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) BS->UnloadImage(*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 = xpool_print(L"\\EFI\\systemd\\drivers\\%s", fname);
  29         path = FileDevicePath(loaded_image->DeviceHandle, spath);
  30         if (!path)
  31                 return log_oom();
  32
  33         err = BS->LoadImage(FALSE, parent_image, path, NULL, 0, &image);
  34         if (EFI_ERROR(err))
  35                 return log_error_status_stall(err, L"Failed to load image %s: %r", fname, err);
  36
  37         err = BS->HandleProtocol(image, &LoadedImageProtocol, (void **)&loaded_image);
  38         if (EFI_ERROR(err))
  39                 return log_error_status_stall(err, L"Failed to find protocol in driver image s: %r", fname, err);
  40
  41         if (loaded_image->ImageCodeType != EfiBootServicesCode &&
  42             loaded_image->ImageCodeType != EfiRuntimeServicesCode)
  43                 return log_error_status_stall(EFI_INVALID_PARAMETER, L"Image %s is not a driver, refusing: %r", fname);
  44
  45         err = BS->StartImage(image, NULL, NULL);
  46         if (EFI_ERROR(err))
  47                 return log_error_status_stall(err, L"Failed to start image %s: %r", fname, err);
  48
  49         TAKE_PTR(image);
  50         return EFI_SUCCESS;
  51 }
  52
  53 static EFI_STATUS reconnect(void) {
  54           _cleanup_freepool_ EFI_HANDLE *handles = NULL;
  55           UINTN n_handles = 0;
  56           EFI_STATUS err;
  57
  58           /* Reconnects all handles, so that any loaded drivers can take effect. */
  59
  60           err = BS->LocateHandleBuffer(AllHandles, NULL, NULL, &n_handles, &handles);
  61           if (EFI_ERROR(err))
  62                   return log_error_status_stall(err, L"Failed to get list of handles: %r", err);
  63
  64           for (UINTN i = 0; i < n_handles; i++) {
  65                   err = BS->ConnectController(handles[i], NULL, NULL, TRUE);
  66                   if (err == EFI_NOT_FOUND) /* No drivers for this handle */
  67                           continue;
  68                   if (EFI_ERROR(err))
  69                           log_error_status_stall(err, L"Failed to reconnect handle %u, ignoring: %r", i, err);
  70           }
  71
  72           return EFI_SUCCESS;
  73 }
  74
  75 EFI_STATUS load_drivers(
  76                 EFI_HANDLE parent_image,
  77                 EFI_LOADED_IMAGE *loaded_image,
  78                 EFI_FILE_HANDLE root_dir) {
  79
  80         _cleanup_(FileHandleClosep) EFI_FILE_HANDLE drivers_dir = NULL;
  81         _cleanup_freepool_ EFI_FILE_INFO *dirent = NULL;
  82         UINTN dirent_size = 0, n_succeeded = 0;
  83         EFI_STATUS err;
  84
  85         err = open_directory(
  86                         root_dir,
  87                         L"\\EFI\\systemd\\drivers",
  88                         &drivers_dir);
  89         if (err == EFI_NOT_FOUND)
  90                 return EFI_SUCCESS;
  91         if (EFI_ERROR(err))
  92                 return log_error_status_stall(err, L"Failed to open \\EFI\\systemd\\drivers: %r", err);
  93
  94         for (;;) {
  95                 err = readdir_harder(drivers_dir, &dirent, &dirent_size);
  96                 if (EFI_ERROR(err))
  97                         return log_error_status_stall(err, L"Failed to read extra directory of loaded image: %r", err);
  98                 if (!dirent) /* End of directory */
  99                         break;
 100
 101                 if (dirent->FileName[0] == '.')
 102                         continue;
 103                 if (FLAGS_SET(dirent->Attribute, EFI_FILE_DIRECTORY))
 104                         continue;
 105                 if (!endswith_no_case(dirent->FileName, EFI_MACHINE_TYPE_NAME L".efi"))
 106                         continue;
 107
 108                 err = load_one_driver(parent_image, loaded_image, dirent->FileName);
 109                 if (EFI_ERROR(err))
 110                         continue;
 111
 112                 n_succeeded++;
 113         }
 114
 115         if (n_succeeded > 0)
 116                 (void) reconnect();
 117
 118         return EFI_SUCCESS;
 119 }