如何在Android user 版本下打開UART log？

[DESCRIPTION]
如何在Android user版本下打開UART log?

[KEYWORD]
user version kernel log

[SOLUTION]
爲了加快運行速度，在user版本中關閉了UART log.

如果爲了調試

1. 打開一個文件:

alps/mediatek/config/common/autoconfig/kconfig/USER

查看是否存在CONFIG_COMLINE=”console=ttyMT3,921600n1 loglevel=0”，如果存在，則把loglevel=0修改爲loglevel = 8

然後

./mk n k

./mk bootimage

 

2. 如不存在CONFIG_COMMLINE，則查看alps/bootable/bootloader/lk/app/mt_boot/mt_boot.c的boot_linux()函數：

if (!has_set_p2u) {
#ifdef USER_BUILD
    sprintf(cmdline,"%s%s",cmdline," printk.disable_uart=1");
#else
    sprintf(cmdline,"%s%s",cmdline," printk.disable_uart=0");
#endif
}

修改爲：

if (!has_set_p2u) {
#ifdef USER_BUILD
    sprintf(cmdline,"%s%s",cmdline," printk.disable_uart=0 ignore_loglevel");
#else
    sprintf(cmdline,"%s%s",cmdline," printk.disable_uart=0");
#endif
}