PRS-T1 Questions regarding Repartitioning PRS T1

[ireadbook]

Hi, this is my first post here, it may be a bit long, but I want to make my question more clearer. First of all, thanks to porkupan for making T1 a more interesting device, and thanks to everyone contributing to this forum!

PRS T1 is my first Android device, also my first Eink device. So I'm still not quite familiar with Android OS, but i use Linux for my desktop, so i'm ok with command line.

Some of my assupmtions may be wrong, please feel free to correct me at will.

I have read these threads
https://wiki.mobileread.com/wiki/PRST...itioning_Guide
https://www.mobileread.com/forums/sho...137&perpage=40
https://www.mobileread.com/forums/sho...132&perpage=40
https://www.mobileread.com/forums/sho...199&perpage=40

here's my understanding:

The default T1 partition table looks like this:
mmcblk2p1 ext4 "Recovery" 10MB (linux tree) CANNOT TOUCH
mmcblk2p2 ROMfs 10MB (linux tree) CANNOT TOUCH
mmcblk2p3 Extended partition
+ mmcblk2p5 ROMfs fonts
+ mmcblk2p6 ext2 dictionarys
+ mmcblk2p7 FAT16 "SETTING " 10MB (reader for PC)
+ mmcblk2p8 ext2 "preload" 40MB (userguide + ebooks)
+ mmcblk2p9 ext4(with journal) "data" 48MB (android data)
+ mmcblk2p10 ext2 "system" 128MB (android system)
mmcblk2p4 FAT32 "READER " 1.4GB (internal memory)

(WARNING! THIS IS NOT A DETAILED PROCEDURE, PLEASE CHECK THE LINKS ABOVE)
the whole point is to make the "data" area larger, so all I have to do is shrink the "READER" partition -> enlarge "Extended partition" -> move "system" to the end of "Extended partition" -> enlarge "data" partition -> REBOOT PRS-T1 -> restore system.img back with dd -> mkfs.ext4 -L "data" /dev/mmcblk2p9 -> mkdosfs -n "READER" -F 32 /dev/mmcblk2p4 -> END Is that right?

1. If that is the case, then how's "rooting" have anything to do with this? since nothing has changed except the partition table.
2. Some suggest that T1 needs to be "unrooted" first, some say "root" the device before repartitioning, what is the right thing to do?

3. According to uboot, 5-8 can keep the way it is, just rembered the old partition table and recreate it at the same position will be ok.

4. Also according to uboot,

"always work with sector units and align to cyl=64x512 Bytes"

,then I double checked this page about Partition_Alignment

seemed to me uboot's partition table (including uboot's old one) is not a proper alignment, or I'm wrong about this?

5. According to rupor

"making sure operation is committed before doing next one (tool allows you to commit multiple operations in sequence or batch mode - do not use it!)"

does that mean I have to w(write part table) each time when I'm creating a table using fdisk? (like this? n->w->n->w->...) but not just "w" one time, at the end of partition table creation process?

6. In this Complete guide by homeos,

16. format /dev/mmcblk2p9 in ext4 & set volume label
# /sbin/mkfs.ext4 /dev/mmcblk2p9
# /sbin/tune2fs -L data /dev/mmcblk2p9

Why not just `/sbin/mkfs.ext4 -L data /dev/mmcblk2p9`, why separate it into 2 procedure?

7. uboot says there's no need to restore files to "data" & "READER" partition. T1 will regenerate "data" itself. But if I did restored old files from backup using tar (recommended by j0534ng31), will I be able to keep my old apps & settings? does that update.img include gzip compression method for tar? Is T1's CPU fast enough for "tar -cvzf" ?

8. How to do this under Linux, has anybody done this under Linux(or other *nix) before?

9. In that complete guide, it only pointed out COM port need to be 9600 baud, but what about parity mode?

10. How much space do i need on MiniSD card? I have a 1gb card formatted by T1, which is empty now, is that enough to do this job?

11. Which process of repartitioning have failed most people, bricking their device?

12. btw, why Nook Touch doesn't need repartitioning? how big is nook's "data" partition size?

Thank you.

[rupor]

There is T1 package which does repartitioning automatically - you do not have to digest all this information (useful but boring).

http://projects.mobileread.com/reade...upor-resize.7z

Just make sure that you have device with Sony's firmware 1.0.05... preferably in pristine condition You will need SD card in the device, procedure is no different from normal rooting. If you want to speed it up - make sure that you moved all books OFF device

[ireadbook]

Thanks for your reply! I'd love to learn new things, I won't be bored. just backed-up all the partition with dd, using minicom connected to /dev/ttyACM0 under Linux enviroment. All seemed ok so far. I'd love to understand the whole process, it'll make me feel more comfortable knowing "how does it work".


Many people claim wifi function doesn't work properly anymore after update firmware to 1.0.05. And I'm not sure I'll able to restore the device into pristine condition, i'm not sure what have the previous owner done with this t1 before you see. (yes, it's 2nd hand)

[rupor]

You could try "automated" procedure anyway I think - at the beginning of it I take print of partition table, calculate MD5 on it and compare it with MD5 of "pristine" partition tables known to me. If partitions were modified in a way unknown to me - procedure would not do anything. So it should be harmless to try - even for second hand device.

Something like this:

CHECK=`parted -s /dev/mmcblk2 unit s print | tail -n 11 | head -n 10 | md5sum | awk '{ print $1 }'`
if [ "${CHECK}" != "23d3bacd2772baa47a19379e1f4bc84f" -a "${CHECK}" != "601f19a43444ef303bc0a4b81b557272" ]
then
   echo -e "ERROR: Device has wrong partitioning, exiting immediatly ${CHECK}\n" >> $W_LOG

[ireadbook]

ok, now i've successfully repartition-ed my t1, and every app and notes handwritings have been preserved.
mainly following the steps on the wiki and above mentioned links, and i reread rupor's Step by step guide to repartition the device.

3. Worked for me. I dumped all the partitions and reboot several times, and I discovered from md5sums of img file I dumped that p1 p9 p10 changes from every reboot. p2 p5-8 stays the same.

4. uboot's old partition table is exactly like mine, but his new one is not strictly speaking a proper alignment, but it worked anyway.

I repartitioned t1, formatted p4 & p9, dd p10.img back to mmcblk2p10, copy back "data" from p9.img, and "READER" to p4.

The internal memory speed seemed slower than before, copying speed 800k-3MiB/s, or that's just the normal speed?

I haven't change the size of "system"(p10) partition, still 128MiB, is that enough? Will new apps install something into "system" partition? I mounted the p10.img and `df -h` give me "Size:100M Used:95M" 100m=128m??

If I installed something which is oversized (bigger than my Avail. space), will it broke the device? Should I make "system" partition bigger?

[ireadbook]

The update.img I'm using don't have "parted" installed,just fdisk.But thanks anyway. I think the partition table is "pristine" after all, it's exactly the same as uboot's old partition table. That wasn't the main reason that I'm a bit worried, the previous owner maybe already done rooting(still in rooted condition now), repartitioning, and he tried to restored to it's initial state. But I'm over that anyway. Everything worked fine so far.

Is it safe to use the flash packages (enable-adb,restore-set,sd-rescue,rupor-rescue, minimal-root, etc.) now that I've changed partition table of T1?

btw, how did you repartitioned with ADDH? Mounted a dumped image? Or directly operating on T1 with USB cable?

And I checked again on tty, the "system"(p10) partition size is 128MiB, but it's ext2 filesystem reported 100M (95 Used). Should I formatted p10 making it bigger or keep it intact?

Journalling filesystem causes more read/write action, and it'll reduce flash memory's life. Should I convert "data" partition to ext2 again? Or should I just disable journaling using `tune2fs -O ^has_journal /dev/mmcblk2p9`

[rupor]

Keep /system unchanged!

If I remember correctly some restore sets will do DD on /data partition - which means that after restoring you will have to recreate file system (or do proper factory reset), otherwise you would not be able to use all of your data partition. Packages rupor-rescue, rupor-minimal, rupor-enable-adb, rupor-asec, rupor-jailbreak should all work fine - as long as you did not change /system size. You would not be able to apply Sony firmware packages (if any) and you would not be able to do any of my automated procedures which involve repartitioning...

I did repartitioned multiple units using my rescue package to map whole mmcblk2 under Windows. I successfully used various tools (whatever was available at the moment) - you could find links to translation of my original guide in this forum. I do not do it anymore - automated procedure is way easier...

[ireadbook]

So those update packages only touches /data then.
Thank you very much for yourl helpful advices!