemd\\drivers\\%s", fname);
  29         if (!spath)
  30                 return log_oom();
  31
  32         path = FileDevicePath(loaded_image->DeviceHandle, spath);
  33         if (!path)
  34                 return log_oom();
  35
  36         err = uefi_call_wrapper(
  37                         BS->LoadImage, 6,
  38                         FALSE,
  39                         parent_image,
  40                         path,
  41                         NULL, 0,
  42                         &image);
  43         if (EFI_ERROR(err))
  44                 return log_error_status_stall(err, L"Failed to load image %s: %r", fname, err);
  45
  46         err = uefi_call_wrapper(
  47                         BS->HandleProtocol, 3,
  48                         image,
  49                         &LoadedImageProtocol,
  50                         (VOID **)&loaded_image);
  51         if (EFI_ERROR(err))
  52                 return log_error_status_stall(err, L"Failed to find protocol in driver image s: %r", fname, err);
  53
  54         if (loaded_image->ImageCodeType != EfiBootServicesCode &&
  55             loaded_image->ImageCodeType != EfiRuntimeServicesCode)
  56                 return log_error_status_stall(EFI_INVALID_PARAMETER, L"Image %s is not a driver, refusing: %r", fname);
  57
  58         err = uefi_call_wrapper(
  59                         BS->StartImage, 3,
  60                         image,
  61                         NULL,
  62                         NULL);
  63         if (EFI_ERROR(err))
  64                 return log_error_status_stall(err, L"Failed to start image %s: %r", fname, err);
  65
  66         TAKE_PTR(image);
  67         return EFI_SUCCESS;
  68 }
  69
  70 static EFI_STATUS reconnect(VOID) {
  71           _cleanup_freepool_ EFI_HANDLE *handles = NULL;
  72           UINTN n_handles = 0;
  73           EFI_STATUS err;
  74
  75           /* Reconnects all handles, so that any loaded drivers can take effect. */
  76
  77           err = uefi_call_wrapper(
  78                           BS->LocateHandleBuffer, 5,
  79                           AllHandles,
  80                           NULL,
  81                           NULL,
  82                           &n_handles,
  83                           &handles);
  84           if (EFI_ERROR(err))
  85                   return log_error_status_stall(err, L"Failed to get list of handles: %r", err);
  86
  87           for (UINTN i = 0; i < n_handles; i++) {
  88                   err = uefi_call_wrapper(
  89                                   BS->ConnectController, 4,
  90                                   handles[i],
  91                                   NULL,
  92                                   NULL,
  93                                   TRUE);
  94                   if (err == EFI_NOT_FOUND) /* No drivers for this handle */
  95                           continue;
  96                   if (EFI_ERROR(err))
  97                           log_error_status_stall(err, L"Failed to reconnect handle %u, ignoring: %r", i, err);
  98           }
  99
 100           return EFI_SUCCESS;
 101 }
 102
 103 EFI_STATUS load_drivers(
 104                 EFI_HANDLE parent_image,
 105                 EFI_LOADED_IMAGE *loaded_image,
 106                 EFI_FILE_HANDLE root_dir) {
 107
 108         _cleanup_(FileHandleClosep) EFI_FILE_HANDLE drivers_dir = NULL;
 109         _cleanup_freepool_ EFI_FILE_INFO *dirent = NULL;
 110         _cleanup_freepool_ EFI_DEVICE_PATH *path = NULL;
 111         UINTN dirent_size = 0, n_succeeded = 0;
 112         EFI_STATUS err;
 113
 114         err = open_directory(
 115                         root_dir,
 116                         L"\\EFI\\systemd\\drivers",
 117                         &drivers_dir);
 118         if (err == EFI_NOT_FOUND)
 119                 return EFI_SUCCESS;
 120         if (EFI_ERROR(err))
 121                 return log_error_status_stall(err, L"Failed to open \\EFI\\systemd\\drivers: %r", err);
 122
 123         for (;;) {
 124                 _cleanup_freepool_ CHAR16 *d = NULL;
 125
 126                 err = readdir_harder(drivers_dir, &dirent, &dirent_size);
 127                 if (EFI_ERROR(err))
 128                         return log_error_status_stall(err, L"Failed to read extra directory of loaded image: %r", err);
 129                 if (!dirent) /* End of directory */
 130                         break;
 131
 132                 if (dirent->FileName[0] == '.')
 133                         continue;
 134                 if (dirent->Attribute & EFI_FILE_DIRECTORY)
 135                         continue;
 136                 if (!endswith_no_case(dirent->FileName, EFI_MACHINE_TYPE_NAME L".efi"))
 137                         continue;
 138
 139                 err = load_one_driver(parent_image, loaded_image, dirent->FileName);
 140                 if (EFI_ERROR(err))
 141                         continue;
 142
 143                 n_succeeded++;
 144         }
 145
 146         if (n_succeeded > 0)
 147                 (VOID) reconnect();
 148
 149         return EFI_SUCCESS;
 150 }