IOT-GATE-iMX7 and SBC-IOT-iMX7: Linux: Manual Installation: Source: USB

Introduction

This article provides an introduction on how to install the Linux kernel and the example root filesystem image on the IOT-GATE-iMX7 Internet of Things Gateway or CompuLab SBC-IOT-iMX7 Internet of Things Single Board Computer eMMC internal storage device using USB storage device as the installation source.

Preparation steps

• Obtain a PC workstation with a USB port.
• For networked installation you need to install a TFTP server on the host PC. For Windows machines we recommend TFTPD32 included in the Linux package (link below) under the utilities subdirectory.
• Download the BSP binary package for IOT-GATE-iMX7 and SBC-IOT-iMX7 from CompuLab website. Use either IOT-GATE-iMX7 or SBC-IOT-iMX7 product web page for downloading. Unzip the package to a directory on your host workstation.
• All image files mentioned below can be found in the install subdirectory.
• Use the standard microUSB-to-USB cable to connect the host PC to the micro USB connector marked Console on IOT-GATE-iMX7 rear panel (connector P3 on SBC-IOT-iMX7).
• Make sure the new /dev/ttyUSBx device file is created by using the ls /dev/ttyUSB* command. x is the last number of the ttyUSB device.

Preparing installation media

• Obtain a USB storage device of 1GB or larger .
• Create a first partition on it. The partition can be formatted either ext2/3/4 or FAT file system.
• Copy kernel.img, ramdisk.dtb, ramdisk.img, rootfs.tar.bz2, imx7d-*.dtb and zImage from the unzipped Linux package to the root directory on the first partition of the USB storage.

Boot into the installation environment (ramdisk)

• Start terminal emulation software on your PC with the following serial port settings:

Baud Rate	Data Bits	Stop Bits	Parity	Flow Control
115200	8	1	none	none

• Plug the installation media (USB storage device) to a any USB port on the IOT-GATE-iMX7 front/rear panel (slots P10-P13 on the SBC-iMX7).
• Make sure no other removable media (e.g. additional USB storage, micro SD) is plugged.
• Turn on the device. Press a key to prevent a possible autoboot and get into the U-Boot command prompt.

If the boot settings of your device are different than the default, you may need to press and hold Ctrl-C while turning the device on, in order to get command prompt.

• Use the following U-Boot commands to boot the installation environment on the device:

setenv ramdisk_addr 0x82000000; setenv fdtaddr 0x83000000
setenv bootargs 'root=/dev/ram0 rw ramdisk_size=16384 console=ttymxc0,115200 vram=16M'
usb start
load usb 0 ${loadaddr} kernel.img && load usb 0 ${fdtaddr} ${fdtfile} && load usb 0 ${ramdisk_addr} ramdisk.img
bootz ${loadaddr} ${ramdisk_addr} ${fdtaddr}

Install Linux Images

The next step is installing the kernel and Debian Linux images.

Mount the USB Storage Device

Use the following command to mount the installation USB storage:

root@cl-ramdisk:~# mount /dev/sda1 /mnt/install

Install Images on eMMC

• Unmount all eMMC partitions:

root@cl-ramdisk:~# umount -l /dev/mmcblk2p*

• Clean up the on the eMMC flash:

root@cl-ramdisk:~# dd if=/dev/zero of=/dev/mmcblk2 bs=1M count=1
root@cl-ramdisk:~# hdparm -z /dev/mmcblk2

• Create two partitions for the Linux kernel (EXT2 100M) and root file system (EXT4 the rest of the disk) on the eMMC flash:

root@cl-ramdisk:~# echo -e "n\np\n1\n\n+100M\nn\np\n2\n\n\nw\neof\n" | fdisk /dev/mmcblk2

• Format the first partition with EXT2 file system:

root@cl-ramdisk:~# mkfs.ext2 -L boot /dev/mmcblk2p1

• Format the second partition with EXT4 file system:

root@cl-ramdisk:~# mkfs.ext4 -L rootfs /dev/mmcblk2p2

• Mount both partitions:

root@cl-ramdisk:~# mkdir -p /media/boot && mount /dev/mmcblk2p1 /media/boot
root@cl-ramdisk:~# mkdir -p /media/rootfs && mount /dev/mmcblk2p2 /media/rootfs

• Copy zImage and imx7d-*imx7.dtb to the first (EXT2) partition:

root@cl-ramdisk:~# cp /mnt/install/zImage /mnt/install/imx7d-*.dtb /media/boot && sync

• Extract the content of rootfs.tar.bz2 onto the second partition:

root@cl-ramdisk:~# tar --numeric-owner -xpf /mnt/install/rootfs.tar.bz2 -C /media/rootfs && sync

• Unmount both partitions:

root@cl-ramdisk:~# umount /dev/mmcblk2p1
root@cl-ramdisk:~# umount /dev/mmcblk2p2

After Installation

• Remove the USB storage and reboot the device
• Press a key to prevent a possible autoboot and get into the U-Boot command prompt.
• Use the following U-Boot commands to configure eMMC as the main storage for both Linux kernel and root filesystem images:

env default -a
setenv bootdelay 3
setenv kernel zImage
setenv loadaddr 0x80800000
setenv fdtfile imx7d-sbc-iot-imx7.dtb
setenv fdtaddr 0x83000000
setenv mmcroot "/dev/mmcblk2p2 rootwait rw"
setenv loadimage 'load mmc 1:1 ${loadaddr} ${kernel}'
setenv loadfdt 'load mmc 1:1 ${fdtaddr} ${fdtfile}'
setenv bootargs "console=ttymxc0,115200 root=${mmcroot}"
setenv bootcmd 'run loadimage; run loadfdt; bootz ${loadaddr} - ${fdtaddr}'

• To save this configuration:

saveenv

• To boot Linux type:

run bootcmd

See also

• IOT-GATE-iMX7 and SBC-IOT-iMX7: Linux: Manual Installation from micro SD
• IOT-GATE-iMX7 and SBC-IOT-iMX7: Linux: Manual Installation from Network