UBOOT环境配置及系统烧写
uboot默认参数信息
2025-08-06
95
0
输出信息
CPU: Freescale i.MX6ULL rev1.1 792 MHz (running at 396 MHz)
CPU: Industrial temperature grade (-40C to 105C) at 47C
Reset cause: POR
Board: I.MX6U ALPHA|MINI
I2C: ready
DRAM: 512 MiB
MMC: FSL_SDHC: 0, FSL_SDHC: 1
In: serial
Out: serial
Err: serial
switch to partitions #0, OK
mmc1(part 0) is current device
Net: FEC1
Error: FEC1 address 11:22:33:44:55:99 illegal value
配置信息
=> printenv
baudrate=115200
board_name=EVK
board_rev=14X14
boot_fdt=try #yes：必须成功加载设备树才能启动，no：不使用设备树启动，try：尝试加载设备树，如果失败则不使用设备树继续启动
bootargs=console=ttymxc0,115200 root=/dev/nfs \
nfsroot=192.168.0.3:/home/zzmt/Desktop/nfs/rootfs,proto=tcp rw \
ip=192.168.0.66:192.168.0.3:192.168.0.1:255.255.255.0::eth0:off
bootcmd=tftp 80800000 zImage; tftp 83000000 imx6ull-14x14-evk-emmc.dtb;bootz 80800000 - 83000000
bootcmd_mfg=run mfgtool_args;bootz ${loadaddr} ${initrd_addr} ${fdt_addr};
bootdelay=3
bootscript=echo Running bootscript from mmc ...; source
console=ttymxc0
ethact=FEC1 #表示Fast Ethernet Controller，i.MX6ULL的以太网控制器
ethaddr=11:22:33:44:55:99
ethprime=FEC
fdt_addr=0x83000000
fdt_file=imx6ull-14x14-emmc-4.3-480x272-c.dtb
fdt_high=0xffffffff #限制设备树和initrd在内存中的加载位置，xffffffff 表示不限制
findfdt=if test $fdt_file = undefined; then if test $board_name = EVK && test $board_rev = 9X9; then setenv fdt_file imx6ull-9x9-evk.dtb; fi; if test $board_name = EVK && test $board_rev = 14X14; then setenv fdt_file imx6ull-14x14-evk.dtb; fi; if test $fdt_file = undefined; then echo WARNING: Could not determine dtb to use; fi; fi;
gatewayip=192.168.0.1
image=zImage #内核镜像文件名
initrd_addr=0x83800000
initrd_high=0xffffffff #xffffffff 表示不限制
ip_dyn=yes #yes：使用DHCP获取IP,no：使用静态IP
ipaddr=192.168.0.66
loadaddr=0x80800000
loadbootscript=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};FAT文件系统加载boot.scr
loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file} #从MMC加载设备树文件
loadimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${image} #从MMC加载内核镜像。
logo_file=alientek.bmp ##启动logo图片文件名
mfgtool_args=setenv bootargs console=${console},${baudrate} rdinit=/linuxrc g_mass_storage.stall=0 g_mass_storage.removable=1 g_mass_storage.file=/fat g_mass_storage.ro=1 g_mass_storage.idVendor=0x066F g_mass_storage.idProduct=0x37FF g_mass_storage.iSerialNumber="" clk_ignore_unused
mmcargs=setenv bootargs console=${console},${baudrate} root=${mmcroot}
mmcautodetect=yes
mmcboot=echo Booting from mmc ...; run mmcargs; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
mmcdev=1 #1 通常表示eMMC，0 通常表示SD卡
mmcpart=1 #表示第一个分区
mmcroot=/dev/mmcblk1p2 rootwait rw
netargs=setenv bootargs console=${console},${baudrate} root=/dev/nfs ip=dhcp nfsroot=${serverip}:${nfsroot},v3,tcp
netboot=echo Booting from net ...; run netargs; if test ${ip_dyn} = yes; then setenv get_cmd dhcp; else setenv get_cmd tftp; fi; ${get_cmd} ${image}; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if ${get_cmd} ${fdt_addr} ${fdt_file}; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
netmask=255.255.255.0
panel=ATK-LCD-4.3-480x272 ##LCD面板型号，用于显示驱动配置
script=boot.scr
serverip=192.168.0.3
splashimage=0x88000000
splashpos=m,m #屏幕中央显示（middle）
stderr=serial
stdin=serial
stdout=serial
Environment size: 2772/8188 bytes
基本配置
baudrate=115200 # 串口波特率
board_name=EVK # 板卡名称
board_rev=14X14 # 板卡版本
bootdelay=3 # 启动延时3秒
console=ttymxc0 # 控制台设备
网络配置
baudrate=115200 # 串口波特率
board_name=EVK # 板卡名称
board_rev=14X14 # 板卡版本
bootdelay=3 # 启动延时3秒
console=ttymxc0 # 控制台设备
内存地址定义
loadaddr=0x80800000 # 内核加载地址
fdt_addr=0x83000000 # 设备树加载地址
initrd_addr=0x83800000 # 初始RAM磁盘加载地址
splashimage=0x88000000 # 启动画面地址
默认启动命令bootcmd
bootcmd 保存着 uboot 默认命令， uboot 倒计时结束以后就会执行 bootcmd 中的命令.
bootcmd=tftp 80800000 zImage; tftp 83000000 imx6ull-14x14-evk-emmc.dtb; bootz 80800000 - 83000000
- 通过 TFTP 下载内核 zImage 到 0x80800000
- 通过 TFTP 下载设备树 imx6ull-14x14-evk-emmc.dtb 到 0x83000000
- 使用 bootz 命令启动内核
mmc dev 1 //切换到 EMMC
fatload mmc 1:1 0x80800000 zImage //读取 zImage 到 0x80800000 处
fatload mmc 1:1 0x83000000 imx6ull-14x14-evk.dtb //读取设备树到 0x83000000 处
bootz 0x80800000 - 0x83000000 //启动 Linux
信息
=> ls mmc 1:1
39459 imx6ull-14x14-emmc-10.1-1280x800-c.dtb
39459 imx6ull-14x14-emmc-4.3-480x272-c.dtb
39459 imx6ull-14x14-emmc-4.3-800x480-c.dtb
39459 imx6ull-14x14-emmc-7-1024x600-c.dtb
39459 imx6ull-14x14-emmc-7-800x480-c.dtb
40295 imx6ull-14x14-emmc-hdmi.dtb
40203 imx6ull-14x14-emmc-vga.dtb
6785480 zimage
网络启动配置
netboot=echo Booting from net ...; run netargs; if test ${ip_dyn} = yes; then setenv get_cmd dhcp; else setenv get_cmd tftp; fi; ${get_cmd} ${image}; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if ${get_cmd} ${fdt_addr} ${fdt_file}; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
格式化后
echo Booting from net ...;
run netargs;
if test ${ip_dyn} = yes; then //dhcp
setenv get_cmd dhcp;
else
setenv get_cmd tftp;
fi
${get_cmd} ${image};
if test ${boot_fdt} = yes || test ${boot_fdt} = try; then
if ${get_cmd} ${fdt_addr} ${fdt_file}; then
bootz ${loadaddr} - ${fdt_addr};
else
if test ${boot_fdt} = try; then
bootz;
else
echo WARN: Cannot load the DT;
fi
fi
else
bootz;
fi
EMMC启动配置
mmcboot=echo Booting from mmc ...; run mmcargs; if test ${boot_fdt} = yes || test ${boot_fdt} = try; then if run loadfdt; then bootz ${loadaddr} - ${fdt_addr}; else if test ${boot_fdt} = try; then bootz; else echo WARN: Cannot load the DT; fi; fi; else bootz; fi;
格式化后
mmcboot=echo Booting from mmc ...;
run mmcargs;
if test ${boot_fdt} = yes || test ${boot_fdt} = try; then
if run loadfdt; then
bootz ${loadaddr} - ${fdt_addr};
else
if test ${boot_fdt} = try; then
bootz;
else
echo WARN: Cannot load the DT;
fi
fi
else
bootz;
fi
设备树选择逻辑
findfdt=if test $fdt_file = undefined; then
if test $board_name = EVK && test $board_rev = 9X9; then
setenv fdt_file imx6ull-9x9-evk.dtb;
fi;
if test $board_name = EVK && test $board_rev = 14X14; then
setenv fdt_file imx6ull-14x14-evk.dtb;
fi;
if test $fdt_file = undefined; then
echo WARNING: Could not determine dtb to use;
fi;
fi;
网络文件系统启动参数
bootargs=console=ttymxc0,115200 root=/dev/nfs \
nfsroot=192.168.0.3:/home/zzmt/Desktop/nfs/rootfs,proto=tcp rw \
ip=192.168.0.66:192.168.0.3:192.168.0.1:255.255.255.0::eth0:off
- root=/dev/nfs：使用NFS作为根文件系统
- nfsroot=192.168.0.3:/home/zzmt/Desktop/nfs/rootfs：NFS服务器路径
- ip=192.168.0.66:192.168.0.3:192.168.0.1：静态IP配置
bootargs 环境变量是由 mmcargs 设置的,默认mmcargs内容如下：
mmcargs=setenv bootargs console=${console},${baudrate} root=${mmcroot}
展开后
mmcargs=setenv bootargs console= ttymxc0, 115200 root=/dev/mmcblk1p2 rootwait rw
- console 用来设置 linux 终端
- root 用来设置根文件系统的位置
- rootwait 表示等待 mmc 设备初始化完成以后再挂载
- rw 表示根文件系统是可以读写的，不加rw 的话可能无法在根文件系统中进行写操作，只能进行读操作
=> ls mmc 1:2
<DIR> 4096 .
<DIR> 4096 ..
<DIR> 16384 lost+found
<DIR> 4096 sys
<DIR> 4096 boot
<DIR> 4096 mnt
<DIR> 4096 lib
<DIR> 4096 run
<DIR> 4096 proc
<DIR> 4096 usr
<DIR> 4096 home
<DIR> 4096 sbin
<DIR> 4096 dev
<DIR> 4096 opt
<DIR> 4096 etc
<DIR> 4096 bin
<DIR> 4096 var
<DIR> 4096 media
<SYM> 8 tmp
<DIR> 4096 .cache
<DIR> 4096 .config
EMMC启动参数
mmcroot=/dev/mmcblk1p2 rootwait rw
- 从EMMC的第2个分区启动
制造工具相关
bootcmd_mfg=run mfgtool_args;bootz ${loadaddr} ${initrd_addr} ${fdt_addr};
解析后
mfgtool_args=setenv bootargs console=${console},${baudrate} rdinit=/linuxrc g_mass_storage.stall=0 g_mass_storage.removable=1 g_mass_storage.file=/fat g_mass_storage.ro=1 g_mass_storage.idVendor=0x066F g_mass_storage.idProduct=0x37FF g_mass_storage.iSerialNumber="" clk_ignore_unused
- g_mass_storage.：Linux USB Gadget驱动参数，将设备模拟为U盘
- rdinit=/linuxrc：指定初始进程
- clk_ignore_unused：忽略未使用的时钟，防止功耗管理关闭必要时钟
