换Log输出的UART口

1. 查看uboot配置

以x2000_darwin_factory_defconfig编译配置为例

bhu@bhu-PC:~/work/build$ grep -nr "uboot_" configs/x2000_darwin_factory_defconfig           //查看uboot配置
3:APP_uboot_toolchain_dir=../tools/toolchains/mips-gcc720-glibc229
4:APP_uboot_dir=../bootloader/uboot-x2000
5:APP_uboot_config=x2000_base_xImage_sfc_nand                                              //uboot配置文件

在bootloader/uboot-x2000目录下的boards.cfg文件搜索uboot配置

bhu@bhu-PC:~/work/build$ grep -nr "x2000_base_xImage_sfc_nand" ../bootloader/uboot-x2000/boards.cfg 
679:x2000_base_xImage_sfc_nand   mips        xburst2    x2000_base       ingenic        x2000_v12       x2000_base:SPL_SFC_NAND,MTD_SFCNAND,SPL_OS_BOOT,RMEM_MB=16,SPL_PARAMS_FIXER

2. 修改uboot配置

可以看到使用的配置是x2000_base,在x2000_base:后面可以设置打印uart口,格式为SYS_UART_INDEX=x,不添加默认使用x2000_base的

x2000_base.h位于bootloader/uboot-x2000/include/configs

#ifndef __X2000_BASE_H__
#define __X2000_BASE_H__

#define CONFIG_ROOTFS_SQUASHFS
#define CONFIG_ROOTFS2_SQUASHFS
#define CONFIG_ARG_QUIET                 //去掉这个可以打开所有系统打印信息
#define CONFIG_SPL_SERIAL_SUPPORT

#include "x2000_base_common.h"          //实际配置

#endif /* __X2000_BASE_H__ */

实际配置在同一目录下,可以对uart口及波特率进行修改，这里uart口的设置优先级小于前面x2000_base:后面设置的

/*

 * uart setting
   */
   #ifndef CONFIG_SYS_UART_INDEX
   #define CONFIG_SYS_UART_INDEX   2              //uart口
   #endif

#ifndef CONFIG_BAUDRATE
#define CONFIG_BAUDRATE     3000000              //波特率
#endif

3. 问题排查

若无串口输出，查看uart口和波特率是否与配置一致，新增串口需要在kernel中添加

以x2000_darwin_factory_defconfig编译配置为例，查看kernel中关于uart的配置

bhu@bhu-PC:~/work/build$ grep -nr "kernel" configs/x2000_darwin_factory_defconfig      //先查看kernel的配置
6:APP_kernel_dir=../kernel/kernel-x2000
7:APP_kernel_config=x2000_module_base_linux_sfc_nand_defconfig                         //kernel配置文件

配置文件位于kernel/kernel-x2000/arch/mips/configs目录下

bhu@bhu-PC:~/work/kernel/kernel-x2000/arch/mips/configs$ grep -nr ".dts"  ./x2000_module_base_linux_sfc_nand_defconfig

88:CONFIG_DT_X2000_MODULE_BASE_DTS_FILE="x2000_module_base.dts"                  //关于uart配置

x2000_module_base.dts位于kernel/kernel-x2000/arch/mips/boot/dts/ingenic目录下,可以对需要用到的串口进行添加修改

#include <dt-bindings/input/input.h>
#include "x2000.dtsi"
#include <dt-bindings/interrupt-controller/irq.h>
#include <generated/autoconf.h>

/ {
    compatible = "ingenic,x2000_module_base", "ingenic,x2000";
};

&uart2 {
    status = "okay";
    pinctrl-names = "default";
    pinctrl-0 = <&uart2_pd>;
};

&uart3 {
    status = "okay";
    pinctrl-names = "default";
    pinctrl-0 = <&uart3_pd>;
};

参考串⼝引脚定义在kernel/kernel-x2000/arch/mips/boot/dts/ingenic目录下的x2000-pinctrl.dtsi文件

#include <dt-bindings/pinctrl/ingenic-pinctrl.h>

&pinctrl {
    uart0_pin: uart0-pin {
        uart0_pd: uart0-pd {
            ingenic,pinmux = <&gpd 23 26>;
            ingenic,pinmux-funcsel = <PINCTL_FUNCTION2>;
        };
    };
    uart1_pin: uart1-pin {
        uart1_pc: uart1-pc {
            ingenic,pinmux = <&gpc 21 24>;
            ingenic,pinmux-funcsel = <PINCTL_FUNCTION1>;
        };
    };

uart2_pin: uart2-pin {
    uart2_pd: uart2-pd {
        ingenic,pinmux = <&gpd 30 31>;
        ingenic,pinmux-funcsel = <PINCTL_FUNCTION0>;
    };
};

uart3_pin: uart3-pin {
    uart3_pc: uart3-pc {
        ingenic,pinmux = <&gpc 25 26>;
        ingenic,pinmux-funcsel = <PINCTL_FUNCTION0>;
    };
    uart3_pd: uart3-pd {
        ingenic,pinmux = <&gpd 0 3>;
        ingenic,pinmux-funcsel = <PINCTL_FUNCTION1>;
    };
};