拨号: *#*#2846579#*#*
会显示工程菜单,
Go to "ProjectMenu" -> "Background Setting" -> "Log Setting"
Open "Log switch" and set it to ON.
Open "Log level setting" and set the log level you wish.
重启手机(检查display -> fastboot, 务必要关掉)
如果不行... 再重启一次
这是因为华为默认禁掉了log输出, 解决办法:
拨号: *#*#2846579#*#*
会显示工程菜单,
Go to "ProjectMenu" -> "Background Setting" -> "Log Setting"
Open "Log switch" and set it to ON.
Open "Log level setting" and set the log level you wish.
重启手机(检查display -> fastboot, 务必要关掉)
如果不行... 再重启一次使用华为U8860测试时出现“Unable to open log device '/dev/log/main': No such file or directory”
原文：http://www.cnblogs.com/milton/p/4230040.html