xref: /xnu-12377.41.6/bsd/sys/preoslog.h (revision bbb1b6f9e71b8cdde6e5cd6f4841f207dee3d828)
1 /*
2  * Copyright (c) 2021-2022 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
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12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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18  * The Original Code and all software distributed under the License are
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20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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27  */
28 
29 #ifndef _SYS_PREOSLOG_H_
30 #define _SYS_PREOSLOG_H_
31 
32 #include <sys/cdefs.h>
33 
34 __BEGIN_DECLS
35 
36 #define PREOSLOG_MAGIC 'LSOP'
37 #define PREOSLOG_SYSCTL "kern.preoslog"
38 
39 typedef uint8_t preoslog_source_t;
40 enum {
41 	PREOSLOG_SOURCE_IBOOT = 0,
42 	PREOSLOG_SOURCE_MACEFI,
43 	PREOSLOG_SOURCE_MAX
44 };
45 
46 /*
47  * Any change to this structure must be reflected in boot loader (iboot / xnu SDK header) and vice versa.
48  * Beware: if you remove __attribute__((packed)) here, then sizeof() on this structure will return 16.
49  * However, with or without __attribute__((packed)), offset_of(preoslog_header_t, data) will always return 14.
50  */
51 
52 typedef struct  __attribute__((packed)) {
53 	uint32_t magic; /* PREOGLOS_MAGIC if valid */
54 	uint32_t size; /* Size of the preoslog buffer including the header */
55 	uint32_t offset; /* Write pointer. Indicates where in the buffer new log entry would go */
56 	preoslog_source_t source; /* Indicates who filled in the buffer (e.g. iboot vs MacEFI) */
57 	uint8_t wrapped; /* If equal to 1, the preoslog ring buffer wrapped at least once */
58 	char data[]; /* log buffer */
59 } preoslog_header_t;
60 
61 __END_DECLS
62 
63 #endif  /* !_SYS_PREOSLOG_H_ */
64