[问答]

怎样通过uboot去修改sdc的频率以及以太网的delay参数呢

问答对人有帮助，内容完整，我也想知道答案 0 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。 => 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> ：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。 0
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答案对人有帮助，有参考价值 0 解决办法 uboot常用命令 fdt => fdt -h fdt - flattened device tree utility commands Usage: fdt addr [-c] [] - Set the [control] fdt location to fdt apply - Apply overlay to the DT fdt boardsetup - Do board-specific set up fdt move - Copy the fdt to and make it active fdt resize [] - Resize fdt to size + padding to 4k addr + some optional if needed fdt print [] - Recursive print starting at fdt list [] - Print one level starting at fdt get value - Get and store in fdt get name - Get name of node and store in fdt get addr - Get start address of and store in fdt get size [] - Get size of [] or num nodes and store in fdt set [] - Set [to ] fdt mknode - Create a new node after fdt rm [] - Delete the node or fdt header - Display header info fdt bootcpu - Set boot cpuid fdt memory - Add/Update memory node fdt rsvmem print - Show current mem reserves fdt rsvmem add - Add a mem reserve fdt rsvmem delete - Delete a mem reserves fdt chosen [ ] - Add/update the /chosen branch in the tree / - 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

2021-12-29 11:10:33 评论举报李代三