修改内核源代码：
-------------------------------
add pr_*
-------------------------------
pr_emerg("%s: unable to restart system
", __func__);
pr_alert("%s: SGE packet mismatch
", adapter->name);
pr_crit("%s: cannot initialize default policy table: %d
", __func__, err);
pr_err("%s: Couldn't initialize inode slabcache
", __func__);
pr_warn("Freeing alive inet6 address %p
", ifp);
pr_notice("delayed DAD work was pending while freeing ifa=%p
", ifp);
pr_info("%s: use_tempaddr is disabled
", __func__);
pr_debug("%s
", __func__);
-------------------------------
can use printk
-------------------------------
printk(KERN_DEBUG "MPTCP - %s: %d: %s
", __FILE__, __LINE__, __func__ );
printk(KERN_INFO "MPTCP - %s: %d: %s
", __FILE__, __LINE__, __func__ );
// printk("%02x ", data[i]);
// printk("
");
sed -i "s/printk(KERN_DEBUG "MPTCP/printk(KERN_INFO "MPTCP/g" `grep "printk(KERN_DEBUG "MPTCP" -rl ./`
-------------------------------
#define KERN_EMERG "<0>" /* system is unusable*/
#define KERN_ALERT "<1>" /* action must be taken immediately*/
#define KERN_CRIT "<2>" /* critical conditions*/
#define KERN_ERR "<3>" /* error conditions*/
#define KERN_WARNING "<4>" /* warning conditions*/
#define KERN_NOTICE "<5>" /* normal but significant condition*/
#define KERN_INFO "<6>" /* informational*/
#define KERN_DEBUG "<7>" /* debug-level messages*/
-------------------------------
启动 Android，执行下面命令：
//// To determine your current console_loglevel you simply enter:
# cat /proc/sys/kernel/printk
7 4 1 7
current default minimum boot-time-default
//// To change your current console_loglevel simply write to this file,
//// so in orderto get all messages printed to the console do a simple
//// and every kernel message will appear on your console.
# echo 7 > /proc/sys/kernel/printk
or
# dmesg -n 7
cat /proc/kmsg
adb -s 192.168.56.3 shell cat /proc/kmsg