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 = 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 = BS->LoadImage(FALSE, parent_image, path, NULL, 0, &image);
  37         if (EFI_ERROR(err))
  38                 return log_error_status_stall(err, L"Failed to load image %s: %r", fname, err);
  39
  40         err = BS->HandleProtocol(image, &LoadedImageProtocol, (void **)&loaded_image);
  41         if (EFI_ERROR(err))
  42                 return log_error_status_stall(err, L"Failed to find protocol in driver image s: %r", fname, err);
  43
  44         if (loaded_image->ImageCodeType != EfiBootServicesCode &&
  45             loaded_image->ImageCodeType != EfiRuntimeServicesCode)
  46                 return log_error_status_stall(EFI_INVALID_PARAMETER, L"Image %s is not a driver, refusing: %r", fname);
  47
  48         err = BS->StartImage(image, NULL, NULL);
  49         if (EFI_ERROR(err))
  50                 return log_error_status_stall(err, L"Failed to start image %s: %r", fname, err);
  51
  52         TAKE_PTR(image);
  53         return EFI_SUCCESS;
  54 }
  55
  56 static EFI_STATUS reconnect(void) {
  57           _cleanup_freepool_ EFI_HANDLE *handles = NULL;
  58           UINTN n_handles = 0;
  59           EFI_STATUS err;
  60
  61           /* Reconnects all handles, so that any loaded drivers can take effect. */
  62
  63           err = BS->LocateHandleBuffer(AllHandles, NULL, NULL, &n_handles, &handles);
  64           if (EFI_ERROR(err))
  65                   return log_error_status_stall(err, L"Failed to get list of handles: %r", err);
  66
  67           for (UINTN i = 0; i < n_handles; i++) {
  68                   err = BS->ConnectController(handles[i], NULL, NULL, TRUE);
  69                   if (err == EFI_NOT_FOUND) /* No drivers for this handle */
  70                           continue;
  71                   if (EFI_ERROR(err))
  72                           log_error_status_stall(err, L"Failed to reconnect handle %u, ignoring: %r", i, err);
  73           }
  74
  75           return EFI_SUCCESS;
  76 }
  77
  78 EFI_STATUS load_drivers(
  79                 EFI_HANDLE parent_image,
  80                 EFI_LOADED_IMAGE *loaded_image,
  81                 EFI_FILE_HANDLE root_dir) {
  82
  83         _cleanup_(FileHandleClosep) EFI_FILE_HANDLE drivers_dir = NULL;
  84         _cleanup_freepool_ EFI_FILE_INFO *dirent = NULL;
  85         UINTN dirent_size = 0, n_succeeded = 0;
  86         EFI_STATUS err;
  87
  88         err = open_directory(
  89                         root_dir,
  90                         L"\\EFI\\systemd\\drivers",
  91                         &drivers_dir);
  92         if (err == EFI_NOT_FOUND)
  93                 return EFI_SUCCESS;
  94         if (EFI_ERROR(err))
  95                 return log_error_status_stall(err, L"Failed to open \\EFI\\systemd\\drivers: %r", err);
  96
  97         for (;;) {
  98                 err = readdir_harder(drivers_dir, &dirent, &dirent_size);
  99                 if (EFI_ERROR(err))
 100                         return log_error_status_stall(err, L"Failed to read extra directory of loaded image: %r", err);
 101                 if (!dirent) /* End of directory */
 102                         break;
 103
 104                 if (dirent->FileName[0] == '.')
 105                         continue;
 106                 if (dirent->Attribute & EFI_FILE_DIRECTORY)
 107                         continue;
 108                 if (!endswith_no_case(dirent->FileName, EFI_MACHINE_TYPE_NAME L".efi"))
 109                         continue;
 110
 111                 err = load_one_driver(parent_image, loaded_image, dirent->FileName);
 112                 if (EFI_ERROR(err))
 113                         continue;
 114
 115                 n_succeeded++;
 116         }
 117
 118         if (n_succeeded > 0)
 119                 (void) reconnect();
 120
 121         return EFI_SUCCESS;
 122 }