【FAQ】全志R329如何通过uboot修改设备树属性？

[q1215200171]

问题背景

硬件：R328+ Wi-Fi模组（XRADIO）
软件：Tina3.0及以上

问题简述

有时候经常需要临时调整部份设备树的属性配置，例如sdc的频率，以太网的delay参数。如果每次都源码修改后编译烧写，比较费时，所以uboot提供了临时修改的方法。
注：uboot修改都是单次启动有效，重启无效。

问题分析

1.修改sdc的属性

产看当前sdc的配置

=> fdt print /soc/sdmmc@4021000
sdmmc@4021000 {
        compatible = "allwinner,sunxi-mmc-v5p3x";
        device_type = "sdc1";
        reg = <0x00000000 0x04021000 0x00000000 0x00001000>;
        interrupts = <0x00000000 0x00000029 0x00000004>;
        clocks = <0x0000000c 0x00000002 0x00000005 0x00000002 0x0000003a 0x00000002 0x0000003d>;
        clock-names = "osc24m", "pll_periph", "mmc", "ahb";
        resets = <0x00000002 0x00000010>;
        reset-names = "rst";
        pinctrl-names = "default", "sleep";
        pinctrl-0 = <0x00000022>;
        pinctrl-1 = <0x00000023>;
        max-frequency = <0x08f0d180>;
        bus-width = <0x00000004>;
        cap-sd-highspeed;
        no-mmc;
        keep-power-in-suspend;
        sunxi-dly-52M-ddr4 = <0x00000001 0x00000000 0x00000000 0x00000000 0x00000002>;
        sunxi-dly-104M = <0x00000001 0x00000000 0x00000000 0x00000000 0x00000001>;
        sunxi-dly-208M = <0x00000001 0x00000000 0x00000000 0x00000000 0x00000001>;
        status = "okay";
        no-sd;
        cap-sdio-irq;
        ignore-pm-notify;
        ctl-spec-caps = <0x00000008>;
};

修改sdc的最大支持频率

25M
fdt set /soc/sdmmc@04021000 max-frequency <0x017d7840>
50M
fdt set /soc/sdmmc@04021000 max-frequency <0x02faf080>
100M
fdt set /soc/sdmmc@04021000 max-frequency <0x05f5e100>
120M
fdt set /soc/sdmmc@04021000 max-frequency <0x07270e00>
150M
fdt set /soc/sdmmc@04021000 max-frequency <0x08f0d180>

修改相位

fdt set /soc/sdmmc@04021000 sunxi-dly-208M <0x00000001 0x00000000 0x00000000 0x00000000 0x00000000 0x00000001>

2.修改以太网的属性

打印当前以太网的配置

=> fdt print /soc/eth@4500000
eth@4500000 {
        compatible = "allwinner,sunxi-gmac";
        reg = <0x00000000 0x04500000 0x00000000 0x00010000 0x00000000 0x03000030 0x00000000 0x00000004>;
        interrupts = <0x00000000 0x0000002e 0x00000004>;
        interrupt-names = "gmacirq";
        clocks = <0x00000002 0x00000050 0x00000002 0x0000004f>;
        clock-names = "gmac", "ephy";
        resets = <0x00000002 0x00000020>;
        device_type = "gmac0";
        gmac-power0;
        gmac-power1;
        gmac-power2;
        status = "okay";
        phy-mode = "rgmii";
        use_ephy25m = <0x00000001>;
        pinctrl-0 = <0x00000019>;
        pinctrl-1 = <0x0000001a>;
        pinctrl-names = "default", "sleep";
        tx-delay = <0x00000003>;
        rx-delay = <0x00000005>;
};

修改delay 参数

fdt set /soc/eth@4500000 rx-delay  <0x0000000a>

注：这里只是简单介绍uboot的命令，具体设备属性的解释就不展开说明了。

解决办法

uboot常用命令
fdt

=> fdt -h
fdt - flattened device tree utility commands

Usage:
fdt addr [-c]  <addr> [<length>]   - Set the [control] fdt location to <addr>
fdt apply <addr>                    - Apply overlay to the DT
fdt boardsetup                      - Do board-specific set up
fdt move   <fdt> <newaddr> <length> - Copy the fdt to <addr> and make it active
fdt resize [<extrasize>]            - Resize fdt to size + padding to 4k addr + some optional <extrasize> if needed
fdt print  <path> [<prop>]          - Recursive print starting at <path>
fdt list   <path> [<prop>]          - Print one level starting at <path>
fdt get value <var> <path> <prop>   - Get <property> and store in <var>
fdt get name <var> <path> <index>   - Get name of node <index> and store in <var>
fdt get addr <var> <path> <prop>    - Get start address of <property> and store in <var>
fdt get size <var> <path> [<prop>]  - Get size of [<property>] or num nodes and store in <var>
fdt set    <path> <prop> [<val>]    - Set <property> [to <val>]
fdt mknode <path> <node>            - Create a new node after <path>
fdt rm     <path> [<prop>]          - Delete the node or <property>
fdt header                          - Display header info
fdt bootcpu <id>                    - Set boot cpuid
fdt memory <addr> <size>            - Add/Update memory node
fdt rsvmem print                    - Show current mem reserves
fdt rsvmem add <addr> <size>        - Add a mem reserve
fdt rsvmem delete <index>           - Delete a mem reserves
fdt chosen [<start> <end>]          - Add/update the /chosen branch in the tree
                                      <start>/<end> - initrd start/end addr

printenv:打印环境变量
setenv:设置环境变量
saveenv:保存设置的环境变量
md:显示内存区的内容
mm:修改内存
cmp:比较两块内存