| /* rtc_get_time_ms.c - get_time_ms implementation using platform RTC. |
| * The generic implementation of these functions can be used for architectures |
| * or platforms that do not have a more specialized implementation. */ |
| /* |
| * GRUB -- GRand Unified Bootloader |
| * Copyright (C) 2008 Free Software Foundation, Inc. |
| * |
| * GRUB is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, either version 3 of the License, or |
| * (at your option) any later version. |
| * |
| * GRUB is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with GRUB. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <grub/time.h> |
| #include <grub/misc.h> |
| #include <grub/machine/time.h> |
| |
| /* Calculate the time in milliseconds since the epoch based on the RTC. */ |
| grub_uint64_t |
| grub_rtc_get_time_ms (void) |
| { |
| /* By dimensional analysis: |
| |
| 1000 ms N rtc ticks 1 s |
| ------- * ----------- * ----------- = 1000*N/T ms |
| 1 s 1 T rtc ticks |
| */ |
| grub_uint64_t ticks_ms_per_sec = ((grub_uint64_t) 1000) * grub_get_rtc (); |
| return grub_divmod64 (ticks_ms_per_sec, GRUB_TICKS_PER_SECOND ? : 1000, 0); |
| } |
