Add a "fork" of musl as //fusl.

fusl/include/sys/timex.h

+#ifndef _SYS_TIMEX_H
+#define _SYS_TIMEX_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define __NEED_clockid_t
+
+#include <bits/alltypes.h>
+
+#include <sys/time.h>
+
+struct ntptimeval {
+        struct timeval time;
+        long maxerror, esterror;
+};
+
+struct timex {
+        unsigned modes;
+        long offset, freq, maxerror, esterror;
+        int status;
+        long constant, precision, tolerance;
+        struct timeval time;
+        long tick, ppsfreq, jitter;
+        int shift;
+        long stabil, jitcnt, calcnt, errcnt, stbcnt;
+        int tai;
+        int __padding[11];
+};
+
+#define ADJ_OFFSET              0x0001
+#define ADJ_FREQUENCY           0x0002
+#define ADJ_MAXERROR            0x0004
+#define ADJ_ESTERROR            0x0008
+#define ADJ_STATUS              0x0010
+#define ADJ_TIMECONST           0x0020
+#define ADJ_TAI                 0x0080
+#define ADJ_SETOFFSET           0x0100
+#define ADJ_MICRO               0x1000
+#define ADJ_NANO                0x2000
+#define ADJ_TICK                0x4000
+#define ADJ_OFFSET_SINGLESHOT   0x8001
+#define ADJ_OFFSET_SS_READ      0xa001
+
+#define MOD_OFFSET      ADJ_OFFSET
+#define MOD_FREQUENCY   ADJ_FREQUENCY
+#define MOD_MAXERROR    ADJ_MAXERROR
+#define MOD_ESTERROR    ADJ_ESTERROR
+#define MOD_STATUS      ADJ_STATUS
+#define MOD_TIMECONST   ADJ_TIMECONST
+#define MOD_CLKB        ADJ_TICK
+#define MOD_CLKA        ADJ_OFFSET_SINGLESHOT
+#define MOD_TAI         ADJ_TAI
+#define MOD_MICRO       ADJ_MICRO
+#define MOD_NANO        ADJ_NANO
+
+#define STA_PLL         0x0001
+#define STA_PPSFREQ     0x0002
+#define STA_PPSTIME     0x0004
+#define STA_FLL         0x0008
+
+#define STA_INS         0x0010
+#define STA_DEL         0x0020
+#define STA_UNSYNC      0x0040
+#define STA_FREQHOLD    0x0080
+
+#define STA_PPSSIGNAL   0x0100
+#define STA_PPSJITTER   0x0200
+#define STA_PPSWANDER   0x0400
+#define STA_PPSERROR    0x0800
+
+#define STA_CLOCKERR    0x1000
+#define STA_NANO        0x2000
+#define STA_MODE        0x4000
+#define STA_CLK         0x8000
+
+#define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER | \
+    STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
+
+#define TIME_OK         0
+#define TIME_INS        1
+#define TIME_DEL        2
+#define TIME_OOP        3
+#define TIME_WAIT       4
+#define TIME_ERROR      5
+#define TIME_BAD        TIME_ERROR
+
+#define MAXTC           6
+
+int adjtimex(struct timex *);
+int clock_adjtime(clockid_t, struct timex *);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif