xref: /freebsd/lib/libefivar/efivar-dp.h (revision b3e76948)
1 /*-
2  * Copyright (c) 2017 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #ifndef	_EFIVAR_DP_H_
27 #define	_EFIVAR_DP_H_
28 
29 /*
30  * "Linux compatible" efivar-dp.h header. At the moment, it's really a
31  * very thin, minimal interface.
32  */
33 
34 /*
35  * Generic EFI_DEVICE_PATH, spelled the Linux way. We use this
36  * interface to the outside world and type-pun to the EFI EDK2 code
37  * we use to implement it.
38  */
39 typedef struct {
40 	uint8_t type;
41 	uint8_t subtype;
42 	uint16_t length;
43 } __packed efidp_header;
44 
45 /* NB: Linux has shadow types for all dp type */
46 
47 typedef union {
48         efidp_header header;
49 } efidp_data;
50 typedef efidp_data *efidp;
51 typedef const efidp_data *const_efidp;
52 
53 /** format a device path into UEFI standard conforming output.
54  *
55  * NB: FreeBSD's implementation is taken from EDK2, while Linux's
56  * was hand-rolled. There may be differences as a result.
57  */
58 ssize_t efidp_format_device_path(char *buf, size_t len, const_efidp dp,
59     ssize_t max);
60 ssize_t efidp_format_device_path_node(char *buf, size_t len, const_efidp dp);
61 ssize_t efidp_parse_device_path(char *path, efidp out, size_t max);
62 char * efidp_extract_file_path(const_efidp dp);
63 
64 size_t efidp_size(const_efidp);
65 
66 int efivar_device_path_to_unix_path(const_efidp dp, char **dev, char **relpath, char **abspath);
67 int efivar_unix_path_to_device_path(const char *path, efidp *dp);
68 
69 #endif /* _EFIVAR_DP_H_ */
70