LIBEFIVAR(3)           FreeBSD Library Functions Manual           LIBEFIVAR(3)

NAME
     libefivar - EFI Non Volatile Variable Support

SYNOPSIS
     #include <efivar.h>

     int
     efi_append_variable(efi_guid_t guid, const char *name, void *data,
         size_t data_size, uint32_t attributes);

     int
     efi_del_variable(efi_guid_t guid, const char *name);

     int
     efi_get_variable(efi_guid_t guid, const char *name, void **data,
         ssize_t *data_size, uint32_t *attributes);

     int
     efi_get_variable_attributes(efi_guid_t guid, const char *name,
         uint32_t *attributes);

     int
     efi_get_variable_size(efi_guid_t guid, const char *name, size_t *size);

     int
     efi_get_next_variable_name(efi_guid_t **guid, char **name);

     int
     efi_guid_to_name(efi_guid_t *guid, char **name);

     int
     efi_guid_to_symbol(efi_guid_t *guid, char **symbol);

     int
     efi_guid_to_str(const efi_guid_t *guid, char **sp);

     int
     efi_name_to_guid(const char *name, efi_guid_t *guid);

     int
     efi_set_variable(efi_guid_t guid, const char *name, void *data,
         size_t data_size, uint32_t attributes);

     int
     efi_str_to_guid(const char *s, efi_guid_t *guid);

     int
     efi_variables_supported(void);

DESCRIPTION
     The libefivar library implements access to EFI Variables via the EFI
     Runtime Services.  All char * strings are converted to 16-bit UTF strings
     before passing them to EFI.

     efi_variables_supported() returns non-zero if the current machine
     supports setting of EFI firmware variables and the kernel support for
     doing so is present.  Otherwise zero is returned.

     efi_del_variable() deletes the EFI variable selected by guid and name.

     The following functions have not been implemented yet:
           -   efi_append_variable()
           -   efi_get_next_variable_name()
           -   efi_get_variable()
           -   efi_get_variable_attributes()
           -   efi_get_variable_size()
           -   efi_guid_to_name()
           -   efi_guid_to_str()
           -   efi_guid_to_symbol()
           -   efi_name_to_guid()
           -   efi_set_variable()
           -   efi_str_to_guid()

SEE ALSO
     efidev(4)

HISTORY
     The libefivar library first appeared in FreeBSD 12.0.

AUTHORS
     This software was originally written by Warner Losh.

BUGS
     No facilities exist to process the strings as native UTF.  This is a
     limitation in the Linux libefivar library interface.

FreeBSD 13.1-RELEASE-p6        October 25, 2018        FreeBSD 13.1-RELEASE-p6