一般情况下,RK系列主板的ttyS2(即uart2)基本都是设计为debug调试口, 提供fiq debugger功能。
将调试口更改为普通串口,具体修改如下:
- 移除掉kernel里的fiq debugger驱动:
//dts中disabled掉fiq debugger驱动节点
fiq-debugger {
compatible = "rockchip,fiq-debugger";
interrupts = <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>;
rockchip,serial-id = <2>;
rockchip,wake-irq = <0>;
rockchip,irq-mode-enable = <0>; /* If enable uart uses irq instead of fiq */
rockchip,baudrate = <115200>; /* Only 115200 and 1500000 */
pinctrl-names = "default";
pinctrl-0 = <&uart2_xfer>;
+ status = "disabled";
};
//或者注释掉kernel config里的FIQ_DEBUGGER相关配置
#CONFIG_FIQ_DEBUGGER=y
#CONFIG_FIQ_DEBUGGER_NO_SLEEP=y
#CONFIG_FIQ_DEBUGGER_CONSOLE=y
#CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE=y
#CONFIG_FIQ_DEBUGGER_TRUST_ZONE=y
- 打开uart2(由于之前做调试串口需要关闭):
&uart2 {
- status = "disabled";
+ status = "okay";
};
- 删除bootargs:
chosen {
- bootargs = "earlycon=uart8250,mmio32,0xff690000 vmalloc=496M";
+ //bootargs = "earlycon=uart8250,mmio32,0xff690000 vmalloc=496M";
};
- 修改parameter.txt(去掉 ttyFIQ0):
-CMDLINE: console=ttyFIQ0 androidboot.baseband
+CMDLINE: console= androidboot.baseband
- device/rockchip/common/recovery/etc/init.rc文件中 移除console:
service recovery /sbin/recovery
- console
+ #console
seclabel u:r:recovery:s0
修改编译烧录后,ttyS2即可作为普通串口使用,短接TX,RX可自发自收!