NAME

       efirt, efi_rt_ok, efi_get_table, efi_get_time, efi_get_time_capabilities, efi_reset_system, efi_set_time,
       efi_var_get, efi_var_nextname, efi_var_set — kernel access to UEFI runtime services

SYNOPSIS

       options EFIRT

       #include <sys/efi.h>

       int
       efi_rt_ok(void);

       int
       efi_get_table(struct uuid *uuid, void **ptr);

       int
       efi_get_time(struct efi_tm *tm);

       int
       efi_get_time_capabilities(struct efi_tmcap *tmcap);

       int
       efi_reset_system(void);

       int
       efi_set_time(struct efi_tm *tm);

       int
       efi_var_get(uint16_t *name, struct uuid *vendor, uint32_t *attrib, size_t *datasize, void *data);

       int
       efi_var_nextname(size_t *namesize, uint16_t *name, struct uuid *vendor);

       int
       efi_var_set(uint16_t *name, struct uuid *vendor, uint32_t *attrib, size_t *datasize, void *data);

DESCRIPTION

       All  of  the  following  calls  will  return  ENXIO if UEFI runtime services are not available.  efirt is
       currently only available on amd64 and arm64.

       The efi_rt_ok() Returns 0 if UEFI runtime services are present and functional, or ENXIO if not.

       The efi_get_table() function gets a table by uuid from the UEFI system table.  Returns 0 if the table was
       found and populates *ptr with the address.  Returns ENXIO if the configuration table or system table  are
       unset.  Returns ENOENT if the requested table cannot be found.

       The  efi_get_time()  function  gets the current time from the RTC, if available.  Returns 0 and populates
       the struct efi_tm on success.  Returns EINVAL if the struct efi_tm is NULL, or EIO if the time could  not
       be retrieved due to a hardware error.

       The efi_get_time_capabilities() function gets the capabilities from the RTC.  Returns 0 and populates the
       struct  efi_tmcap  on success.  Returns EINVAL if the struct efi_tm is NULL, or EIO if the time could not
       be retrieved due to a hardware error.

       The efi_reset_system() function requests a warm reset and reboot of the system.

       The efi_set_time() function sets the time on the RTC to the time described by the  struct  efi_tm  passed
       in.   Returns  0  on success, EINVAL if a time field is out of range, or EIO if the time could not be set
       due to a hardware error.

       The efi_var_get() function fetches the variable identified by vendor and name.  Returns 0  and  populates
       attrib, datasize, and data on success.  Otherwise, one of the following errors are returned:

       ENOENT     The variable was not found.

       EOVERFLOW  datasize is not sufficient to hold the variable data.  namesize is updated to reflect the size
                  needed to complete the request.

       EINVAL     One  of  name,  vendor, or datasize are NULL.  Alternatively, datasize is large enough to hold
                  the response but data is NULL.

       EIO        The variable could not be retrieved due to a hardware error.

       EDOOFUS    The variable could not be retireved due to an authentication failure.

       The efi_var_nextname()  function  is  used  for  enumeration  of  variables.   On  the  initial  call  to
       efi_var_nextname(),  name  should  be an empty string.  Subsequent calls should pass in the last name and
       vendor returned until ENOENT is returned.  Returns 0 and populates namesize, name, and  vendor  with  the
       next variable's data.  Otherwise, returns one of the following errors:

       ENOENT     The next variable was not found.

       EOVERFLOW  datasize is not sufficient to hold the variable data.  namesize is updated to reflect the size
                  needed to complete the request.

       EINVAL     One of name, vendor, or datasize are NULL.

       EIO        The variable could not be retrieved due to a hardware error.

       The efi_var_set() function sets the variable described by name and vendor.  Returns 0 if the variable has
       been successfully.  Otherwise, returns one of the following errors:

       EINVAL     Either  attrib  was an invalid combination of attributes, datasize exceeds the maximum allowed
                  size, or name is an empty Unicode stirng.

       EAGAIN     Not enough storage is available to hold the variable and its data.

       EIO        The variable could not be saved due to a hardware error.

       EROFS      The variable in question is read-only or may not be deleted.

       EDOOFUS    The varialbe could not be set due to an authentication failure.

       ENOENT     The variable trying to be updated or deleted was not found.

SEE ALSO

       efidev(4)

AUTHORS

       This manual page was written by Kyle Evans <kevans@FreeBSD.org>.

Debian                                           August 12, 2018                                        EFIRT(9)