It gives me a rough idea on how to go through from 5.4.0 to the current 6.2.3 in an upgrade path, but the more fundamental question I don't see answered, or maybe because terms are being thrown around imprecisely - what exactly is meant by upgrade path?
I have a single ASR 5525-X in single context transparent mode. Nothing on it, running ASA 9.9.2 and ASDM 22.214.171.124 because I am doing development work not production.
When I get a device out of the warehouse, and it is running 5.4.0 and I do not care about any settings on the device, is there a way to simply upgrade straight to the current version without all the stepping, or were there things done at the system level and not reproduced in later patches which are unskippable?
Is there an upgrade path for things where I do care about policies and setting, but then the upgrade path where I don't need to retain anything - in the name of expediency?
If I have to jump to 6.0.0 and then 6.0.1 then 6.1.0 to be able to get to 6.2.3 then, sure...but I'd like to know if I can make a volatile upgrade and set it up as new because after this configuration is set we'll have to do it on pallets of more devices and the "stepping" is tedious.
EDIT: It can be done directly. The FP module will come up on your management interface as a second IP, you have to use FTP, HTTP, or HTTPS to send the image (no SFTP, no SCP for some reason) and your mind is going to be much happier if you use:
debug module-boot 255
So that you can see what it's doing and not think it's just stuck. It will also help to get through the right sequence to set the desired image and boot it into recovery properly when it's in a weird state like recovery or unreachable from previous efforts and you need to reload it and swap the IMG out for a different one.
Once it gets to Executing S01 - you are in for a wait and it tells you this.