Correct usage of usbmass to avoid MS corruption

ahman · Post by **ahman** » Wed Sep 12, 2007 3:56 pm

I noticed that some homebrews enable the use of usb mass storage, but incorrect usage will result in memory stick corruption.

Once a particular homebrew turned on usbmass and allow the user to use a PC to copy some files to the MS. Upon completion, the homebrew turned off usbmass. At this moment, the memory stick driver cache (consists of FAT table, etc) on the PSP is out of date and if the homebrew modify files on the MS, the memory stick will be corrupted. To avoid corruption, you'll need to invalidate the MS driver cache after unmounting usbmass, like this.

Code: Select all

sceIoDevctl&#40;"fatms0&#58;", 0x0240D81E, NULL, 0, NULL, 0 &#41;;

The above call to sceIoDevCtl will invalidate the cache and that's also what XMB did when the usbmass is unmounted. This will also result in all open file describtors to be closed.

Hellcat · Post by **Hellcat** » Wed Sep 12, 2007 8:36 pm

Wow, good info!
I will put that into the program I am currently writing....

sceIoDevctl("flashfat0:", 0x0240D81E, NULL, 0, NULL, 0 );
would do the same for flash0:/, am I right?

e_boris · Post by **e_boris** » Wed Sep 12, 2007 10:37 pm

Thanks for the tip. How do you get the device names? is there any name lists? I mean for the “fatms0:”

ahman · Post by **ahman** » Thu Sep 13, 2007 1:57 pm

Hellcat wrote:Wow, good info!
I will put that into the program I am currently writing....

sceIoDevctl("flashfat0:", 0x0240D81E, NULL, 0, NULL, 0 );
would do the same for flash0:/, am I right?

I doubt this command code will work on the flash. However, I haven't tried it myself.

e_boris wrote:Thanks for the tip. How do you get the device names? is there any name lists? I mean for the “fatms0:”

Actually, the "fatms0:" is a well known device name for the memory stick. If you try to disassemble some of the firmware PRXes, you'll find many different device names. I believe someone has also posted a device name list in this forum. You may wanna search for it.

weltall · Post by **weltall** » Fri Sep 14, 2007 3:40 pm

thanks for the tip ahman :)

kururin · Post by **kururin** » Fri Sep 14, 2007 8:31 pm

Hellcat wrote:Wow, good info!
I will put that into the program I am currently writing....

sceIoDevctl("flashfat0:", 0x0240D81E, NULL, 0, NULL, 0 );
would do the same for flash0:/, am I right?

the devctl codes are specific for each device. The one to flush flashfats is 0x00005802.

Torch · Post by **Torch** » Sun Jun 22, 2008 8:28 pm

Does anyone have more information about devctl commands for the flash. Such as free space, etc?