efi_watchdog.c File Reference

EFI watchdog holdoff timer. More...

#include <errno.h>
#include <string.h>
#include <ipxe/retry.h>
#include <ipxe/timer.h>
#include <ipxe/init.h>
#include <ipxe/efi/efi.h>
#include <ipxe/efi/efi_watchdog.h>

Go to the source code of this file.

Macros
#define	WATCHDOG_HOLDOFF_SECS   10
	Watchdog holdoff interval (in seconds)
#define	WATCHDOG_TIMEOUT_SECS   ( 5 * 60 )
	Watchdog timeout (in seconds)
#define	WATCHDOG_CODE   0x6950584544454144ULL
	Watchdog code (to be logged on watchdog timeout)
#define	WATCHDOG_DATA   L"iPXE";
	Watchdog data (to be logged on watchdog timeout)

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static void	efi_watchdog_expired (struct retry_timer *timer, int over __unused)
	Hold off watchdog timer.
static void	efi_watchdog_shutdown (int booting)
	Disable watching when shutting down to boot an operating system.
struct startup_fn efi_watchdog_startup_fn	__startup_fn (STARTUP_EARLY)
	Watchdog startup/shutdown function.

Variables
struct retry_timer	efi_watchdog = TIMER_INIT ( efi_watchdog_expired )
	Watchdog holdoff timer.

Detailed Description

EFI watchdog holdoff timer.

Definition in file efi_watchdog.c.

Macro Definition Documentation

WATCHDOG_HOLDOFF_SECS

#define WATCHDOG_HOLDOFF_SECS   10

Watchdog holdoff interval (in seconds)

Definition at line 43 of file efi_watchdog.c.

Referenced by efi_watchdog_expired().

WATCHDOG_TIMEOUT_SECS

#define WATCHDOG_TIMEOUT_SECS   ( 5 * 60 )

Watchdog timeout (in seconds)

Definition at line 46 of file efi_watchdog.c.

Referenced by efi_watchdog_expired().

WATCHDOG_CODE

#define WATCHDOG_CODE   0x6950584544454144ULL

Watchdog code (to be logged on watchdog timeout)

Definition at line 49 of file efi_watchdog.c.

Referenced by efi_watchdog_expired().

WATCHDOG_DATA

#define WATCHDOG_DATA   L"iPXE";

Watchdog data (to be logged on watchdog timeout)

Definition at line 52 of file efi_watchdog.c.

Referenced by efi_watchdog_expired().

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

efi_watchdog_expired()

void efi_watchdog_expired ( struct retry_timer * timer, int over __unused )

static

Hold off watchdog timer.

Parameters

retry	Retry timer
over	Failure indicator

Definition at line 60 of file efi_watchdog.c.

                                                       {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        static CHAR16 data[] = WATCHDOG_DATA;
        EFI_STATUS efirc;
        int rc;
 
        DBGC2 ( timer, "EFI holding off watchdog timer\n" );
 
        /* Restart this holdoff timer */
        start_timer_fixed ( timer, ( WATCHDOG_HOLDOFF_SECS * TICKS_PER_SEC ) );
 
        /* Reset watchdog timer */
        if ( ( efirc = bs->SetWatchdogTimer ( WATCHDOG_TIMEOUT_SECS,
                                              WATCHDOG_CODE, sizeof ( data ),
                                              data ) ) != 0 ) {
                rc = -EEFI ( efirc );
                DBGC ( timer, "EFI could not set watchdog timer: %s\n",
                       strerror ( rc ) );
                return;
        }
}

References __unused, data, DBGC, DBGC2, EEFI, efi_systab, rc, EFI_BOOT_SERVICES::SetWatchdogTimer, start_timer_fixed(), strerror(), TICKS_PER_SEC, WATCHDOG_CODE, WATCHDOG_DATA, WATCHDOG_HOLDOFF_SECS, and WATCHDOG_TIMEOUT_SECS.

efi_watchdog_shutdown()

void efi_watchdog_shutdown ( int booting )

static

Disable watching when shutting down to boot an operating system.

Parameters

booting

System is shutting down for OS boot

Definition at line 91 of file efi_watchdog.c.

                                                  {
        EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
        EFI_STATUS efirc;
        int rc;
 
        /* If we are shutting down to boot an operating system, then
         * disable the boot services watchdog timer.  The UEFI
         * specification mandates that the platform firmware does this
         * as part of the ExitBootServices() call, but some platforms
         * (e.g. Hyper-V) are observed to occasionally forget to do
         * so, resulting in a reboot approximately five minutes after
         * starting the operating system.
         */
        if ( booting &&
             ( ( efirc = bs->SetWatchdogTimer ( 0, 0, 0, NULL ) ) != 0 ) ) {
                rc = -EEFI ( efirc );
                DBGC ( &efi_watchdog, "EFI could not disable watchdog timer: "
                       "%s\n", strerror ( rc ) );
                /* Nothing we can do */
        }
}

References DBGC, EEFI, efi_systab, efi_watchdog, NULL, rc, EFI_BOOT_SERVICES::SetWatchdogTimer, and strerror().

Referenced by __startup_fn().

__startup_fn()

struct startup_fn efi_watchdog_startup_fn __startup_fn

(

STARTUP_EARLY

)

Watchdog startup/shutdown function.

References __startup_fn, efi_watchdog_shutdown(), and STARTUP_EARLY.

Variable Documentation

efi_watchdog

struct retry_timer efi_watchdog = TIMER_INIT ( efi_watchdog_expired )

Watchdog holdoff timer.

Definition at line 84 of file efi_watchdog.c.

Referenced by efi_watchdog_shutdown(), efi_watchdog_start(), efi_watchdog_stop(), and FILE_SECBOOT().