fdt命令的使用

官方参考：https://www.denx.de/wiki/DULG/UBootCmdFDT

U_BOOT_CMD(
	fdt,	255,	0,	do_fdt,
	"flattened device tree utility commands",
	    "addr   <addr> [<length>]        - Set the fdt location to <addr>\n"
#ifdef CONFIG_OF_BOARD_SETUP
	"fdt boardsetup                      - Do board-specific set up\n"
#endif
	"fdt move   <fdt> <newaddr> <length> - Copy the fdt to <addr> and make it active\n"
	"fdt resize                          - Resize fdt to size + padding to 4k addr\n"
	"fdt print  <path> [<prop>]          - Recursive print starting at <path>\n"
	"fdt list   <path> [<prop>]          - Print one level starting at <path>\n"
	"fdt set    <path> <prop> [<val>]    - Set <property> [to <val>]\n"
	"fdt mknode <path> <node>            - Create a new node after <path>\n"
	"fdt rm     <path> [<prop>]          - Delete the node or <property>\n"
	"fdt header                          - Display header info\n"
	"fdt bootcpu <id>                    - Set boot cpuid\n"
	"fdt memory <addr> <size>            - Add/Update memory node\n"
	"fdt rsvmem print                    - Show current mem reserves\n"
	"fdt rsvmem add <addr> <size>        - Add a mem reserve\n"
	"fdt rsvmem delete <index>           - Delete a mem reserves\n"
	"fdt chosen [<start> <end>]          - Add/update the /chosen branch in the tree\n"
	"                                        <start>/<end> - initrd start/end addr\n"
	"NOTE: Dereference aliases by omiting the leading '/', "
		"e.g. fdt print ethernet0."
);

示例：

1. 首先将dtb文件上传

tftpboot 0x84000000 board.dtb

2.设置fdt的地址

fdt addr 0x84000000

3. 打印header信息

fdt header

4.打印/

fdt print /