SAMSUNG YH-920

[dado84]

I own a 820 with janus bootloader, and finally this night I've been booting rockbox !!!

What is ment with janus bootloader?

Usually the 820 is shipped with 2.10 bootloader or similar;

after the "mtp" update using the "820firmwareupdate_mtp.exe" update file, the original bootloader is overwritten by the v5.00JN version and I haven't found no way to downgrade to the original one.
this update is useful since after that you can use the 820 as a MTP device loading music using a simple copy & paste!

unfortunately with that bootloader no one of the rockbox loader from samsung port was working.

is the same problem posted by the user shadoxx that have the same bootloader.
( http://forums.rockbox.org/index.php?topic=21794.0 )

The YH820 bootloader renamed to YH820_J.mi4 does not work?

Nope.
Unfortunately with all that bootloader the only thing that came out was :
"Connect to PC and repair firmware with recovery utility"

probably the mi4 code for the janus firmware is different from the normal one
the loader I used is 64kb while yh820/920 normal are 47/50 Kb around.

("janus" mean a DRM tech from microsoft , this is what i found reading around )

[pyro_maniac]

For the 920 there was a rollback tool for MTP update. Have you found one for the 820? On the global download center there seems to be none but even no MTP upgrade.

Nichlas seems to have the same problem like you with his 925.

[dado84]

nope, i've searched in every samsung download site but for the 820 there isn't a rollback utility, I've found only the one for the 925.

[pyro_maniac]

and where did you find the update?

and rockbox is running now with your h10 bootloader?

[dado84]

and where did you find the update?

and rockbox is running now with your h10 bootloader?

do you mean the Janus update for the 820 ?
you can download it from here: http://rapidshare.com/files/7999029/820firmwareupgrade_for_MTP.exe.html

but be aware that there is no rollback possibility !!!!!!


regarding rockbox; yes. I'm using daily build for the 820 (I trided the 920 one but doesn't start) and I'm using the h10 20gb firmware loader

[ThunderStorm]

I own a 820 with janus bootloader, and finally this night I've been booting rockbox !!!

to let it boot it I had to use the Iriver 20 Gb bootloader renamed as YH820_J.mi4
( http://download.rockbox.org/bootloader/iriver/H10_20GC.mi4 )

The YH820 bootloader renamed to YH820_J.mi4 does not work?

This does not work if the bootloader is Janus V5 JN

The booting is not successful.

[pyro_maniac]

@ThunderStorm: you missed this

regarding rockbox; yes. I'm using daily build for the 820 (I trided the 920 one but doesn't start) and I'm using the h10 20gb firmware loader

[ThunderStorm]

@ThunderStorm: you missed this

regarding rockbox; yes. I'm using daily build for the 820 (I trided the 920 one but doesn't start) and I'm using the h10 20gb firmware loader

I've put rockbox firmware into my YH-820, but it still won't work.
The system hangs at the splash.

So I'm afraid that Janus bootloader is incompatible with our rockbox firmware, but samsung does not provide any tools for writing bootloader area.

[Nichlas]

I can confirm that the H10 MTP bootloader does work for the Janus version of the samsung YH-925,booting rockbox.
I have also managed to exchange the hardrive for a 8 GB CF. Will post more in wiki in the future.
However when trying to boot OF i get a strange superimposed upside down message.

[lowlight]

I suspect that the Janus versions might require the Rockbox bootloader to be encoded using mi4v3 (like the H10 bootloader). I've made versions of the 820 and 925 bootloaders with this change for someone to verify.

http://drop.io/low_light/asset/fw-yh820-j-mi4
http://drop.io/low_light/asset/fw-yh925-j-mi4

You'll need to rename them appropriately.

[Nichlas]

Great job! The bootloader works for rockbox on janus yh-925.
Sadly not with OF. Say's invalid key, and cant load file.
But that's a problem for another day

Forgot to try the old OF without Janus.
However it dosent seem to work either.
A screen pops up and says:
"your device is being upgraded for subscription service. Pleas wait until the upgrade is completely finished"

[ThunderStorm]

I suspect that the Janus versions might require the Rockbox bootloader to be encoded using mi4v3 (like the H10 bootloader). I've made versions of the 820 and 925 bootloaders with this change for someone to verify.

http://drop.io/low_light/asset/fw-yh820-j-mi4
http://drop.io/low_light/asset/fw-yh925-j-mi4

You'll need to rename them appropriately.

Thanks for your encoded bootloader, it works.

But it says "can't load rockbox.mi4"

I've put rockbox files into correct folders.(/.rockbox)

[lowlight]

Thanks for your encoded bootloader, it works.

But it says "can't load rockbox.mi4"

I've put rockbox files into correct folders.(/.rockbox)

Did you catch the error after it says "Can't load rockbox.mi4"?

My svn tree was not clean when I made those bootloaders, but I don't think it should have messed anything up.

[ThunderStorm]

Thanks for your encoded bootloader, it works.

But it says "can't load rockbox.mi4"

I've put rockbox files into correct folders.(/.rockbox)

Did you catch the error after it says "Can't load rockbox.mi4"?

My svn tree was not clean when I made those bootloaders, but I don't think it should have messed anything up.

The error message after "Can't load rockbox.mi4" is
"File not found." But I've put rockbox files into my YH-820,into correct paths

[lowlight]

If it worked for Nichlas on his yh-925, I can't think of why it wouldn't work on an 820.

Are the Janus versions seen as a USB mass storage device or MTP (you use Windows media player)? It needs to be a mass storage device to save the folder to the right place.