xref: /freebsd/lib/libefivar/efivar-dp.h (revision 1c05a6ea6b849ff95e539c31adea887c644a6a01)
1 /*-
2  * Copyright (c) 2017 Netflix, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef	_EFIVAR_DP_H_
30 #define	_EFIVAR_DP_H_
31 
32 /*
33  * "Linux compatible" efivar-dp.h header. At the moment, it's really a
34  * very thin, minimal interface.
35  */
36 
37 /*
38  * Generic EFI_DEVICE_PATH, spelled the Linux way. We use this
39  * interface to the outside world and type-pun to the EFI EDK2 code
40  * we use to implement it.
41  */
42 typedef struct {
43 	uint8_t type;
44 	uint8_t subtype;
45 	uint16_t length;
46 } __packed efidp_header;
47 
48 /* NB: Linux has shadow types for all dp type */
49 
50 typedef union {
51         efidp_header header;
52 } efidp_data;
53 typedef efidp_data *efidp;
54 typedef const efidp_data *const_efidp;
55 
56 /** format a device path into UEFI standard conforming output.
57  *
58  * NB: FreeBSD's implementation is taken from EDK2, while Linux's
59  * was hand-rolled. There may be differences as a result.
60  */
61 ssize_t efidp_format_device_path(char *buf, size_t len, const_efidp dp,
62     ssize_t max);
63 ssize_t efidp_parse_device_path(char *path, efidp out, size_t max);
64 
65 size_t efidp_size(const_efidp);
66 
67 #endif /* _EFIVAR_DP_H_ */
68