BH40N firmware and misadventures.

[ArsonOasis]

I recently came into possession of a small pile of Blu-Ray drives, 8 in total. One HL-DS BH30N and 7 HL-DS BH40Ns, 6 of which are dated Jan 2013 and one of which is dated Dec 2013.
I know the BH30N is basically useless because of how old it is, so I have ignored it for the time being.
All the BH40N drives are labeled as having firmware A102, although the drive dated Dec 2013 shows up in MakeMKV as having firmware 0.A102D and libredrive supported while the others do not. I have already given this drive away to a friend, but she was kind enough to dump the firmware for me when I thought to try flashing it to the others.
Tonight I started poking around with things, the A102D firmware appears to work on the January dated drives, they show up as libredrive compatible and can rip disks.
I also managed to brick one by ignoring the warning SDFtool has about the boot-loader flashing mode. This is what happens when I don't RTFM. I seem to have broken the boot-loader so bad that even having it plugged into the Dell 9020 I have been using for this keeps the machine from POSTing.

After this bit of fun I had a few questions for the more experienced folks here.

1. Where can I get the most "correct" firmware for a BH40N? The compatibility page lists A1B0 and GP01 but not A102, and I don't see either of these in the firmware packs linked in the tutorial pages.
2. Is there a way to "unbrick" the BH40N I messed up by flashing with the wrong flag? Not a big deal if not, it is one of six, I'd just rather not trash it over a recoverable mistake.
3. What exactly does the "de" flag in sdftool do? The help text "Sets DE byte in image" gives me some context that it is needed for certain firmwares, but I am not entirely sure what it does.

I am happy to provide firmware dumps or more details about these drives.

[Billycar11]

nah its dead no coming back if the pc cant turn on with it connected.
the risk to reward for flashing a BH40N is bad why flash it, it will never do UHD at most you dont have to worry about your aacs temporally being revoked until makemkv is updated this is 100% not worth it when an new aacs comes out makemkv is updated very quickly.
also your friend likely did not dump you the firmware if they used sdf tool it was only the calibration data duming fw can only be done by us with dos flash or the developer of makemkv can do it but it takes 45min+ with a remote session and this will only be done for new interesting fw to benefit UHD support and beyond not on some 10 year old drive that cant do UHD.

so really what made you flash these?
i hope it not because you mixed it up with a BU40N's capability's

[Billycar11]

i maybe wrong about the fw dump thing then older LG fw it could do a full dump but new stuff it cant and only does cal data
still this tool is made for mt1959 drives primarily but can also flash mt1939 dont know what yours are im guessing older than that so they may not use the same flashing procedure.
but yeah generally dont touch the fw unless you can make it do UHD or some other major feature you know it can achieve dont flash it to flash it or just to make it say libredrive enabled there's no benefit.
you got yourself some spare drive rubber bands and some other parts pcb with the controller is dead you can reuse most the other stuff if you wanted to for the other drives the magnetic disc holder is fun to use drives with the top off if those use that mechanism


stuff about dos flash here: https://www.youtube.com/watch?v=eXgybNfHhcg&t

[ArsonOasis]

Re-Writing the reply I posted last night as it was deleted as a duplicate post when I tried to edit a typo.

nah its dead no coming back if the pc cant turn on with it connected.

Not a big deal, the drives were free after all.

the risk to reward for flashing a BH40N is bad why flash it, it will never do UHD at most you dont have to worry about your aacs temporally being revoked until makemkv is updated this is 100% not worth it when an new aacs comes out makemkv is updated very quickly.
...
so really what made you flash these?
i hope it not because you mixed it up with a BU40N's capability's

I am certainly not confused about the model of drive I am working with. I know it is outdated, not recommended, and will not support UHD disks. This isn't an issue for me, I have a WH16NS60 for UHD stuff. This is more about having an opportunity to learn more about this topic by trying things, with so little of the inside details of these publicly documented this is a way to sate my curiosity about it.

also your friend likely did not dump you the firmware if they used sdf tool it was only the calibration data duming fw can only be done by us with dos flash or the developer of makemkv can do it but it takes 45min+ with a remote session and this will only be done for new interesting fw to benefit UHD support and beyond not on some 10 year old drive that cant do UHD.

It seems a little bit misleading the way sdftool is documented if it does not actually dump the whole firmware, although I understand the reasoning since most of the target userbase is using it for one specific purpose.
What tools can be used for whole firmware dumps? I am familiar with using firmware modification and flashing tools in FreeDOS for Motherboard BIOS, RAID cards, hard drives, etc. and most of those tools are quite application specific, so some guidance on where to look would be quite helpful.

I am certainly not looking for the developer or anyone else to do some miracle to make these old drives work with UHD disks, I really just want to use this as a way to get a better understanding of how the insides of these tools work.

[ArsonOasis]

i maybe wrong about the fw dump thing then older LG fw it could do a full dump but new stuff it cant and only does cal data
still this tool is made for mt1959 drives primarily but can also flash mt1939 dont know what yours are im guessing older than that so they may not use the same flashing procedure.
but yeah generally dont touch the fw unless you can make it do UHD or some other major feature you know it can achieve dont flash it to flash it or just to make it say libredrive enabled there's no benefit.

The BH40N uses the MT1939 platform/chipset, and libredrive is the main feature I was aiming to get. The 0.A102D firmware version sdftool dump that I got from the one slightly later model worked just fine to bring multiple drives which initially did not support libredrive into support.

stuff about dos flash here: https://www.youtube.com/watch?v=eXgybNfHhcg&t

Thanks for the info!
I was also looking at using https://github.com/devilsclaw/flasher as well, I don't mind using a Windows tool, I just don't keep any non-virtualized Windows machines at home normally so I usually look for Linux tools first.

[Billycar11]

i maybe wrong about the fw dump thing then older LG fw it could do a full dump but new stuff it cant and only does cal data
still this tool is made for mt1959 drives primarily but can also flash mt1939 dont know what yours are im guessing older than that so they may not use the same flashing procedure.
but yeah generally dont touch the fw unless you can make it do UHD or some other major feature you know it can achieve dont flash it to flash it or just to make it say libredrive enabled there's no benefit.

The BH40N uses the MT1939 platform/chipset, and libredrive is the main feature I was aiming to get. The 0.A102D firmware version sdftool dump that I got from the one slightly later model worked just fine to bring multiple drives which initially did not support libredrive into support.

stuff about dos flash here: https://www.youtube.com/watch?v=eXgybNfHhcg&t

Thanks for the info!
I was also looking at using https://github.com/devilsclaw/flasher as well, I don't mind using a Windows tool, I just don't keep any non-virtualized Windows machines at home normally so I usually look for Linux tools first.

Still my 1939 can't do UHD libredrive does basically nothing for them just leave them as is.
If the new fw is what you want just update through LGs site if it's the lastest it's way safer but generally updating is a no no as it removes features