In the fw 200,002 was added the option "Updated via the HTTP server"
Debug Settings -> Update Server URL
This makes it easier management of the fw from our pc.
It is not necessary to follow the exact steps with directories, also know if the official way, but you can find this and finally it works.
-Update Server URL
http://192.168.0.X/ps3-updatelist.txt (192.168.0.x -> The IP of our pc)
In doing so the option is available: Update via Internet-> System Update
We must install a web server, Apache or another, in this case was Apache, install normally.
We look for the folder / htdocs (Program Files / Apache / htdocs) where we can create other folders to hold multiple fw or just put it in the root.
/ 220/PS3UPDAT.PUP -> fw 2.20 debug
/ 242/PS3UPDAT.PUP -> fw 2.42 debug
/ 315/PS3UPDAT.PUP -> fw 3.15 debug
In the root, / httdocs, copy the following files: ps3-updatelist.txt, it is important Dest = XX is the number 82 would be the flag that corresponds to the ps3_test, (81-reference tool, 82 - debugging station, 83 "JAP, etc. ..)
Dest = 82; ImageVersion = 0000a20e; SystemSoftwareVersion = 2.5200; CDN = http://192.168.0.5/update/ps3/252/PS3UPDAT.PUP; CDN_Timeout = 30;
This would be to install the version 2.52.
For version 3.15 would be the next, and so for each version you just have to change the number.
Dest = 82; ImageVersion = 0000a20e; SystemSoftwareVersion = 3.1500; CDN = http://192.168.0.5/update/ps3/252/PS3UPDAT.PUP; CDN_Timeout = 30;
And this would be the method, for up to download the version,you can have all the versions hosted on your pc.