Ext ROM install has left me with bad blocks!!!

[silent_killa]

Hi all.
I've gotten into the habit to use mtty everytime i flash a rom/radio to check for bad blocks.
I decided to give WM Black Editon a go from the LVSW edition. All was fine untill I decided to use the ext rom for a couple of programs. I installed spb Weather which went perfect and then I installed Skype. The Skype install hanged for about 10min so i had no choice but to soft reset.
After checking my device with mtty it now reports bad blocks. Phone works fine with no problems but my ext rom is now pretty much useless.
Just a warning to those who might give it a try.
Please let me know if there are any breakthroughs as to repair these bad blocks, surely it would just involve something like a low-level format.....??

S.K.

[Olipro]

what's the address of the bad blocks?

[silent_killa]

Readout from mtty:

Block 0x0(0) is Reversed block
Block 0x1(1) is Reversed block
Block 0x2(2) is Reversed block
Block 0x3(3) is Reversed block
Block 0x4(4) is Reversed block
Block 0x5(5) is Reversed block
Block 0x6(6) is Reversed block
Block 0x7(7) is Reversed block
Block 0x8(8) is Reversed block
Block 0x9(9) is Reversed block
Block 0xA(10) is Reversed block
Block 0xB(11) is Reversed block
Block 0xC(12) is Reversed block
Block 0x3A8(936) is BAD block !!!
Block 0x3A9(937) is BAD block !!!
Block 0x3AA(938) is BAD block !!!
Block 0x3F8(1016) is Reversed block

Partition[0], type=0x20, start=0x2, total=0x18FE
Partition[1], type=0x23, start=0x1900, total=0x1800
Partition[2], type=0x25, start=0x3100, total=0x1E500
Partition[3], type=0x4, start=0x21600, total=0x19200

CE Total Length(with sector info) = 0x43CB000
CE CheckSum Length(without sector info) = 0x42C0000

[Olipro]

yeah... they're manufacturer-marked BAD NAND blocks; you haven't actually lost any space, just ignore them

[silent_killa]

Excellent.
Just so annoying though that one takes so much care in flashing like disabling antivirus, closing down uneccessary processes, fresh reboot, etc etc and installing an app does me for crying out loud.
Ah well, phone is still good so i cant complain.

Would you please explain a little deeper as to Manufacter's marked blocks??
Just for interests sake.
Thanks for the insight

S.K.

[jasjamming]

Excellent.
Just so annoying though that one takes so much care in flashing like disabling antivirus, closing down uneccessary processes, fresh reboot, etc etc and installing an app does me for crying out loud.
Ah well, phone is still good so i cant complain.

Would you please explain a little deeper as to Manufacter's marked blocks??
Just for interests sake.
Thanks for the insight

S.K.


OK a little on bad blocks.

When flash memory is fabricated, they are usually fabricated with reduntant blocks to ensure that the required storage is met in the presence of manufacturing faults. Therefore if certain memory blocks do not get fabricated correctly, the memory is still usable as the redundant memory blocks are addressed to work in their place.

This is a cheap method for fabricating NAND flash memories as it increases the yield (the yield is the number of "good" chips to the total number of chips fabricated). If is extremely expensive to ensure all flash memories do not have manufacturing faults as the yield will be low, therefore to increase the yield, bad blocks are just ingnored as there are other usable blocks to take their place

Cheers,

[silent_killa]

Thanks for the info
So basically its cheap ass memory that could go bad for a number of reasons as in my case, a messed up install to the ext rom.

S.K.

[jasjamming]

ummm, no

u didnt mess it up, during manufacturing it got messed up because memory is very sensetive. And it is expensive to remanufacture memory for a few bad blocks, so they manufacture them a little bigger than required to keep the yield high.

when u fot the response form info8 through mtty it shows all the blocks, but the bad ones are replaced by redundant good ones so you do not lose any storage space.

enjoy.....

[silent_killa]

Sweet!!
One final thing, then i'll shut my mouth and the mods can lock this topic.

So i shouldn't have any future problems with flashing then?? I.e if future ROMs use new tools to increase space and perhaps incorporate the ext rom as storage??

S.K.