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#include <arch/i386/tsc.h>
#include <drivers/cmos.h>
#include <fs/devfs.h>
#include <math.h>
#include <time.h>
#include <typedefs.h>
i64 start_unix_time;
u64 start_tsc_time;
void timer_init(void) {
tsc_init();
start_tsc_time = tsc_get();
start_unix_time = cmos_get_time();
}
u64 timer_get_uptime(void) {
return tsc_calculate_ms(tsc_get());
}
void timer_get(struct timespec *tp) {
u64 offset_tsc = tsc_get() - start_tsc_time;
i64 current_unix_time_seconds =
start_unix_time + tsc_calculate_ms(offset_tsc) / 1000;
tp->tv_sec = current_unix_time_seconds;
tp->tv_nsec = tsc_calculate_ms(offset_tsc);
}
u64 timer_get_ms(void) {
u64 offset_tsc = tsc_get() - start_tsc_time;
return start_unix_time * 1000 + tsc_calculate_ms(offset_tsc);
}
int clock_read(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
(void)offset;
u64 r = timer_get_ms();
u64 l = min(len, sizeof(u64));
memcpy(buffer, &r, l);
return l;
}
int clock_write(u8 *buffer, u64 offset, u64 len, vfs_fd_t *fd) {
(void)offset;
if (len != sizeof(i64)) {
return 0;
}
i64 new_value_ms;
memcpy(&new_value_ms, buffer, sizeof(i64));
i64 new_value_seconds = new_value_ms / 1000;
u64 offset_tsc = tsc_get() - start_tsc_time;
i64 current_unix_time_seconds =
start_unix_time + tsc_calculate_ms(offset_tsc) / 1000;
i64 delta = new_value_seconds - current_unix_time_seconds;
start_unix_time += delta;
cmos_set_time(new_value_seconds);
return sizeof(i64);
}
int always_has_data(vfs_inode_t *inode);
int always_can_write(vfs_inode_t *inode);
int timer_add_clock(void) {
devfs_add_file("/clock", clock_read, clock_write, NULL, always_has_data,
always_can_write, FS_TYPE_CHAR_DEVICE);
return 1;
}
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