Now that we've built a new root file system and established a serial connection with kermit it's time to reprogram our gumstix's flash memory.

The following instructions assume that you have completed the steps in Setting up a serial connection.

Reboot your gumstix, hit any key to stop the autoboot process and drop into U-Boot. At this point you should verify that your U-Boot version is 1.2.0. If it is not, then you will need to read the section on Updating U-Boot.

NOTE: At the moment gumstix-oe does not yet build U-Boot. If you need to update U-Boot you can find pre-built U-Boot binaries at:

http://www.gumstix.net/feeds/u-boot

First, we'll tell U-Boot to prepare to receive a file download at RAM location a2000000:

GUM> loadb a2000000

Now we'll break the serial connection and return to the kermit prompt by pressing Ctrl-backslash and then c. Set up the file transfer by typing:

C-Kermit> cd ~/gumstix/gumstix-oe/tmp/deploy/glibc/images/gumstix-custom-verdex/
C-Kermit> send gumstix-basic-image-gumstix-custom-verdex.jffs2 

Tip: Tab command completion is your friend. Kermit will help you type in those long path names.

After typing in the send command, you'll see a screen displaying the progress of the file upload process:

C-Kermit 8.0.211, 10 Apr 2004, localhost



Current Directory: /home/sakoman/gumstix/gumstix-oe/tmp/deploy/glibc/images/
Communication Device: /dev/ttyUSB0
Communication Speed: 115200
Parity: none
RTT/Timeout: 01 / 02
SENDING:  => GUMSTIX-BASIC-IMAGE-GUMSTIX-CUSTOM-VERDEX.JFFS2
File Type: BINARY
File Size: 7491192
Percent Done: 2   /
...10...20...30...40...50...60...70...80...90..100
Estimated Time Left: 00:13:32
Transfer Rate, CPS: 8963
Window Slots: 1 of 1
Packet Type: D
Packet Count: 68
Packet Length: 4096
Error Count: 0
Last Error:
Last Message:


X to cancel file, Z to cancel group,  to resend last packet,

E to send Error packet, ^C to quit immediately, ^L to refresh screen.

When this process completes your new filesystem has been loaded into gumstix RAM. The contents of Flash are still intact.

Now we'll leave kermit's command mode and reinstate our serial connection to the gumstix:

C-Kermit> connect

Getting the new filesystem copied into flash memory is a two-step process. First, the old filesystem must be erased; then, the new filesystem must be written from RAM to flash.

To erase the old filesystem, enter

GUM> protect on 1:0-1
GUM> erase all

The first line protects flash sectors 0 and 1, which contain the uboot bootloader. This line is very important! If you omit it, your Gumstix will be unusable and will have to be reflashed using a far more complicated process. The second line erases all of flash except the 2 sectors that we just protected.

Now, commit your new filesystem to flash:

GUM> cp.b a2000000 40000 ${filesize}

This copies your new filesystem into flash (at address 40000). ${filesize} is a reference to the variable filesize, which was set by your file transfer.

Now, we use a similar process to load the kernel:

GUM> loadb a2000000
C-Kermit> send uImage-2.6.21-r1-gumstix-custom-verdex.bin 
C-Kermit> connect
GUM> katinstall 100000
GUM> katload 100000
GUM> bootm