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[Emmadw]

I'm just trying to find out a little more about my XO, and, like others, want to know what's best if it all goes belly up!

I've read the "Secure Update" page (activated upgrade) - which calls itself "reinstall", but others seem to talk about "reflashing", though from what I can tell, it's the same. Is it?

Also, when people have mentioned "new" USB sticks, is it just that ... a new one, or one that you've previously re-formatted? (On a PC??)

[GregYohn]

Hello!

I reflashed my XO about 8 or more times. I tried using a SD card that I used for other things, but it did not work when reflashing, so I have one just for reflashing now. It works fine when I place it into my USB holder. I take it from the store and use it immediately for reflashing purposes. The proper files are saved from my PC to USB/SD card, before reflashing. I reflashed another XO while visiting the DC XO users group Saturday. It was EASY!

I reflash everything, since I run out of memory or install Sonata incorrectly or some other issue. It is faster reflashing for me and then installing everything in again a 2nd time. I use a mouse with a scroll button in the middle to copy/paste into Terminal to make it fast. Today, I got my Sonata working, my Opera, and Flash installed.

[eden]

I've reflashed a couple of times just to upgrade to a newer build instead of doing the online update.  I used a 1GB Sandisk usb jump drive.  It had other files on it, but I copied them elsewhere and then deleted them from the stick.  I didn't reformat.  I placed the fs.zip and .img files on it, stuck it in the usb slot and then turned on the laptop.  It worked just fine.  You could use a smaller stick than 1GB since the files to flash total less than 300MB.  I recently took the XO with me on a trip as my only laptop but I also took the jump drive with the OS files on it just in case. 

[Emmadw]

All working beautifully thanks

But a quick query. When it did the reformatting & had the display up with coloured squares, mostly it was blue/green; but there was the odd one or two red ones. Are they duff parts of the disk, or are they areas that are reserved for something & aren't written over?

[GregYohn]

Hello!

My guess is that they are reserved for bios or something like that concept. I see the same things with my machine. If the machine had something truly wrong, we could not get it repaired anyway, so if it works fine for us it does not bother me.

[eden]

Regarding the red blocks, there are a few posts I've seen on this forum and the official one that mention them.  There's also a mention on the OLPC wiki.  It appears they might indicate bad blocks in the flash memory, but that this is expected to happen with flash memory.  I personally see two or three as well when I reflash. 

And finally, there is a page on Wikipedia that describes flash memory and specifically the NAND flash that the XO uses:

http://en.wikipedia.org/wiki/Flash_memoryhttp://

"NAND devices also require bad block management by the device driver software, or by a separate controller chip. SD cards, for example, include controller circuitry to perform bad block management and wear leveling. When a logical block is accessed by high-level software, it is mapped to a physical block by the device driver or controller, and a number of blocks on the flash chip are set aside for storing mapping tables to deal with bad blocks. The overall memory capacity gradually shrinks as more blocks are marked as bad.

The error-correcting and detecting checksum will typically correct an error where one bit per 256 bytes (2,048 bits) is incorrect. When this happens, the block is marked bad in a logical block allocation table, and its undamaged contents are copied to a new block and the logical block allocation table is altered accordingly. If more than one bit out of 2,048 is corrupted, the contents are partly lost, i.e. it is no longer possible to reconstruct the original contents. If this is detected when the block is written, the contents may still be available.

Most NAND devices are shipped from the factory with some bad blocks which are typically identified and marked according to a specified bad block marking strategy. By allowing some bad blocks, the manufacturers achieve far higher yields than would be possible if all blocks were tested good. This significantly reduces NAND flash costs and only slightly decreases the storage capacity of the parts."

(Did that fry your brain?  It did mine.  Wonder if I have bad gray cells now too... )

[Emmadw]

I'm sure your grey cells are fine & not fried!

Thanks for the explanation - I figured it wasn't worth worrying!

[neelia_lyn]

how come it's so easy for you to reflash your xo's? might be i'm using a damaged usb? i tried reflashing my xo using usb flash drive but the response i get is boot failed or  can't read nand image. please help!

[GregYohn]

If you do not use a new SD or USB card, do not expect that the REFLASH will work properly! I have tried using a REFORMATTED SD card, but I learned that it just does not work!

Get a small new SD card and you be fine!

[mweisel74]

I had the same issue.  To fix it I reformatted my USB Flash Drive (Freebie from MicorCenter that has been used a lot) and changed from fat to fat32.  Worked like a charm on the next boot.  Thanks for all the information made flashing my daughters XO a breeze.

[greenheron]

I cannot get fs.zip  and .img files to transfer to usb stick-sony 2GB using powerbook with tiger OS. any hints what I'm doing wrong?
Thanks.
 

[GregYohn]

Did you use a brand new never used USB memory stick?

MUST BE BRAND NEW, OR ELSE IT FAILS!

[GLOW]

I've been successful reformatting to FAT32 prior to download.  I didn't need a new stick each time.

[LaPaglia]

Did you use a brand new never used USB memory stick?

MUST BE BRAND NEW, OR ELSE IT FAILS!

I am sorry but while this is interesting its not true. I have used a few old ones. Never had any problems at all.

[GregYohn]

OK, but for me new ones work and used ones never have worked!