Provided by: freebsd-manpages_12.2-1_all bug


     efidev, efirtc — user-mode access to UEFI runtime services


     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

            options EFIRT

     Alternatively, to load the driver as a module at boot time, place the following line in


     The driver may be disabled by setting the loader(8) tunable efi.rt.disabled to “1”.


     The efidev device provides user-mode access to UEFI runtime services.  efidev also includes
     a driver to provide a time-of-day clock using the UEFI real time clock (RTC).  However, the
     RTC may not always be available, based on the UEFI firmware.  If the RTC is not available,
     it will not be registered as a time-of-day clock and the time related ioctls below will not
     be functional.

     efidev provides the following ioctls defined in <sys/efiio.h> with supplemental structures
     and constants defined in <sys/efi.h>:

     EFIIOC_GET_TABLE (struct efi_get_table_ioc)
             Get a table by uuid from the UEFI system table.

                   struct efi_get_table_ioc {
                           struct uuid uuid;
                           void *ptr;

     EFIIOC_GET_TIME (struct efi_tm)
             Get the time from the RTC, if the RTC is available.  The struct efi_tm passed is
             populated with the current time, unless an error occurs.

                   struct efi_tm {
                           uint16_t        tm_year;
                           uint8_t         tm_mon
                           uint8_t         tm_mday
                           uint8_t         tm_hour;
                           uint8_t         tm_min;
                           uint8_t         tm_sec;
                           uint8_t          __pad1;
                           uint32_t        tm_nsec;
                           int16_t         tm_tz;
                           uint8_t         tm_dst;
                           uint8_t         __pad2;

     EFIIOC_SET_TIME (struct efi_tm)
             Sets the time stored by the RTC, if the RTC is available.

     EFIIOC_VAR_GET (struct efi_var_ioc)
             Gets data from the variable described by the vendor and name fields of the struct
             efi_var_ioc into the data field.  EFIIOC_VAR_GET (struct efi_var_ioc) will also
             populate the attrib field.

             struct efi_var_ioc {
                     efi_char        *name;
                     size_t           namesize;
                     struct uuid      vendor;
                     uint32_t         attrib;
                     void            *data;
                     size_t           datasize;

     EFIIOC_VAR_NEXT (struct efi_var_ioc)
             Used for enumerating all UEFI variables.  The initial call should use an empty
             string for the name attribute.  Subsequent calls should supply the vendor uuid and
             name of the last variable returned.

     EFIIOC_VAR_SET (struct efi_var_ioc)
             Sets data and attributes for the variable described by the name and vendor in the
             struct efi_var_ioc.




     efivar(3), efirt(9)


     A efidev device first appeared in FreeBSD 11.1.


     efidev is currently only available on amd64 and arm64.