EFIRT(9)               FreeBSD Kernel Developer's Manual              EFIRT(9)

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(enum efi_reset type);

     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 reset of the system.  The type
     argument may be one of the enum efi_reset values:

     EFI_RESET_COLD          Perform a cold reset of the system, and reboot.

     EFI_RESET_WARM          Perform a warm reset of the system, and reboot.

     EFI_RESET_SHUTDOWN      Power off 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 variable 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>.

FreeBSD 13.1-RELEASE-p6        November 2, 2021        FreeBSD 13.1-RELEASE-p6