Develop Bugs

[Q] Is there a ROM or a way to easily increase the size of /data/data partition?

Are there any roms or other easy ways to increase the size of the partition /data/data on the Droid Incredible? To this day, all I really find are ways to save space in there. That's been covered - everything from Cachemate to not using certain apps. I want to know if there are any roms out there that use space from internal or other areas and reroute them so that /data/data shows more space. Any help would be appreciated.

+1
I've run into this a lot lately. Even my Eris never had this problem.

enigmatl said:
Are there any roms or other easy ways to increase the size of the partition /data/data on the Droid Incredible? To this day, all I really find are ways to save space in there. That's been covered - everything from Cachemate to not using certain apps. I want to know if there are any roms out there that use space from internal or other areas and reroute them so that /data/data shows more space. Any help would be appreciated.
Click to expand...
Click to collapse
No roms do it currently. But its probably doable.
Sent from my ADR6300 using Tapatalk

There is an app on the market called Notenoughspace. I have never used it, but it is supposed to take stuff out of your data/data, and insert it somewhere else. I here it is tricky, so be careful if you use it. I really don't know much about it. The first couple of times I ran into this problem it drove me crazy. Have you read all of the threads for what causes this? Stay away from Facebook. If you sync contacts in Facebook it can cause this. I am a crackflasher, so I rarely run into the problem. I don't think that a Rom can fix this, but I am a newb myself. Really just wanted TP help since I saw your disgruntled post in the developers section....good luck

Thanks for the reply. But here's the thing. Please let's not go into the likes of notenoughspace and cachemate and whiping out facebook. This is what people say in EVERY thread on this from the beginning of the droid incredible.
I'm not looking for a solution that at best can let an extra app or 2 get installed on the droid incredible. I'm looking for a way to INCREASE the size of the /data/data partition by way of taking some unused space from other areas like system or cache or better yet, from that pointless internal storage (for all the SD card users).
There is a lot of extra space on these phones. Thus it is nonsensical to have a measly 150mb to use in that area.
AS this phone is for a friend (and I generally do the upgrading or fixing), I do not experience this on my photon nor do I experience it on my Iconia tab. There was a limit for /data/data on my evo but it was about twice the Droid Incredible I believe.
So this most likely has to be a partition issue. Is there really no fix for it? Since it's not a hardware limit, I'm surprised as I've seen some out of this world ROMs for the device (like Skyraider's which I hoped would make it to the Evo when I had that).

enigmatl said:
Thanks for the reply. But here's the thing. Please let's not go into the likes of notenoughspace and cachemate and whiping out facebook. This is what people say in EVERY thread on this from the beginning of the droid incredible.
I'm not looking for a solution that at best can let an extra app or 2 get installed on the droid incredible. I'm looking for a way to INCREASE the size of the /data/data partition by way of taking some unused space from other areas like system or cache or better yet, from that pointless internal storage (for all the SD card users).
There is a lot of extra space on these phones. Thus it is nonsensical to have a measly 150mb to use in that area.
AS this phone is for a friend (and I generally do the upgrading or fixing), I do not experience this on my photon nor do I experience it on my Iconia tab. There was a limit for /data/data on my evo but it was about twice the Droid Incredible I believe.
So this most likely has to be a partition issue. Is there really no fix for it? Since it's not a hardware limit, I'm surprised as I've seen some out of this world ROMs for the device (like Skyraider's which I hoped would make it to the Evo when I had that).
Click to expand...
Click to collapse
I have had the same problem, and I haven't seen any roms that come close to solving it. And there is no quick and easy solution.
The best work around I could find was to mod the stock rom and add Dark Tremor's APP2SD, and use notenoughspace.
With dtapps2sd you have to partiton the SD card so that you have a ext3 partition on it that can be mounted and apps can be ran from it. It does this for /data/app and a couple of other folders.
Notenoughspace will let you move folders in /data/data to the sd partition that dtapps2sd has mounted, and that survive through a reboot. The extra partition option is what you would use, not the NES partition.
Using this work around I have about 300 apps on my phone, and about 70mb free in /data/data.
My Android version is GB 2.3.4 (build 4.06.605.3).

enigmatl said:
Are there any roms or other easy ways to increase the size of the partition /data/data on the Droid Incredible? To this day, all I really find are ways to save space in there. That's been covered - everything from Cachemate to not using certain apps. I want to know if there are any roms out there that use space from internal or other areas and reroute them so that /data/data shows more space. Any help would be appreciated.
Click to expand...
Click to collapse
Bootmanager will install the whole rom on /sdcard or emmc storage and as an added bonus, /data and /data/data are all in one image so you have shared space. By default you have 950 MB to share for apps and app data. As an added bonus you have the ability to boot multiple roms and have them all loaded at once. It's available on the market and the devs who made it are awesome. However it costs a few dollars.
If you don't want to go that route then it's possible to create an image on the sdcard or emmc and symlink it to /data/data and you could set the size of the file. Then the ramdisk would need to be modified and maybe a couple of things done on the rom. You asked for an easy way and this is one but not easy though. Bootmanager is pretty easy though and no coding changes need to be done to the roms and it will leave your original rom intact.

I've been wondering about this as well.
I've tried a couple different approaches, and ended up sticking with one: it takes some setup overhead for every ROM I install, but it helps a lot.
I ended up deleting the datadata mount from init.inc.rc in boot.img (get ROM, unpack, edit init.inc.rc, repack, flash), and booting in recovery mode to move the data from ([email protected])/ over to (mmcblk0p1)/data (which is now just a subdir on the 768MB /data partition.)
Initial tests repartitioning mmcblk0 (houses /data, /cache, and /emmc) to make /data larger for this purpose didn't work out well: the bootloader rewrites the MBR/partition table when it finds that they don't match metrics it likes. /emmc can not really be reformatted because the bootloader updates some bits that it expects to be FAT32 on boot time as well, corrupting other filesystems.
Why on earth HTC would ship a phone in this day and age with such a crippled storage layout is beyond me.

DHowett said:
I've been wondering about this as well.
I've tried a couple different approaches, and ended up sticking with one: it takes some setup overhead for every ROM I install, but it helps a lot.
I ended up deleting the datadata mount from init.inc.rc in boot.img (get ROM, unpack, edit init.inc.rc, repack, flash), and booting in recovery mode to move the data from ([email protected])/ over to (mmcblk0p1)/data (which is now just a subdir on the 768MB /data partition.)
Initial tests repartitioning mmcblk0 (houses /data, /cache, and /emmc) to make /data larger for this purpose didn't work out well: the bootloader rewrites the MBR/partition table when it finds that they don't match metrics it likes. /emmc can not really be reformatted because the bootloader updates some bits that it expects to be FAT32 on boot time as well, corrupting other filesystems.
Why on earth HTC would ship a phone in this day and age with such a crippled storage layout is beyond me.
Click to expand...
Click to collapse
That doesn't sound too difficult (i moved CM7 from emmc img to the actual phone partitions so that should be pretty simple). The only downside is you do lose space for apps (easily solved with apps2sd). I haven't seen you around since you posted your idea for multiboot. Been busy?
Well, the emmc method would be a loopback image which would not touch the fat32 filesystem.
Or if you're doing nightlies for instance once you mod the boot.img just add it to each new nightly.

Would Conap's dual boot work the same way? I am comfortable with this, and all the coding is intimidating for this newb. Would one of you smarter members put out a small guide as to exactly how to do this. I know it is time consuming, but it would really be worth it to us low lifes. Thanks

How can you do this?
DHowett said:
I've been wondering about this as well.
I've tried a couple different approaches, and ended up sticking with one: it takes some setup overhead for every ROM I install, but it helps a lot.
I ended up deleting the datadata mount from init.inc.rc in boot.img (get ROM, unpack, edit init.inc.rc, repack, flash), and booting in recovery mode to move the data from ([email protected])/ over to (mmcblk0p1)/data (which is now just a subdir on the 768MB /data partition.)
Initial tests repartitioning mmcblk0 (houses /data, /cache, and /emmc) to make /data larger for this purpose didn't work out well: the bootloader rewrites the MBR/partition table when it finds that they don't match metrics it likes. /emmc can not really be reformatted because the bootloader updates some bits that it expects to be FAT32 on boot time as well, corrupting other filesystems.
Why on earth HTC would ship a phone in this day and age with such a crippled storage layout is beyond me.
Click to expand...
Click to collapse
Wow, that sounds like a great idea. Like the above poster, can I also ask if someone who knows how would write up some instructions on how to to this? It certainly would be appreciated by many! With Gingerbread, there's not much Incredible users can do about the tiny /data size. Thanks!

I'm encountering this issue with 384MB of phone storage free and nearly 4GB of SD free. When I checked, I only had 14.5MB free in /data/data. 150MB for this is ridiculous! I would appreciate any fix, preferably one I can set and forget (don't want to have to constantly move or create symlinks for ever new app I install).

possible fix
You should check out jermaine151's Stock+ version 2.1. http://forum.xda-developers.com/show....php?t=1260994. I can't personally vouch for it as he just released it and it's a little late to start reinstalling everything, but it looks promising.

[Q] Arc's /cache partition

Hey,
I've got Arconium ICS rom installed on my Xperia Arc. I'm running low on internal memory, and while trying to find more space on the device I've found this:
Code:
Filesystem Size Used Available Use% Mounted on
/dev/block/mtdblock2 225.0M 1.1M 223.9M 1% /cache
So my question is - what is the cache partition used for on ICS? How big should it be? I found this in the description of some Nexus HD ICS rom:
Cache partition (/dev/block/mtdblock4) is only used by CWM.
Cache partition size is not important because the data partition (/dev/block/mtdblock5) is used as the cache space when running Android.
Click to expand...
Click to collapse
Of course partitions path varies, but the info seems to be relevant.
And a final question - fdisk doesn't seem to work (getting "fdisk: can't read from" error) - how do I go about changing partition table?

To my knowledge (based mostly on HTC phones), in normal use the cache partition is used for downloading apps prior to installing, and for downloading OTA updates (which is why it's so big).
If youre running custom ROMs then this partition doesnt need to be anything like this size, because youre not going to be installing OTA updates. HTC desire owners resize this down to as little as 5meg (though this seems low to me, IMO it should be at least as big as the biggest app youre ever likely to install, so i'd say 25-50 meg is a safer bet.
Now, i have no idea how CWM works, so if this is using the partition to perform installs or nandroid backups or something then your probably wouldnt want to make it much smaller.
There is also a lot of space which could be freed up on the system partition, particularly if youre using a stripped down ROM.
All of the above is all well and good, if there is a way of changing the Arc's partition table. I have no idea how this is done, or if it is even possible. So would love someone who knows about this stuff to respond. BUT: i very much doubt FDISK (you mean windows fdisk?!?!?) is the answer - at the very least i'd expect that you'd need a specially modified kernel in order to boot with a modified partition table. The fact that it fdisk with an error instead of giving it a try is probably the only reason your phone still boots.

Why do I need to partition my sd card for ICS roms?

All of the new ICS roms talk in their instructions to partition your sd card. Some also have a non partition version for those that wish to not partition but those releases take longer to come out.
So why should I partition? I am asking in a general I really want to know why as on all of the rom release pages it just says to partition but no one every talks about why. Why do the newer roms require partitions while the 2.x Android roms never needed this.

Can't anyone let me know?

A lot of ROMs in 2.x support DarkTremor which allows many of the ROMs files to go onto a separate partition on the SD Card. This speeds up the phones response time as you run various apps.
This is most likely why the ICS builds are asking for you to partition the SD Card since they are automatically enabling this which is unlike the 2.. builds in which it was an option.
Doc

DocEsq said:
A lot of ROMs in 2.x support DarkTremor which allows many of the ROMs files to go onto a separate partition on the SD Card. This speeds up the phones response time as you run various apps.
This is most likely why the ICS builds are asking for you to partition the SD Card since they are automatically enabling this which is unlike the 2.. builds in which it was an option.
Doc
Click to expand...
Click to collapse
Is this new automatic thing part of ICS or just something differently the rom developers are now doing?
Was DarkTremor built into the 2.x roms? When I first moved from stock to Cyanogen all I remember doing was wiping and installing the zip file, never did anything extra.

LordJezo said:
Is this new automatic thing part of ICS or just something differently the rom developers are now doing?
Was DarkTremor built into the 2.x roms? When I first moved from stock to Cyanogen all I remember doing was wiping and installing the zip file, never did anything extra.
Click to expand...
Click to collapse
I believe that this is something being put in by the developers. The ICS you get from HTC, LG, Samsung etc.. does not have this.
DarkTremor was built into a lot of the 2.x roms and would only become active if you you had the SD Card partitioned properly. It is in Cyanogen but it is something that you did not need to use if you did not want to.
There are some good tutorials out there if you want to give it a try. The big advantages are that it speeds up your phone and frees up precious space on your internal memory.
Doc

I believe the simple answer is that ICS has a bigger footprint and therefore requires more internal system capacity. The phones that come stock with ICS have more system capacity than our EVO 4G. A2sd and an ext partition effectively expand the system partition so that these larger footprints will work on our phones.
Non-a2sd versions take longer because the dev has to figure out how to get ICS working with "insufficient" capacity.
Another development to look at is firerat's mtd mod that allows one to reconfigure the system, cache, and consequently data partitions.
Sent from my NookColor using Tapatalk 2

dcharleyultra said:
I believe the simple answer is that ICS has a bigger footprint and therefore requires more internal system capacity. The phones that come stock with ICS have more system capacity than our EVO 4G. A2sd and an ext partition effectively expand the system partition so that these larger footprints will work on our phones.
Non-a2sd versions take longer because the dev has to figure out how to get ICS working with "insufficient" capacity.
Another development to look at is firerat's mtd mod that allows one to reconfigure the system, cache, and consequently data partitions.
Click to expand...
Click to collapse
Thanks! That was exactly what I was looking for.
When people use in in GB roms is it just them trying to optimize things better by freeing up system memory by utilizing sd space?

LordJezo said:
Thanks! That was exactly what I was looking for.
When people use in in GB roms is it just them trying to optimize things better by freeing up system memory by utilizing sd space?
Click to expand...
Click to collapse
Yes, that's what I think.
Sent from my NookColor using Tapatalk 2

That is why I partitioned my drive (to move apps to my sd card and to free up space on the phone). I am on the MikG ROM.
Sent from my PC36100 using xda premium

1TonyC said:
That is why I partitioned my drive (to move apps to my sd card and to free up space on the phone). I am on the MikG ROM.
Click to expand...
Click to collapse
Why would you need to partition the sd card to move apps? That's a built in feature of GB.
Or do you mean system apps?

I was constantly getting alerts that I was running out of internal memory. This was after I transferred as many apps as I could to the sd card.
So I partitioned my sd card and flashed the MikG ROM. No more memory problems .
Sent from my PC36100 using xda premium

Partitioning for apps2sd is not to move ur apps to SD card. It will automatically install ALL apps downloaded from play store to the SD. No need to move anything! Its like adding internal memory to our phones! I was hesitant at first but now I wouldn't do it any other way. I noticed a nice increase in performance on ics roms and I can now download whatever the hell I want and not worry about bogging down my internal memory
Sent from my D.I.R.T.y CM9'd EVO 4G using xda premium!

Rather than posting a new thread, I'll ask my question here since it is somewhat relevant to the conversation.
I'm at work while I was updating to jmztaylor's latest nightly, so I do not want to backup my SD onto my work computer. Can apps2sd be flashed at any point after flashing the ROM or does it have to be at the same time as flashing the ROM?

Jaxp3r said:
Rather than posting a new thread, I'll ask my question here since it is somewhat relevant to the conversation.
I'm at work while I was updating to jmztaylor's latest nightly, so I do not want to backup my SD onto my work computer. Can apps2sd be flashed at any point after flashing the ROM or does it have to be at the same time as flashing the ROM?
Click to expand...
Click to collapse
It can be done later.

Captain_Throwback said:
It can be done later.
Click to expand...
Click to collapse
Great, thanks for the info!

The main difference between the built-in moving of apps and the partition is where the apps go.
With GB's moving (a2sd) the .apk file is moved to a directory on your SD card called .android-secure. The big con to this is that if your SD isn't mounted (for example, if you're moving files from your computer, or on the initial error check on boot), you can't access these apps. You also cannot use any widgets an app might have if it's been moved to .android-secure.
If you have a partition (ext3 generally) then it's a different story. Generally, what happens is that the /data/app directory in your internal storage is symlinked to your partition, /ext. (I think it's /ext/data/app, but I can't remember and haven't used the sd partition for a bit). Pros to this one are much more space, since assuming you have the space and your SD is fast enough you can also symlink your appdata and dalvik-cache. Plus, you are able to use widgets because Android thinks the apps are installed to the internal data. One major con is that you can potentially reduce your SD card's life, since it will be reading and writing a lot more from that portion of it.
And a symlink explanation: In a sense, it points one directory to another area of the filesystem. When I was partitioned Root Explorer showed my symlinked /data/app as this: "/data/app > /ext/data/app". It's a way to have parts of the filesystem "appear" in other areas without having to copy/paste. I've used it to get a few directories to sync to Dropbox without having to keep spare copies of my files in the main Dropbox ones.

Be careful. I just did it an hour ago and everything disappeared from my sd card. So pissed.
Sent from my PC36100 using xda premium

What are partitions..
SLB9884 said:
Be careful. I just did it an hour ago and everything disappeared from my sd card. So pissed.
Sent from my PC36100 using xda premium
Click to expand...
Click to collapse
That is because when you re-partition your card (or hard drive,etc..) it basically wipes it. What you are doing is redefining the very volumes that take up space on your card and giving them a starting and ending block address based on the size of the card and the defined size of the partition. You can think of it has a two pieces of glass and you are pouring colored sand in. You pour red in and get your data partition, then you pour in green and get your swap partition so on. Eventually all partitions are defined and ideally will make the most use of the total space on your card.
So when you partition, it's very low level and requires abandoning all data and prior formats on the card unless you are using some special software that attempts to adjust the sizes of the partitions.
Somewhere at the beginning of your card is a small sector that lists all the partitions and their starting/ending blocks, plus other relevant informationj.
So if you plan to partition, you need to back up the data first to your pc or what not.

Storage
Because its an entire system you'll want to to save space on your card, make a backup of any important files because its gonna wipe it and you cant undo it

Here's a couple of great guides for a2sd. Once I finally did my phone performed much better.
http://therootofallevo.com/2011/04/10-step-guide-properly-set-darktremors-a2sd/
http://androplasty.com/2011/08/mini-guide-how-to-re-partition-your-sd-card/

Any way to reclaim integrated memory space?

Hi guys,
I was wondering, now that I no longer use a TouchWiz-based ROM, if there's an easy way to reclaim the "lost" space available in the /system folder after flashing a now much small ROM. I know TW-based ROMs use at least 1GB of space, if not more, but my current ROM barely pushes 200MB used of the /system folder, leaving with me a lot of unused space I would like to use for the integrated storage.
Regards

gonXed said:
Hi guys,
I was wondering, now that I no longer use a TouchWiz-based ROM, if there's an easy way to reclaim the "lost" space available in the /system folder after flashing a now much small ROM. I know TW-based ROMs use at least 1GB of space, if not more, but my current ROM barely pushes 200MB used of the /system folder, leaving with me a lot of unused space I would like to use for the integrated storage.
Regards
Click to expand...
Click to collapse
It's about partitions, no matter what rom you use.
Imagine you have a 1gig harddisk. You partitioned it into four 250gig harddisks as C,D,E,F
You have installed Windows 7 on C drive but then you installed XP to save some spaces for the harddisks D,E,F
Would it be possible? No!
You have to resize all the partitions which would cause you bigger problems.

I think is something to do with the pit files.
I read something about Sammy offering a new Flash for the s4 with some Chinese rom that enables them to get another couple gig space whilst losing some trash.
I hope we can get something similar either officially or through our devs
Sent from my GT-N7105 using xda app-developers app

[email protected] said:
It's about partitions, no matter what rom you use.
Imagine you have a 1gig harddisk. You partitioned it into four 250gig harddisks as C,D,E,F
You have installed Windows 7 on C drive but then you installed XP to save some spaces for the harddisks D,E,F
Would it be possible? No!
You have to resize all the partitions which would cause you bigger problems.
Click to expand...
Click to collapse
I don't think I follow you. You're telling me resizing partitions is not possible? Theoretically, it is with any type of filesystem and partition table that supports differently sized partitions/blocks. I'm not asking if it's possible to do it, I'm asking if it's possible to do it in an easy way.
My question wasn't if it was possible to do it with the new ROM, I was asking if it was possible to do, now that I have some abundant disk space for /system.
On my Nokia N900 this was extremely straightforward as I basically had the full GNU coreutils available - and with some hacking I resized the partitions to better fit my needs - and even flashed the fat32 filesystem to ext3 while I was at it.
And since it's possible with S4 as 3vo3d mentioned, there's no reason it shouldn't with the GN2.

gonXed said:
I don't think I follow you. You're telling me resizing partitions is not possible? Theoretically, it is with any type of filesystem and partition table that supports differently sized partitions/blocks. I'm not asking if it's possible to do it, I'm asking if it's possible to do it in an easy way.
My question wasn't if it was possible to do it with the new ROM, I was asking if it was possible to do, now that I have some abundant disk space for /system.
On my Nokia N900 this was extremely straightforward as I basically had the full GNU coreutils available - and with some hacking I resized the partitions to better fit my needs - and even flashed the fat32 filesystem to ext3 while I was at it.
And since it's possible with S4 as 3vo3d mentioned, there's no reason it shouldn't with the GN2.
Click to expand...
Click to collapse
No, I didn't say that you cannot resize partitions
I said that you cannot gain more space in other partitions by just installing a lighter OS. I said exactly what you said in the rest.

[Q] Removed bad NAND, phone won't boot

My DInc NAND went bad, it became read-only and could not be written to. This is the 8GB NAND that houses /data, /cache, and /emmc partitions.
Tiny came out with a nice little patch for me, to patch custom ROMs in order to use partitions on the physical SD card as /data and /cache. That worked well for awhile, though with an occasional glitch where I'd get random factory resets. Anyway, I don't use the DInc anymore, thinking to fix it with a new motherboard from a cracked screen phone or something and selling it. Probably won't hardly go for anything, but it's not doing me much good sitting around. With that plan in mind, I decided to pull the bad NAND chip just to see how hard that is. Got a new SMD rework station and figured it's something I could goof off with on a boring Saturday morning. It came out without much fuss.
Anyhow, now the phone won't boot CM11 with the NAND chip missing. The phone does try to boot because /boot and /system are on a different NAND chip, but now it's not seeing /data or /cache on the physical SD card, at least that's my guess. I do plan to replace the motherboard, but mainly just curious why it no longer works. Is because of partition order? Because I lost 3 bad read-only partitions, the partition count is now off?
I knew it was possible I'd end up killing my DInc by pulling the bad NAND and I'm not too broken up about it. Mainly just curious why it no longer works, and kind of wondering if it's possible to fix.

Figured out some stuff.
With bad NAND chip removed, MicroSD takes its place as /dev/block/mmcblk0.
In a way, this is kind of good. If I make 3 partitions on MicroSD, I no longer need to use Tiny's patch or a custom recovery to map everything to mmcblk1. I can now use the same TWRP recovery everyone else uses and it recognizes mmcblk0p1 as /data, mmcblk0p2 as /cache, and mmcblk0p3 as /emmc.
Even CM11 and Evervolve 4.4.4 work without any patch and recognizes mmcblk0p1 as /data, mmcblk0p2 as /cache.
However, neither ROM maps mmcblk0p3 to anything. /sdcard, /emmc, /storage/sdcard0, /storage/sdcard1, none of those are mapped to mmcblk0p3.
UPDATE: Figured it out. Had to change /devices/platform/msm_sdcc.3/mmc_host/mmc2 to /devices/platform/msm_sdcc.2/mmc_host/mmc1 in fstab.inc.

just wondering, how are you determining that you have a bad nand chip? are you running any sort of test that can tell you definitely?
I have 3 dincs, 2 that I bought refurbished and used on eBay that seem to have been repaired(the water damage sticker has been tripped). I always assumed that the HTC Dinc was just a weak, limited and terrible phone due to bad 1st generation design. My phones had been prone to rebooting and errors due to the small system app partition. But they have worked reasonably well for me the last 3-4 years.
I upgraded all 3 to the latest evervolv 4.0 version with TWRP 2.6.3 and 2 of the 3 seem to have taken the upgrade well. have the 3rd one constantly reboots when trying to access anything via the play store. The internal 8 gig EMMC card had disappeared from it and also at times, the wifi controller disappears. I down graded it all the way back to Tiny 5-16(which it had run for the last 2 years) and it stabilized for the most part with the EMMC being seen again. Do you think the missing EMMC partition is a sure indicator that the memory on the phone is bad?

Here is the full thread:
http://forum.xda-developers.com/showthread.php?t=2175346
But long story short, I couldn't write to the eMMC chip at all. Not only my /emmc partition was read-only like some people had happen and could fix with fsck_msdos, but my entire eMMC chip, which means /data, /cache, and /emmc were read-only. RUU couldn't fix it, fsck couldn't fix it, and even attempting to remove and rebuild partitions using parted couldn't fix it.
I'm not sure if losing the /emmc partition by itself means the chip is bad. The chip also has the /data and /cache partitions. I'd think if either of those go offline, all your apps will start to FC. Although you did say it constantly reboots, and I think that's possible when /data and /cache go offline. I think mine actually did reboot an awful lot on its own before the eMMC chip went completely bad. You might try running e2fsck -c to check for bad blocks.