i've inserted my u3 usbstick and opened up my 1gb of memory/computer ram and searched for "removable" and have found a couple results that look like the removable device bit.
how i would change that idk.
i want to find some way of editing the firmware and changing that RMB bit from true to false.
i hope that possible.
July 6th, 2006, 01:00 AM
i tried changing the media descriptor in the boot sector of the usb stick from f8 (hard disk/fixed disk) but i don't know what to change it to. i don't know what hex value would represent a cdrom.
July 6th, 2006, 03:16 PM
Now that sounds interesting. It might translate into breaking the boot sector down into individual bits- some may be boolean flags... f8 would be 1111 1000 in binary, and if I recall correctly (if you're looking at the right thing), the removable media bit needs to be set from 1 to 0 (I'd have to review the posting for the exact position and value). Say for example it was bit 2 of the f8 code... if f8 is 1111 1000, and we needed to change bit 2 (assuming we're talking from R to L), that would change it to 1111 1010, or fa, so fa would become the new boot sector media descriptor...
Now how exactly ARE you managing to see and edit the boot sector of the USB stick??? That is a part of the puzzle I haven't come across yet...
July 6th, 2006, 04:13 PM
i downloaded a hex editor and loaded the RAM/memory and looked at it after plugging in the usb stick hoping to see and be able to grep for the removable media bit.
a couple results did come up for "DEVICE REMOVABLE" and another one i can't recall (i'll do it again and post it) that looked like what we're looking for.
a co-worker said try getting the firmware of the usbkey and going from there.
i was able to open the e:\ (usb key drive) in the hex editor and i was lookin at the boot sector.
CD's don't seem to have the same thing though, there is no boot sector i was able to look at.
i was going to copy the media descriptor from the cd-rom and change the usb-key's to it.
July 6th, 2006, 04:22 PM
Originally posted here by deftones12 i was able to open the e:\ (usb key drive) in the hex editor and i was lookin at the boot sector.
That's what I'm referring to. My hex editor will open any file I see in the directory under my usb drive- but I don't see any firmware files to edit/open.... just the files I've put in there myself. What am I mising?
July 6th, 2006, 04:36 PM
i used winhex, i've used it in the past and remember grepping and searching for passwords in memory.
yahoo messenger used to store passwords in plain text in memory and i was playing around with it.
July 7th, 2006, 05:36 AM
Actually I'm using Hexplorer, and I found I can examine the disk directly by sector (in NT/2000/XP). I was on a ME box before, it didn't have that option there. I've been able to view the disk sectors directly, have found what I think is a boot sector... I'm looking into info to translate what I'm seeing as best as I can... will advise.
July 7th, 2006, 04:07 PM
the media descriptor in the boot sector doesn't change anything sadly :(
July 8th, 2006, 05:43 PM
Still playing... So far, the only interesting change I can make (that does anything noticable) is that I have changed the name of the drive (one of them, anyway). So now when I insert it instead of saying TravelDrive, it says XanaDrive. Lame, I know, but at least I could change SOMETHING! :)
I'm pretty sure the answer exists somewhere within the code I can see at the very beginning of sector 0 on my drives... when I figure that bunch of code out, I should be able to make the drive do pretty much whatever I want.
Big IF though...
More as I find it.
August 24th, 2006, 03:25 AM
I've been trying to accomplish the same goal, and have come to the same brick wall. Have you had any developments lately? Some of the tips you give here are great, thanks.
I also pursued making a jump drive bootable, thinking that would get me closer. It worked, but still no autorun capabilities. Here are the two utilities I found to do it (if you don't already have them). This is the one made by HP (follow link), and the other is a Lexar utility (file attached), but it is my understanding that they will work on any drive.
What is very interesting is that the Lexar utility has a "Flip Removable Bit" button. I know, seems like exactly what we are looking for, but I have not been able to get it to make the drive autorun when inserted. Maybe you will have better results. Let me know what you find out.