[time] Allow system clock to be adjusted at runtime
[ipxe.git] / src / include / ipxe / time.h
1 #ifndef _IPXE_TIME_H
2 #define _IPXE_TIME_H
3
4 /** @file
5 *
6 * Time source
7 *
8 */
9
10 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
11
12 #include <sys/time.h>
13 #include <ipxe/api.h>
14 #include <config/time.h>
15
16 /**
17 * Calculate static inline time API function name
18 *
19 * @v _prefix Subsystem prefix
20 * @v _api_func API function
21 * @ret _subsys_func Subsystem API function
22 */
23 #define TIME_INLINE( _subsys, _api_func ) \
24 SINGLE_API_INLINE ( TIME_PREFIX_ ## _subsys, _api_func )
25
26 /**
27 * Provide a time API implementation
28 *
29 * @v _prefix Subsystem prefix
30 * @v _api_func API function
31 * @v _func Implementing function
32 */
33 #define PROVIDE_TIME( _subsys, _api_func, _func ) \
34 PROVIDE_SINGLE_API ( TIME_PREFIX_ ## _subsys, _api_func, _func )
35
36 /**
37 * Provide a static inline time API implementation
38 *
39 * @v _prefix Subsystem prefix
40 * @v _api_func API function
41 */
42 #define PROVIDE_TIME_INLINE( _subsys, _api_func ) \
43 PROVIDE_SINGLE_API_INLINE ( TIME_PREFIX_ ## _subsys, _api_func )
44
45 /* Include all architecture-independent time API headers */
46 #include <ipxe/null_time.h>
47 #include <ipxe/efi/efi_time.h>
48 #include <ipxe/linux/linux_time.h>
49
50 /* Include all architecture-dependent time API headers */
51 #include <bits/time.h>
52
53 extern signed long time_offset;
54
55 /**
56 * Get current time in seconds (ignoring system clock offset)
57 *
58 * @ret time Time, in seconds
59 */
60 time_t time_now ( void );
61
62 /**
63 * Adjust system clock
64 *
65 * @v delta Clock adjustment, in seconds
66 */
67 static inline __attribute__ (( always_inline )) void
68 time_adjust ( signed long delta ) {
69
70 time_offset += delta;
71 }
72
73 #endif /* _IPXE_TIME_H */