all: Rename absolute time-based functions to include "epoch".

For time-based functions that work with absolute time there is the need for
an Epoch, to set the zero-point at which the absolute time starts counting.
Such functions include time.time() and filesystem stat return values.  And
different ports may use a different Epoch.

To make it clearer what functions use the Epoch (whatever it may be), and
make the ports more consistent with their use of the Epoch, this commit
renames all Epoch related functions to include the word "epoch" in their
name (and remove references to "2000").

Along with this rename, the following things have changed:

- mp_hal_time_ns() is now specified to return the number of nanoseconds
  since the Epoch, rather than since 1970 (but since this is an internal
  function it doesn't change anything for the user).

- littlefs timestamps on the esp8266 have been fixed (they were previously
  off by 30 years in nanoseconds).

Otherwise, there is no functional change made by this commit.

Signed-off-by: Damien George <damien@micropython.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/extmod/vfs_lfs.c b/extmod/vfs_lfs.c
index a53f66f2d6..9cf3eb1108 100644
--- a/extmod/vfs_lfs.c
+++ b/extmod/vfs_lfs.c
@@ -26,6 +26,7 @@
 
 #include "py/runtime.h"
 #include "py/mphal.h"
+#include "lib/timeutils/timeutils.h"
 #include "extmod/vfs.h"
 #include "extmod/vfs_lfs.h"
 
@@ -126,7 +127,8 @@ const char *mp_vfs_lfs2_make_path(mp_obj_vfs_lfs2_t *self, mp_obj_t path_in);
 mp_obj_t mp_vfs_lfs2_file_open(mp_obj_t self_in, mp_obj_t path_in, mp_obj_t mode_in);
 
 STATIC void lfs_get_mtime(uint8_t buf[8]) {
-    uint64_t ns = mp_hal_time_ns();
+    // On-disk storage of timestamps uses 1970 as the Epoch, so convert from host's Epoch.
+    uint64_t ns = timeutils_nanoseconds_since_epoch_to_nanoseconds_since_1970(mp_hal_time_ns());
     // Store "ns" to "buf" in little-endian format (essentially htole64).
     for (size_t i = 0; i < 8; ++i) {
         buf[i] = ns;