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>.