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freebsd/lib/libefivar/efivar.3
Warner Losh d49a5ddd04 Create libefivar library. This library aims to provide
the same API as the GPL'd version of this library. It implements the common
Linux API for programatically manipulating UEFI environment varibales using
the UEFI Runtime Services the kernel provides. It replaces the old efi
library since it is programmed to a different interface, but retails the
CHAR16 to UTF-8 and vice versa conversion routines. The new name is to match
Linux program's expectations.

Differential Revision: https://reviews.freebsd.org/D8128
Reviewed by: kib@, wblock@, Ganael Laplanche
2016-10-11 22:30:41 +00:00

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3.5 KiB
Groff

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.Dd September 14, 2016
.Dt LIBEFIVAR 3
.Os
.Sh NAME
.Nm libefivar
.Nd EFI Non Volatile Variable Suppoert
.Sh SYNOPSIS
.In efivar.h
.Ft int
.Fn efi_append_variable "efi_guid_t guid" "const char *name" "void *data" "size_t data_size" "uint32_t attributes"
.Ft int
.Fn efi_del_variable "efi_guid_t guid" "const char *name"
.Ft int
.Fn efi_get_variable "efi_guid_t guid" "const char *name" "void **data" "ssize_t *data_size" "uint32_t *attributes"
.Ft int
.Fn efi_get_variable_attributes "efi_guid_t guid" "const char *name" "uint32_t *attributes"
.Ft int
.Fn efi_get_variable_size "efi_guid_t guid" "const char *name" "size_t *size"
.Ft int
.Fn efi_get_next_variable_name "efi_guid_t **guid" "char **name"
.Ft int
.Fn efi_guid_to_name "efi_guid_t *guid" "char **name"
.Ft int
.Fn efi_guid_to_symbol "efi_guid_t *guid" "char **symbol"
.Ft int
.Fn efi_guid_to_str "const efi_guid_t *guid" "char **sp"
.Ft int
.Fn efi_name_to_guid "const char *name" "efi_guid_t *guid"
.Ft int
.Fn efi_set_variable "efi_guid_t guid" "const char *name" "void *data" "size_t data_size" "uint32_t attributes"
.Ft int
.Fn efi_str_to_guid "const char *s" "efi_guid_t *guid";
.Ft int
.Fn efi_variables_supported "void";
.Sh DESCRIPTION
The
.Nm
library implements access to EFI Variables via the EFI Runtime
Serivces.
All char * strings are converted to 16-bit UTF strings before passing
them to EFI.
.Pp
.Fn 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.
.Pp
.Fn efi_del_variable
deletes the EFI variable selected by
.Dv guid
and
.Dv name .
.Pp
.Fn efi_get_variable
.Fn efi_get_variable_attributes
.Fn efi_get_variable_size
.Fn efi_append_variable
.Fn efi_set_variable
.Fn efi_get_next_variable_name
.Fn efi_str_to_guid
.Fn efi_guid_to_str
.Fn efi_name_to_guid
.Fn efi_guid_to_name
.Fn efi_guid_to_symbol
This function is not actually implemented.
.Sh BUGS
No facilities exist to process the strings as native UTF.
This is a limitation in the Linux libefivar library interface.
.Sh AUTHORS
.An -nosplit
This software was originally written by
.An Warner Losh .