efi_loader: implement SetWatchdogTimer
The watchdog is initialized with a 5 minute timeout period.
It can be reset by SetWatchdogTimer.
It is stopped by ExitBoottimeServices.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_watchdog.c b/lib/efi_loader/efi_watchdog.c
new file mode 100644
index 0000000..35a45de
--- /dev/null
+++ b/lib/efi_loader/efi_watchdog.c
@@ -0,0 +1,89 @@
+/*
+ * EFI watchdog
+ *
+ * Copyright (c) 2017 Heinrich Schuchardt
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <efi_loader.h>
+
+/* Conversion factor from seconds to multiples of 100ns */
+#define EFI_SECONDS_TO_100NS 10000000ULL
+
+static struct efi_event *watchdog_timer_event;
+
+/*
+ * Reset the system when the watchdog event is notified.
+ *
+ * @event: the watchdog event
+ * @context: not used
+ */
+static void EFIAPI efi_watchdog_timer_notify(struct efi_event *event,
+ void *context)
+{
+ EFI_ENTRY("%p, %p", event, context);
+
+ printf("\nEFI: Watchdog timeout\n");
+ EFI_CALL_VOID(efi_runtime_services.reset_system(EFI_RESET_COLD,
+ EFI_SUCCESS, 0, NULL));
+
+ EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+/*
+ * Reset the watchdog timer.
+ *
+ * This function is used by the SetWatchdogTimer service.
+ *
+ * @timeout: seconds before reset by watchdog
+ * @return: status code
+ */
+efi_status_t efi_set_watchdog(unsigned long timeout)
+{
+ efi_status_t r;
+
+ if (timeout)
+ /* Reset watchdog */
+ r = efi_set_timer(watchdog_timer_event, EFI_TIMER_RELATIVE,
+ EFI_SECONDS_TO_100NS * timeout);
+ else
+ /* Deactivate watchdog */
+ r = efi_set_timer(watchdog_timer_event, EFI_TIMER_STOP, 0);
+ return r;
+}
+
+/*
+ * Initialize the EFI watchdog.
+ *
+ * This function is called by efi_init_obj_list()
+ */
+int efi_watchdog_register(void)
+{
+ efi_status_t r;
+
+ /*
+ * Create a timer event.
+ */
+ r = efi_create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
+ efi_watchdog_timer_notify, NULL,
+ &watchdog_timer_event);
+ if (r != EFI_SUCCESS) {
+ printf("ERROR: Failed to register watchdog event\n");
+ return r;
+ }
+ /*
+ * The UEFI standard requires that the watchdog timer is set to five
+ * minutes when invoking an EFI boot option.
+ *
+ * Unified Extensible Firmware Interface (UEFI), version 2.7 Errata A
+ * 7.5. Miscellaneous Boot Services - EFI_BOOT_SERVICES.SetWatchdogTimer
+ */
+ r = efi_set_watchdog(300);
+ if (r != EFI_SUCCESS) {
+ printf("ERROR: Failed to set watchdog timer\n");
+ return r;
+ }
+ return 0;
+}