code of blink led
werner at openmoko.org
Thu Jun 5 21:53:54 CEST 2008
> I write some code. but i don't know how to download it to GTA02
> and how to run it?
You can use u-boot from NOR for this:
- press and hold AUX, then press and hold POWER until the boot menu
comes up. Then release POWER and AUX.
The title of the boot menu should read
"*** BOOT MENU (NOR) ***"
- download your program into RAM (at address 0x32000000), with
dfu-util -a 0 -R -D led_on
- connect to the u-boot console over the serial interface or over USB
- copy your program from RAM to NAND:
nand erase u-boot
nand write.e 0x32000000 0 0x1000
Then reboot and see what happens ...
Right, nothing. This is where the fun of debugging begins ;-)
A few hints:
- you have the on/off logic inversed: 1 means "on", 0 means "off".
- your delay loop is slower than you may expect. Try changing it
After changing the delay loop, the LEDs should flash a few times,
then suddenly stop. Can you guess why ?
There is also a faster way for loading code than DFU: start OpenOCD,
then do this
> reset halt
> load_image /path/to/led_on 0
This will load your code into SteppingStone's BootSRAM (see below)
and execute it from there. Note that if you use this approach, the
program is lost after a reset.
> another question :
> where is the GTA02's LED? :-)
You mean physically ? There is a red LED behind the AUX button and
there are a blue and an orange LED behind the POWER button.
If you open the front cover of the Neo, you can see the red LED
behind AUX very clearly.
> what is the best TEXT_BASE value
0 is the right choice. See also figure 6-4 on page 6-9 of the
SC32442B54 manual. The "SteppingStone" boot loader (inside the CPU)
loads the first 4kB if NAND into this buffer.
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