Rockbox Development > New Ports

Creative Zen Vision:M

<< < (63/136) > >>

mcuelenaere:

--- Quote from: saratoga on July 23, 2007, 10:42:59 AM ---
--- Quote from: Transience on July 23, 2007, 01:05:15 AM ---Assuming the vision W and M are the same in terms of firmware upgrades, it seems that any checksumming done by the player is done using code stored on the player's ROM, as the HDD can be changed out on the vision W without any problems. http://onemansblog.com/2007/07/20/tutorial-how-to-upgrade-the-creative-zen-vision-w-hard-drive/

--- End quote ---
While I agree that the checksum must be calculated by the firmware in ROM (since doing it from the disk would make absolutely no sense at all), theres nothing specifically in that link to suggest its the case.

--- End quote ---
Yes there is: as the firmware has to be installed on the new HDD, the ZVM must upgrade its firmware and because the HDD is empty, the checksum can't be on it.

Anyway, I was thinking last night: there are several F* (FBOOT, FRESC) blocks and several H* (Hjukebox.grs, Hjukebox2.jrs, ...) blocks; if the F refers to flash and the H to HDD, it would mean everytime an upgrade is performed the boot code is flashed.

To prove my theory: if you look at the rescue menu, you'll see a version number. If you upgrade your firmware, this number changes. But if your HDD becomes corrupt or your ZVM won't boot anymore (you come automatically in Rescue mode), this number is the same (so it doesn't depend on a file on HDD).

So in short, a HDD dump wouldn't give us any real useful information, because (boot) code is stored in ROM/flash.

Also, there are 2 other strange blocks in nk.bin (EXT0 and an encrypted one), maybe one of them could contain DSP code and/or are written to a specific place (as none of them has an H or F in front of their name); but this has nothing to do with the above.

jermey:
i tell you something guys: put your zen nearby your ears and then swith it on and try somehow watch lcd and you will see that boot sector is on flash and firmware is on hdd

Transience:
after some searching, i found that the firmware isn't in the first 20-80mb of the HDD. On mine, 010 Editor shows that the firmware images, at least, are located around 2302:2F50h. i was able to modify one of the images on the disk, powercycle the player, and the modification was still there when i opened the drive again in 010. the image i changed was a green check mark, but i'm not sure where that image is used :(. If anyone knows, please let me know.

Mardoxx:
there's a checkmark when you change password protected content password
when you use the Custom EQ
ummm I've seen one somewhere before

I'll have a look :)

Transience:
back to the problem of the checksum, if the bootloader is checksumming the firmware, creative almost certainly used an existing function, rather than code their own. It seems that they may have coded the bootloader to skip parts of the firmware during the checksum, to save time. since the bootloader would have to be able to check future (not yet coded) firmware updates, it probably skips parts based on the block structure of the firmware (that would be the easiest way, anyway). so perhaps the bootloader is only checksumming certain blocks of the firmware, and skipping others?

Navigation

[0] Message Index

[#] Next page

[*] Previous page