Boot2 3.2.4.7 downgrade

[glamdisju]

Hello people!

I have seen a lot of resources on how to launch different operating systems on an nspire CX (I'd like to get CAS functionality)*
I know my way around hardware and I already had a "bus pirate" that I'm using to connect to the TTL UART on my nspire CX.

I've followed several guides to downgrade boot2 but I'm not getting it. The steps are follow are these:

My nspire CX has the following versions:
boot1: 3.0.0.99
boot2: 3.2.4.7
OS Version: 3.6.0.546
Identifier: P-0911D

1.- I connect my bus pirate and set it to tranparent bridge
2.- I reset my calc with doc+enter+2+reset buttons and I can see on the hyperterminal that its waiting for a boot2 image
3.- I upload boot2 image version 3.1.0.16
4.- The calculator accepts the new image and reboots
5.- Upon rebooting I find that the boot2 version is still 3.2.4.7


Is there any way around this? its another downgrade protection?

* In case you are wondering I'm doing it for fun, I just like to get the most out of every device I own.

[critor]

Hi.

Great if you've already got all the required hardware


You just need to remove OS 3.6 before reflashing the Boot2 through the maintenance menu:
Because each time OS 3.6 starts, it updates the Boot2 to 3.2.4.7 if it detects an older version.

[glamdisju]

Works like a charm!!

If I get some spare time I'll try to make a video-tutorial for the procedure with a bus pirate.

Thanks a lot!

[critor]

Great you succeeded.

And I'm looking forward to your video tutorial, as it will be very useful.