1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
apps/system/zoninfo/README.txt
Author: Gregory Nutt <gnutt@nuttx.org>
Directory Contents
==================
This directory contains logic to create a version of the TZ/Olson database.
This database is required if localtime() support is selected via
CONFIG_LIBC_LOCALTIME. This logic in this directory does the following:
- It downloads the current TZ database from the IANA website
- It downloads the current timezone tools from the same location
- It builds the tools and constructs the binary TZ database
- It will then, optionally, build a ROMFS filesystem image containing
the data base.
Creating and Mounting a ROMFS TZ Database
=========================================
The ROMFS filesystem image can that be mounted during the boot-up sequence
so that it is available for the localtime() logic. There are two steps to
doing this:
- First, a ROM disk device must be created. This is done by calling
the function romdisk_register() as described in
nuttx/include/nuttx/fs/ramdisk.h. This is an OS level operation
and must be done in the board-level logic before your application
starts.
romdisk_register() will create a block driver at /dev/ramN where N
is the device minor number that was provided to romdisk_regsiter.
- The second step is to mount the file system. This step can be
performed either in your board configuration logic or by your
application using the mount() interface described in
nuttx/include/sys/mount.h.
These steps, however, must be done very early in initialization,
before there is any need for time-related services.
Both of these steps are shown together in the following code sample at the
end of this README file.
Example Configuration
=====================
I have tested this using the sim/nsh configuration. Here are the
modifications to the configuration that I used for testing:
CONFIG_BOARD_INITIALIZE=y
CONFIG_LIBC_LOCALTIME=y
CONFIG_LIBC_TZDIR="/share/zoneinfo"
CONFIG_LIBC_TZ_MAX_TIMES=370
CONFIG_LIBC_TZ_MAX_TYPES=20
CONFIG_SYSTEM_ZONEINFO=y
CONFIG_SYSTEM_ZONEINFO_ROMFS=y
NOTE: The full TZ database is quite large. To create a reasonable sized
ROMFS image, I had to trim some of the files like this:
make context
cd ../apps/system/zoneinfo/tzbin/etc/zoneinfo
Remove as many timezone files as you can. Do not remove the GMT, localtime,
or posixrules files. Those might be needed in any event. Then you can
force rebuilding of the ROMFS filesystem be removing some files:
cd ../../..
rm romfs_zoneinfo.*
rm *.o
cd ../../nuttx
make
Here is a sample run. I have not seen any errors in single stepping through
the logic but neither am I certain that everything is working properly:
NuttShell (NSH)
nsh> date
Jul 01 00:00:02 2008
nsh> set TZ US/Mountain
nsh> date -s "Apr 11 11:53:00 2015"
nsh> date
Apr 11 17:53:00 2015
Sample Code to Mount the ROMFS Filesystem
=========================================
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/mount.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <nuttx/fs/ramdisk.h>
#include <apps/zoneinfo.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_LIBC_TZDIR
# errror CONFIG_LIBC_TZDIR is not defined
#endif
#ifdef CONFIG_DISABLE_MOUNTPOINT
# error "Mountpoint support is disabled"
#endif
#if CONFIG_NFILE_DESCRIPTORS < 4
# error "Not enough file descriptors"
#endif
#ifndef CONFIG_FS_ROMFS
# error "ROMFS support not enabled"
#endif
#define SECTORSIZE 64
#define NSECTORS(b) (((b)+SECTORSIZE-1)/SECTORSIZE)
/****************************************************************************
* Public Functions
****************************************************************************/
int mount_zoneinfo(int minor)
{
char devname[32];
int ret;
/* Create a RAM disk for the test */
ret = romdisk_register(minor, romfs_zoneinfo_img,
NSECTORS(romfs_zoneinfo_img_len), SECTORSIZE);
if (ret < 0)
{
printf("ERROR: Failed to create RAM disk\n");
return ret;
}
/* Use the minor number to create a name for the ROM disk block device */
snprintf(devname, 32, "/dev/ram%d", minor);
/* Mount the ROMFS file system */
printf("Mounting ROMFS filesystem at target=%s with source=%s\n",
CONFIG_LIBC_TZDIR, devname);
ret = mount(devname, CONFIG_LIBC_TZDIR, "romfs", MS_RDONLY, NULL);
if (ret < 0)
{
printf("ERROR: Mount failed: %d\n", errno);
return ret;
}
printf("TZ database mounted at %s\n", CONFIG_LIBC_TZDIR);
return OK;
}
|
