arm linux-----时钟时区设置

参考资料

https://blog.csdn.net/wavemcu/article/details/29375363

http://www.voidcn.com/article/p-tstodgag-bsb.html

配置方法

1. 添加timezone文件
   将PC端的/usr/share/zoneinfo整个zoneinfo文件夹复制到ROOTFS的/usr/share下，这样嵌入式系统中就有了timezone。

root@imx6ul:~# ls /usr/share/zoneinfo/Asia/Shanghai
/usr/share/zoneinfo/Asia/Shanghai

2. 修改系统UTC 标记为 CST
   UTC=no

root@imx6ul:~# cat /etc/default/rcS 
#
#       Defaults for the boot scripts in /etc/rcS.d
#

# Time files in /tmp are kept in days.
TMPTIME=0
# Set to yes if you want sulogin to be spawned on bootup
SULOGIN=no
# Set to no if you want to be able to login over telnet/rlogin
# before system startup is complete (as soon as inetd is started)
DELAYLOGIN=no
# Assume that the BIOS clock is set to UTC time (recommended)
UTC=no
# Set VERBOSE to "no" if you would like a more quiet bootup.
VERBOSE=no
# Set EDITMOTD to "no" if you don't want /etc/motd to be edited automatically
EDITMOTD=no
# Whether to fsck root on boot
ENABLE_ROOTFS_FSCK=no
# Set FSCKFIX to "yes" if you want to add "-y" to the fsck at startup.
FSCKFIX=yes
# Set TICKADJ to the correct tick value for this specific machine
#TICKADJ=10000
# Enable caching in populate-volatile.sh
VOLATILE_ENABLE_CACHE=yes
# Indicate whether the rootfs is intended to be read-only or not.
# Setting ROOTFS_READ_ONLY to yes and rebooting will give you a read-only rootfs.
# Normally you should not change this value.
ROOTFS_READ_ONLY=no

3. 系统RTC硬件时钟注意事项

# hwclock -w  //  默认是指本地时钟写入到硬件时钟
# hwclock -r   //  默认是按照本地时钟显示