Development Kits come with a microSD card that holds the display module’s operating system. It is highly recommended development is done on the SD card file system, because if something goes wrong it is easier to rewrite the SD card than to re-flash the NAND memory. The NAND image should be left alone until a production candidate is ready to be tested.
Using a Jumper to Select Boot Media
Turn the display module over and orient it so that the RS232 port is facing away from you, then look for the jumper labeled JP2 (located below the RS232 port). The two prongs on the left side of JP2 are the jumper leads which determine whether the module boots off of an SD card or NAND memory.
If no jumper is installed, the display module will boot from the SD card. If a jumper is installed, the display module will boot from onboard NAND (chip) memory.
It is highly recommended you boot from the SD card during development.
Writing a New SD Card In Windows
The process of writing images to a SD card on a Windows PC requires the use of a free utility such as Win32 Disk Imager.
Writing a New SD Card in Linux
On Linux, use the
'dd'. command to rewrite the SD card.
'dd' is easy to use, but if used incorrectly your PC’s hard drive may be rewritten. It is prudent to backup regularly. Find more details on the
'dd' man page here.
First, locate the path to the microSD card:
Look at the output and unmount anything mounted to /media. Note the command name is
'umount' not ‘unmount’.
$ umount /dev/sdb1
Also, make note of the location of Reach provided Linux .img file. For instance, it may be ~/Downloads/Reach-G2.img. Next use ‘dd’. if= stands for input file, and of= stands for output file.
$ sudo dd if=~/Downloads/Reach-G2.img of=/dev/sdb bs=4096
Press Return, enter your password, and
'dd' will copy the Reach image file to the SD card.