UCM-iMX7: Linux: Manual Installation: Source: USB
Contents
Introduction
This article provides an introduction on how to install the Linux kernel and the example root filesystem image on the CompuLab UCM-iMX7 System-on-Module / Computer-on-Module 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 for UCM-iMX7 (link below).
- Download the Linux package for UCM-iMX7 from CompuLab website. 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 P7 on SBC-UCM-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.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 any USB port on the SBC-UCM-iMX7. Following USB ports can be used:
- Dual USB host port (P5)
- the USB OTG port (P3) with an appropriate adapter
- Make sure no other removable media (e.g. micro SD card or USB storage) 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:
UCM-iMX7 # env default -a UCM-iMX7 # setenv fdt_file sbc-ucm-imx7.dtb UCM-iMX7 # setenv ramdisk_addr 0x82000000 UCM-iMX7 # setenv bootargs 'root=/dev/ram0 rw ramdisk_size=16384 console=ttymxc0,115200 vram=16M' UCM-iMX7 # usb start UCM-iMX7 # load usb 0 ${loadaddr} kernel.img && load usb 0 ${fdt_addr} ${fdt_file} && load usb 0 ${ramdisk_addr} ramdisk.img UCM-iMX7 # bootz ${loadaddr} ${ramdisk_addr} ${fdt_addr}
Install Linux Images
The next step is installing the kernel and Debian Linux images.
Mount the USB Storage Device
- The source SD card is mounted automatically under /media/mmcblk0p1/.
- If for some reason the micro SD card hasn't been mounted automatically, use the following mount command:
root@cl-ramdisk:~# mkdir -p /media/mmcblk0p1 && mount /dev/mmcblk0p1 /media/mmcblk0p1
- Create a symbolic link to the source media:
root@cl-ramdisk:~# ln -s /media/sda1 /media/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/rootfs && mount /dev/mmcblk2p2 /media/rootfs root@cl-ramdisk:~# mkdir -p /media/rootfs/boot && mount /dev/mmcblk2p1 /media/rootfs/boot
- Extract the content of rootfs.tar.bz2:
root@cl-ramdisk:~# tar --numeric-owner -xpf /media/install/rootfs.tar.bz2 -C /media/rootfs && sync
- Copy zImage and imx7d-*imx7.dtb to the first (EXT2) partition:
root@cl-ramdisk:~# cp /media/install/zImage /media/install/imx7d-*.dtb /media/rootfs/boot && 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.
- The default U-Boot environment configuration falls back to boot from the internal storage eMMC if no proper images are found on a micro SD card.
- Alternatively, you can 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-ucm-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:
boot