1 // SPDX-License-Identifier: GPL-2.0+
5 * Copyright (c) 2017 Heinrich Schuchardt
9 #include <efi_loader.h>
11 /* Conversion factor from seconds to multiples of 100ns */
12 #define EFI_SECONDS_TO_100NS 10000000ULL
14 static struct efi_event *watchdog_timer_event;
17 * Reset the system when the watchdog event is notified.
19 * @event: the watchdog event
22 static void EFIAPI efi_watchdog_timer_notify(struct efi_event *event,
25 EFI_ENTRY("%p, %p", event, context);
27 printf("\nEFI: Watchdog timeout\n");
28 EFI_CALL_VOID(efi_runtime_services.reset_system(EFI_RESET_COLD,
29 EFI_SUCCESS, 0, NULL));
31 EFI_EXIT(EFI_UNSUPPORTED);
35 * Reset the watchdog timer.
37 * This function is used by the SetWatchdogTimer service.
39 * @timeout: seconds before reset by watchdog
40 * @return: status code
42 efi_status_t efi_set_watchdog(unsigned long timeout)
48 r = efi_set_timer(watchdog_timer_event, EFI_TIMER_RELATIVE,
49 EFI_SECONDS_TO_100NS * timeout);
51 /* Deactivate watchdog */
52 r = efi_set_timer(watchdog_timer_event, EFI_TIMER_STOP, 0);
57 * Initialize the EFI watchdog.
59 * This function is called by efi_init_obj_list()
61 efi_status_t efi_watchdog_register(void)
66 * Create a timer event.
68 r = efi_create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
69 efi_watchdog_timer_notify, NULL, NULL,
70 &watchdog_timer_event);
71 if (r != EFI_SUCCESS) {
72 printf("ERROR: Failed to register watchdog event\n");
76 * The UEFI standard requires that the watchdog timer is set to five
77 * minutes when invoking an EFI boot option.
79 * Unified Extensible Firmware Interface (UEFI), version 2.7 Errata A
80 * 7.5. Miscellaneous Boot Services - EFI_BOOT_SERVICES.SetWatchdogTimer
82 r = efi_set_watchdog(300);
83 if (r != EFI_SUCCESS) {
84 printf("ERROR: Failed to set watchdog timer\n");