Database Users

Booting Android from sd card on Dream/G1

Hi all,
Here are my findings about how to boot android from an SD card, useful for example to test development Android builds without messing your phone. This procedure was inspired by legacy GNU/Linux boot process and then should work on most hardware with a flashable recovery.
########################################
I can't stress enough the fact that this procedure is targeted to experienced user. A good knowledge of linux/android booting process is more than required. This procedure is not meant to be useful to most people given its limitations (no recovery mode, rebuild of boot.img required)
########################################
I won't propose a step by step tutorial as it's better to understand how to do it and adapt the procedure to each need.
Two modifications are required:
1. Declare to mount sd card partitions instead of internal flash volumes. This has to be done in the init.rc script.
For example:
mount yaffs2 [email protected] /system
mount yaffs2 [email protected] /system ro remount
with
mount ext2 /dev/block/mmcblk0p6 /system
2. For some reasons, in the boot process, sd card partitions generally show up later than the mount actions, so it is generally necessary to add a timer in init binary to give to to the kernel to detect sd card partitions before mounting them (adding a sleep(5) after the "A N D R O I D" text in init.c is enough).
Build your special boot.img embedding those two modifications and flash it on the recovery volume of your phone. Now, booting into recovery will launch the system on your sd.
Regards,

I would like to report success on booting the G1 from a system located on sd card (cyanogenmod 4.2.7.1). I will describe the procedure step by steps when every thing is okay.
There is just an issue that you might have encountered during cyanogenmod ROM cooking, all wireless connexions (wifi, BT, GSM) do not work. The same system on flash if okay. I made a diff on boot log messages and the only notable difference is this error :
E/MemoryHeapBase( 83): error opening /dev/pmem_gpu0: Permission denied
E/MemoryHeapBase( 83): error opening /dev/pmem_gpu1: Permission denied
E/MemoryHeapBase( 83): error opening /dev/hw3d: Permission denied
I tried to chmod 0555 /dev/pmem* with no success.... Any idea ?

Although I finally managed to have a usable system, this work is still experimental. Please fell free to test and report success, failures here so I can improve the thing.
Let's see how we can boot a copy of cyanogen ROM 4.2.7.1 located on sd card. The main purpose is to test future ROMs (eclair ?) without messing up your phone...
DISCLAIMER : This procedure is targeted to experienced user. I am not responsible if you loose your data, your phone or your Mom !
Prerequisites are :
- adb and fastboot operationnal on your host computer
- Boot image file boot.img :
http://www28.zippyshare.com/v/19654421/file.html
- files data.cpio.gz, system.cpio.gz (data.cpio.gz and system.cpio.gz are unmodified images of a fresh install of cyanogen ROM that fit the modified boot.img) from :
http://www15.zippyshare.com/v/57489279/file.html
http://www15.zippyshare.com/v/13077582/file.html
1.
Create 3 partitions on sd card. The first one (vfat) is to store your music, videos etc. The second and the third will hold /data and /system. Result shoul look like this :
# fdisk /dev/block/mmcblk0
Command (m for help): p
Disk /dev/block/mmcblk0: 1977 MB, 1977614336 bytes
64 heads, 63 sectors/track, 957 cylinders
Units = cylinders of 4032 * 512 = 2064384 bytes
Device Boot Start End Blocks Id System
/dev/block/mmcblk0p1 1 864 1741792+ c Win95 FAT32 (LBA)
/dev/block/mmcblk0p2 865 903 78624 83 Linux
/dev/block/mmcblk0p3 904 957 108864 83 Linux
Command (m for help):
2.
Copy data.cpio and system.cpio on the first partition of your sd card.
3.
Connect to your device with adb :
adb shell
4.
Mount mmcblk0p2 on temporary folder and extract user.cpio.gz archive :
mkdir /dev/tmp
mount /dev/block/mmcblk0p2 /dev/tmp
cd /dev/tmp
gunzip -c /sdcard/data.cpio.gz | cpio -i
cd /
umount /dev/tmp
5.
Mount mmcblk0p3 on temporary folder and extract system.cpio.gz archive :
mount /dev/block/mmcblk0p3 /dev/tmp
cd /dev/tmp
gunzip -c /sdcard/system.cpio.gz | cpio -i
cd /
umount /dev/tmp
6.
Reboot the phone in bootloader :
adb reboot bootloader
7.
Boot the phone with custom boot image :
unzip boot.img.zip
fastboot boot boot.img
Reports are welcome !

I haven't tried this, but great idea. Well done.
Maybe a nice additional idea would be a boot-menu style idea. Eg, detect OS on mem card and display a menu of "Internal" or "SD Card"?

I'm on it but as it will imply flashing people's phone, I need more testing and suggestions from experienced hackers. I only own my G1 for 5 days...

I acytually just started a thread about this in the Dream development subforum!
Some suggestions:
-Use a recovery image to boot the ROM on the sd card (look at modifying the CM recovery image) if this is possible. This way, you can boot from sd card when you want to, by booting into recovery image, without interfering with the flashed rom at all. No worries that flashin a new rom will require a reflash of your bootloader. Also, you can use the ROM installed in flash after a reboot without any hassle, which would be very useful when testing a ROM from the SD if it doesn't work very well and you need a working phone.
-Have the /data and /system-partition as folders on the 4th partition on the SD card, or as logical volumes on a primary one. Why?
Well, many people have their sd-cards set up with fat, extX, swap in that order. The partition layout you have described here simply isn't compatible with that, and will require a separate SD card just for this testing (which everyone might not have).
I must say, I think this is a GREAT idea! I so often want to test a few ROMS, but often they don't get the test-time they deserve because I need to swicth back to my working environment for job/uni the day after. This would be a great way to test a ROM thoroughly. And also it would be the best way to give a ROM a quick testdrive. switchroming back and forth is, for all its simplicity, hassle.

Using the recovery is the only way I found at the moment to boot from the sd card and was about to extend cm recovery with a dedicated menu Nevertheless, there will be a limitation with that: it will not be possible to use a different kernel for the system on sd as it will have to use the kernel of the recovery... Anyway, many custom roms around here use cm kernel (even those I saw with eclair) so it is not so problematic I think (tested Eugene373 AOSP20 yesterday). Anyway, it is possible to adapt the recovery with a test kernel...
I think I found a workaround for sd partitionning scheme pb, using bind mounts but I have not tested already. I will work on it this WE.

If I remember correctly you can use the command "reboot recovery" from the recovery shell to reboot again into recovery. It could mean that it is possible to choose what (kernel) to boot after the reboot. Even cyanogenmod has made quite a few changes to the kernel since the recovery image came out, and I think it would not be a very good solution to use the same kernel as the recovery image for all ROMs loaded via SD. (Especially the Hero ones won't work at all, I'm afraid.
It could also be possible maybe, to tweak the built-in bootloader into booting form either SD-card or from the internal flash? It already has the possibility to boot different things on different keypresses (home for recovery mode, and camera for fastboot). I have (again) no idea of its capabilities for reading anything off of the sd card, though.

I get your point naguz . I am not satisfied either with the solution of using the recovery kernel to boot the system on sd. I found that it adds quite much complexity to the init process: I tweaked the recovery executable to add an entry to boot from sd but I faced troubles in services startup and pre-init definitions. I think that the solution of using the recovery menu to choose to boot from sd have to be abandoned as it will require heavy additional changes to the init.rc scripts of the second system and will break its advanced features.
The ideal solution (as you suggested) would be to tweak the bootloader to boot natively from the sd card but unfortunately, we do not have the sources of the SPL (tell me if I am wrong) so it is definitely not possible.
The remaining solution is to use the recovery partition to flash the boot image of the second system. I works well, just press the home key and the second system boots ! The drawback is that you do not have recovery any more... Personnaly, I don't find that so problematic as I is still possible to boot a recovery image with fastboot when needed, so I think I will stick to this solution. I somebody have another solution, I am ok to investigate...

Aha, it makes sense that booting the sd directly from recovery mode would mess something up. I would think some of the same problems would be faced when booting the kernel from the recovery partiotion, doesn't it look like a different device to the kernel? Well, if it works, it works.
Regarding the source of the SPL, I have no idea, but I know hyakuro (a (former?) user here) has released a modified one. Trying to get in touch with him
As for the latest method: Is the recovery partiotion big enough to hold both the recovery image AND the kernel? If so, one could maybe have both. Maybe make a new "recovery image" that can either boot from sd or boot recovery image? Just throwing out ideas here.
Personally I don't see the big problem with not having a recovery image, as I would (in a dual-boot scenario) already have another, working install on the flash that I could use if the one booted from sd wasn't good enough. Re-flashing the recovery image could also be done from the working ROM in flash, for those without the SDK tools.
I think, however, that quite a few people will object to not having a recovery image.
Btw, was your latest working test done with one (4th) partition on the sd card for loading the ROM from SD? If so, new instructions please. I'd like to give it a try.

I think that it is technically impossible to boot directly from the sd, even with the sources of the SPL as drivers are required to drive the sd that can not be included in a SPL. It is the same issue on PC with PCMCIA network cards for instance. IPL+SPL has to be seen more or less like a simple BIOS...
The recovery partition size is not a matter her. The problem is the lack of control over what has to be booted as the only action we can make in the SPL is the HOME key to choose a regular boot or a recovery boot (the system on SD here). I think I have a good knowledge now of the boot process and I think we can not got further than that, despitely...
I am now trying to have /data and /system on the same partition, mount them on /mnt and bind mount each directory on /system and /data but with no succes . investigating....

Okay, bind mounting was a dumb idea of mine. The solution is to create an extended partition with 2 logical drives in it, so partitions are:
[1-3] FAT and/or EXTX and/or swap as needed (I have personnaly just one partition here)
4 extended
5 ext2 for /data
6 ext2 for /system
Now its time to bake a boot.img with the kernel of the system on the sd card + the ramdisk. I do not explain how to do that, google knows :
1.
In the ramdisk image, put my modified init program attached hereater
2.
In the init.rc script, change the lines that mount /data and /system :
mount yaffs2 [email protected] /system
mount yaffs2 [email protected] /system ro remount
with
mount ext2 /dev/block/mmcblk0p6 /system
and
mount yaffs2 [email protected] /data nosuid nodev
with
mount ext2 /dev/block/mmcblk0p5 /data
Flash boot.img on the recovery and reboot in recovery... That's all.

Jahrome,
Trying the idea on the HTC has a subtle difference. So I'm curious what change you put in the /init process.
Lets say the image one wants to use is the 'eclair' branch. This branch uses vold, so the block device, such as '/dev/block/mmcblk0p#', does not appear to be created until the vold service is started, which is after the init.rc mount operations. So the mount proposed does not work.
Curious what changes you made to the init process that might give me some ideas of what might be the simplest change. It seems that there is a relatively easy solution, that I don't yet see.
Ideas (or additional questions to clarrify) appreciated...

Hi Dale !
On which HTC are you trying the trick ?
First your trouble is not related to eclair as I successfully booted eclair on my G1 with this trick. You need to add a timeout in init so as it waits for the kernel to detect sd card partitions (need to recompile init, or use my recompiled init).
Vold has nothing to do at this point
Hope this helps

Init Delay for SDisk
Thanks for the reply. That's what I needed, it seems so ungraceful.
I thought vold was enabling something to make the kernel's discovery of the SD partitions. It is "by coincidence" that the log of the vold occured shortly before the adding of the block-device event. My apologies for not recognizing the coincidence of the log entries.
I had hoped the solution was a bit more "graceful", though I can't say what that would be or why a sleep is "ungraceful". I would like a "mount retry for n-seconds" option in the init.rc, that would be slick. Nonetheless I will add in a sleep-spin-check for a few seconds.
For the record, we are discussing the change to:
android-source: .../system/core/init/init.c
code-routine: main()
code-location: Somewhere after the "A N D R O I D" text
code-change: add in a sleep spin-check of some sort
I appreciate the comment that all we need is just a sleep. I think this completes the thread?!

Most interesting...
This is something akin to how I am using my company's Android solution for the Beagle Board...
In that environment, the entire kernel and rootfs are located on a SD/MMC card. The environment variables and boot script are stored in the NAND chip
through a "setenv" command. The U-boot monitor on the hardware defaults to run the boot script unless there is any user interaction. This image can then be converted into a typical distribution that can be flashed and ran without the SD card...
I have wondered about the implementation of this approach on my G1, but I have not had time to test it out. It is good to see that there are others that are interested in this as well...
I will be following this thread and will try to help in any way if I can... meaning if I can get some free time...
If you are interested in our Beagle Board solution, it is open source and can be found by a simple Google search using "Android rowboat"...
L8R...

very easy fix.
rename the /init to /init.android (or whatever you like)
create an init script. have it prompt on boot too boot from sd or internal. symlink the init.rc from /system. That way you only need one boot.img for multiple builds. We've been doing this a really long time on the android on vogue project. My development phone is simple, I hold down the menu button if I want to boot from the sdcard otherwise it boots from the internal.
Oh and don't worry about this.
jahrome said:
log messages and the only notable difference is this error :
E/MemoryHeapBase( 83): error opening /dev/pmem_gpu0: Permission denied
E/MemoryHeapBase( 83): error opening /dev/pmem_gpu1: Permission denied
E/MemoryHeapBase( 83): error opening /dev/hw3d: Permission denied
Click to expand...
Click to collapse
That's just that you don't have HW3D enabled in your kernel. It's important to note that if you're trying to use multiple builds that eclair with 3d and donut use different kernels.

Exactly the vogue and kaiser have been doing this for ages. If you want you can also boot ext2 and squashfs images. It's pretty simple stuff.

Anyone have a backup of the files in post #3? I've been trying this solution with files of my own creation (as in: my own cooked boot.img, and data/system files) but it doesn't seem to get past the G1 boot screen (as in: blank screen.) I've also tried the recovery boot solution however it gives me the same reaction. It leads me to believe the problem lies in my boot file.

ok anyone interested in creating a simple step by step manual? and can someone post the files again please?

[Q] "Damaged SD Card" notification?

What does this notification really mean? I'm running CM7 off an 8G SanDisk. The /sdcard filesystem appears intact, it mounts properly on CM7 and Linux, but this notification won't go away.
fsck on Linux reports no problems.
Might something be confused about partitions? I can't mount /emmc for some reason, CWM can't mount it when I tell it to format it, and USB mode doesn't export it, although it looks like it's trying to; Linux reports a /dev/sde (along with /sdcard at /dev/sdd), but it can't be used:
Code:
# fsck /dev/sde
e2fsck: No medium found while trying to open /dev/sde
Any ideas?
Thanks!
Dennis

Fixed it!
To recap, I'm running CM7 from SD. I was getting a "Damaged SD Card" notification, and my /emmc vanished, and it wouldn't export via USB ("No media present" was the error reported by Linux, although /dev/sde was created), and CWM couldn't format it for me (why not?).
Both were apparently from the same cause. I repaired mmcblk0p8, and now my /emmc is back and the Damaged notification is gone.
So, if you're getting that notification, it may not be about your SD card!
Details: I couldn't use dd from Linux, but I could dd if=...blk0p8 within Terminal Emulator. My busybox doesn't have mkfs.vfat, so I used dd to copy /boot onto the partition; this gives it a (small but sane) filesystem. I rebooted to get /emmc mounted properly (check fstab.vold for the gory details), connected the cable to my Linux PC, checked that the expected contents were on /dev/sde, unmounted it (command line, not via GUI) and ran sudo mkfs.vfat -I -n MyNookColor /dev/sde from the Linux command line. All is now well.

i hv the same issue but since i'm a noob at nook color and i dont knw anything abt linux... i hv no clue what your are talking about...
it would be a gr8 help to me and others who are not well versed with linux, if you could tell me exactly what did u do to fix this problem.
please help me with this issue.
ty
sd

stavan_d said:
i hv the same issue but since i'm a noob at nook color and i dont knw anything abt linux... i hv no clue what your are talking about...
it would be a gr8 help to me and others who are not well versed with linux, if you could tell me exactly what did u do to fix this problem.
Click to expand...
Click to collapse
Android is just as much a Linux system as Ubuntu or Fedora.
This applies if and only if Settings/Storage claims that you have no /emmc or /mnt/emmc, and if you've installed CM7 to emmc. Read the headers carefully.
Start Terminal Emulator.
In this window, type su. The prompt changes to #.
Type df.
If there's a listing for /mnt/emmc or just /emmc, try something else; this isn't for you.
We're going to reconstruct /emmc by copying /boot onto it. THIS WILL ERASE /emmc!!!
Type VERY CAREFULLY:
dd if=/dev/block/mmcblk0p1 of=/dev/block/mmcblk0p8
That's blk zero pee one and blk zero pee eight.
This will grind away for quite some time.
When it's done, reboot.
If you still get the notification, you have some other problem.
You now have a tiny /emmc instead of the 5G partition that should be there. Plug the cable into your PC, enable USB mounting, and verify that one of the volumes looks like a boot partition. If you run a Linux PC, check the device name (mine was /dev/sde, yours is probably different), unmount it, and do the mkfs I showed before.
If you run Windoze, tell it you're done with the /boot drive (like you would do with a thumb drive), and format that device (E:, F:, whichever it was) by (IIRC) right-clicking on it in an Explorer window and selecting Format. Again, SELECTING THE WRONG DEVICE WILL SCREW YOU UP. I am not responsible.
If you're not sure about ANY of these steps, please get expert local help.
Good luck!
Sent from my NookColor using XDA Premium App

i m booting cm7 from the sd card... and settings/storage/additional storage/mnt/emmc Unavailable...
so how do i fix this...
also when i plug NC in boot OS it shows 2 partitions, 1.undefined and 2. 4.98gb... instead of 5gb single partition originally present...

[Q] e2fsck on boot time for fail-proofing SD Card?

I spent more than eight hours to set up HD2 mount /data to sd-ext; but I found that LogCat keeps saying that the error EROFS(Read-only file system) has occurred. After that I went to CWM Recovery, ran e2fsck -yfv /dev/block/mmcblk0p2 and rebooted. It started working again from then; so maybe putting e2fsck command on boot-time script might be useful for failproofing the SD card.
I am using Windows; and I somehow the message cannot find java keeps occurring and I can't use the kitchen. So anybody can help?

you must use e2fsck in order to check the EXT partition before mounting, esp if you are using it for DATA.
also, if you try to mount a bad partition it won't mount as r/w, instead it will mount as r/o (read only). that's why you were having the read-only issue.
regarding java, you need to install JDK. if you have a x64 system, you need both x86 and x64 variants.
hope this helps

blastsound said:
I spent more than eight hours to set up HD2 mount /data to sd-ext; but I found that LogCat keeps saying that the error EROFS(Read-only file system) has occurred. After that I went to CWM Recovery, ran e2fsck -yfv /dev/block/mmcblk0p2 and rebooted. It started working again from then; so maybe putting e2fsck command on boot-time script might be useful for failproofing the SD card.
I am using Windows; and I somehow the message cannot find java keeps occurring and I can't use the kitchen. So anybody can help?
Click to expand...
Click to collapse
How are you mounting /data to EXT? If you are using my method, I have included a accept that scans at boot and then mounts if the partition is clean. Mounted partitions can't be scanned, they have to be unmounted before scanning.
Swyped from my HTC HD2 using XDA Premium

[Tutorial/HOWTO] Convert Your External SD Card from FAT/exFAT to EXT4! (3 ways!)

Hello guys.
I was looking for a similar guide to link to my friend but didn't find anything, so I decided to write my own.
Personally I didn't find any good guide regarding partitioning from android itself, so I think it's also more unique guide because you can easily make your own partition layout without using PC at all.
Why I should use EXT4 instead of FAT/exFAT?
1. We're running Android, Android is based on Linux. EXT4 is native linux-proposed filesystem, while FAT/exFAT is not.
2. All our internal partitions (/efs /data /system /cache /preload) use ext4, natively.
3. CM has poor exfat support, while fat32 is not recommended for big file systems (over 2 GB) because it doesn't work well with them, thus microsoft implemented exfat.
4. EXT4 has better stability and performance, especially on Android devices, compared to exfat and fat.
When you should not use ext4 over fat/exfat?
- When you for whatever reason use your external sd card in windows environment physically. Android works in MTP mode, you'll use your ext4 external sd card the same way as you use internal one under windows. But if you for whatever reason puts your external sd card f.e. in usb adapter connected with windows then it won't work. So yeah, if you keep your external sd card in your phone then you're fine.
Expert Way (Requires fdisk/mke2fs utilities (busybox), works always):
1. Launch any terminal from Android environment (f.e. Android Terminal Emulator or adb shell through PC)
2. Make sure you have root (su command)
3. Make sure you have all required utilities. Type fdisk --help and mke2fs --help, both commands should print usage. If you get "command not found" then you don't have required utilities. Either install Busybox or CM-Based ROM with native busybox support (tested on ArchiDroid 2.X)
4. Unmount your external sd card (umount /storage/sdcard1)
5. Launch fdisk partitioning program on your external sd card (fdisk /dev/block/mmcblk1)
6. Destroy partition table (o), create new partition , make sure it's primary (p) and first one (1).
7. You can check if you're satisfied with your partition layout (p). When you're done exit and save changes (w)
8. Create ext4 filesystem on your partition (mke2fs -t ext4 /dev/block/mmcblk1p1)
9. Reboot
Android should automatically detect and mount external sd card in ext4 after reboot.
Here you can find a short movie which shows going through expert way recorded by me
Intermediate Way (Requires USB Adapter and some patience, should work like a charm):
1. You'd need USB Adapter or any device which can read micro sd cards on PC
2. Open any linux-supported partitioning program (f.e. partition magic, gparted, parted), it needs to support ext4.
3. Delete all partitions from your external SD Card (typically, one fat/exfat) and create one ext4 partition.
4. In case you'd also want hardswap create 2 partitions, one primary ext4 one and second primary swap one.
Newbie Way (Requires PhilZ Touch Recovery, may not work):
1. Launch PhilZ Touch Recovery
2. Select "Mounts & Storage" => "format /external_sd"
3. Select "ext4" as a filesystem
4. Please note that it can take some time. This way you should get running ext4 filesystem, but personally I didn't test this method, as I prefer more advanced ones .
This guide is more or less universal but I'm using sgs3 external sd card paths so I want to make sure nobody bricks other phones . Personally I suggest using expert way, as it's probably the easiest one.
Hit thanks if it helped, I hope it did .

@JustArchi thanks for the tutorial. Now for the sake of sdcard wearing. I would like to disable Journaling. How do you do that?
EDIT: also i noticed after formatting the externalsd card there is 3 GB occupied by nothing (?) This is normal?

cba1986 said:
@JustArchi thanks for the tutorial. Now for the sake of sdcard wearing. I would like to disable Journaling. How do you do that?
EDIT: also i noticed after formatting the externalsd card there is 3 GB occupied by nothing (?) This is normal?
Click to expand...
Click to collapse
tune2fs -O ^has_journal /dev/block/mmcblk1p1 should do the trick. You can put it in init.d if needed.
Also no, you should get full size of your sdcard. Are you sure that you've firstly destroyed partition table (o) and then created new full-size partition , as showed in the video?
You can use fdisk also to get information about your external sd card and find why is it smaller than it should be.

HI, My 64gb is two partitioned one hardswap and other primary.
Will I lose data on both partitions if I delete partition and format to EXT4?

golti said:
HI, My 64gb is two partitioned one hardswap and other primary.
Will I lose data on both partitions if I delete partition and format to EXT4?
Click to expand...
Click to collapse
You will lose data contained in the partition you are formatting. If you leave the other partitions untouched, you won't lose their data.

golti said:
HI, My 64gb is two partitioned one hardswap and other primary.
Will I lose data on both partitions if I delete partition and format to EXT4?
Click to expand...
Click to collapse
Just don't use (o), as it will destroy everything. Use an option to delete selected partitions (d, if I remember correctly) and create them through n.

System Data
Hi, thanks for te help, but now a have a 1 gb lost by system data or 0.8gb if i disable the journaling, that is right??? Thanks

vazio said:
Hi, thanks for te help, but now a have a 1 gb lost by system data or 0.8gb if i disable the journaling, that is right??? Thanks
Click to expand...
Click to collapse
It depends on your rom and also if you created ext4 properly. I've formatted my 2 GB SD Card to EXT4 and I got 1,80 GB free (yes with journaling). This is because 5%-10% is reserved for "super blocks". Read more -> http://en.wikipedia.org/wiki/Ext4

problem using expert method
Hi Guys,
I am new fairly new to rooting and using terminal emulators.
I have a rooted samsung galaxy note 2 with superSU, busybox and shell terminal emulator. I verified fdisk and mke2fs
(fdisk --help and mke2fs --help) but then when I tried the command
"umount /storage/extSdCard"
I get the error message "Operation not permitted"
Can anyone tell me why this might be?
Thanks
/storage/extSdCard is the path to the external sdcard on my device.

Hottot2 said:
Hi Guys,
I am new fairly new to rooting and using terminal emulators.
I have a rooted samsung galaxy note 2 with superSU, busybox and shell terminal emulator. I verified fdisk and mke2fs
(fdisk --help and mke2fs --help) but then when I tried the command
"umount /storage/extSdCard"
I get the error message "Operation not permitted"
Can anyone tell me why this might be?
Thanks
/storage/extSdCard is the path to the external sdcard on my device.
Click to expand...
Click to collapse
Did you login as root before? (su)

JustArchi said:
Did you login as root before? (su)
Click to expand...
Click to collapse
I did not.
However, I did try again and got the sane result. I used these commands in shell terminal emulator:
su -
mount
umount /storage/extSdCard
result: "Failed: Operation not permitted"
I have verified root with root checker...and after typing the command "su -" I was prompted by supersu to "allow"
I believe this issue will likely be something simple that I am not aware of.
I have tried this on my galaxy note 2 and my tab3 8.0 with the same results.
I really appreciate any help offered.

Hottot2 said:
I did not.
However, I did try again and got the sane result. I used these commands in shell terminal emulator:
su -
mount
umount /storage/extSdCard
result: "Failed: Operation not permitted"
I have verified root with root checker...and after typing the command "su -" I was prompted by supersu to "allow"
I believe this issue will likely be something simple that I am not aware of.
I have tried this on my galaxy note 2 and my tab3 8.0 with the same results.
I really appreciate any help offered.
Click to expand...
Click to collapse
Try to execute su -c "umount /storage/extSdCard"
It worked flawlessly in my case.

Thanks Archi. I was wandering around looking for a solution to the problem with my sd(I'm nooo0b if it goes about Linux/Android ). My Archidroid 2.3.3 did not recognized/mount my external card, so after following your instructions (using the terminal in android) now I can enjoy my 64gb sd card.. Great job!

JustArchi said:
Try to execute su -c "umount /storage/extSdCard"
It worked flawlessly in my case.
Click to expand...
Click to collapse
Ok. That worked. Thanks.
I then tried (su -c "fdisk /dev/block/mmcblk1")
Then...press m for help...or pressing "o" gets me a syntax error.
I have attached a screenshot.
Thanks again
Ryan

Hottot2 said:
Ok. That worked. Thanks.
I then tried (su -c "fdisk /dev/block/mmcblk1")
Then...press m for help...or pressing "o" gets me a syntax error.
I have attached a screenshot.
Thanks again
Ryan
Click to expand...
Click to collapse
Okay, you're user, not root. This is a weird android shell, that's why.
Try to use "su -i" to get root shell, then use fdisk (without su).

JustArchi said:
Okay, you're user, not root. This is a weird android shell, that's why.
Try to use "su -i" to get root shell, then use fdisk (without su).
Click to expand...
Click to collapse
Still didnt work. After typing "su -I" the next line still says "[email protected]:/$"
I was thinking I could try a reinstall of shell terminal emulator...or perhaps you could recommend a different one to use.
I will try again later tonight.
Thanks
Ryan

Hottot2 said:
Still didnt work. After typing "su -I" the next line still says "[email protected]:/$"
I was thinking I could try a reinstall of shell terminal emulator...or perhaps you could recommend a different one to use.
I will try again later tonight.
Thanks
Ryan
Click to expand...
Click to collapse
Try android terminal emulator, you must gain root shell. Typically "su" command does that, "su -l" should as well.

JustArchi said:
Try android terminal emulator, you must gain root shell. Typically "su" command does that, "su -l" should as well.
Click to expand...
Click to collapse
Alright...typed su and gained root....got through ttothe last step.
I typed "mke2fs -t ext4 /dev/block/mmcblk1p1"
and the result was: "mke2fs: invalid option -- t"
I have trying to read about mke2fs and the -t option but no luck so far.
Thanks
Ryan

Hello Archi and thanx for the tutorial
I followed all the steps, done it to the end, but after reboot I couldn't make any folder on SD card.
Card is recognized, formated as EXT4, but for some reason there is no way to put anything to it
Tried again with gparted, ended with same result.
Tried to change ownership, but that also didn't work out...
Now i reverted card to fat32...
Any idea what could be wrong?
btw, using NeatROM 4.4.2 with boeffla kernel and Philz 6.00.8
thanx in advance

Tom-Tom07 said:
Hello Archi and thanx for the tutorial
I followed all the steps, done it to the end, but after reboot I couldn't make any folder on SD card.
Card is recognized, formated as EXT4, but for some reason there is no way to put anything to it
Tried again with gparted, ended with same result.
Tried to change ownership, but that also didn't work out...
Now i reverted card to fat32...
Any idea what could be wrong?
btw, using NeatROM 4.4.2 with boeffla kernel and Philz 6.00.8
thanx in advance
Click to expand...
Click to collapse
Ext4 support is broken in your rom.
Hottot2 said:
Alright...typed su and gained root....got through ttothe last step.
I typed "mke2fs -t ext4 /dev/block/mmcblk1p1"
and the result was: "mke2fs: invalid option -- t"
I have trying to read about mke2fs and the -t option but no luck so far.
Thanks
Ryan
Click to expand...
Click to collapse
Your rom doesn't support mke2fs properly.

Mount EXT4 MicroSD Card

I've given up on reformatting the internal memory as EXT4 (my last post). However now, I want to mount an external SD card that is EXT4 (or any file format that has UNIX permissions). I can't get my device to mount the card, it says the filesystem is unsupported. Now, that's bull**** since Android has built in support for EXT. After searching threads here on XDA and Google, and even purchasing EzyMount as recommended, I can't get it to mount. I've tried BusyBox and mount commands (as root), with various errors such as "mount operation not supported on transport endpoint". I'm at my wit's end by now, trying to get some filesystem which has support for symlinks and UNIX permissions... any ideas?

kcattakcaz said:
I've given up on reformatting the internal memory as EXT4 (my last post). However now, I want to mount an external SD card that is EXT4 (or any file format that has UNIX permissions). I can't get my device to mount the card, it says the filesystem is unsupported. Now, that's bull**** since Android has built in support for EXT. After searching threads here on XDA and Google, and even purchasing EzyMount as recommended, I can't get it to mount. I've tried BusyBox and mount commands (as root), with various errors such as "mount operation not supported on transport endpoint". I'm at my wit's end by now, trying to get some filesystem which has support for symlinks and UNIX permissions... any ideas?
Click to expand...
Click to collapse
you fully rooted with custom kernel or only with rdlv etc?
First you gotta figure out how to mount this damn thing, gotta be possible.
Then you need to get this done on bootup, either in init.rc or init.d or smth.
You probably just use wrong commands? But I could be wrong, didnt try that yet but would also be interested. Having the file permissions also on SD would be nice, but it could cause trouble with mtp maybe?

zroice said:
you fully rooted with custom kernel or only with rdlv etc?
First you gotta figure out how to mount this damn thing, gotta be possible.
Then you need to get this done on bootup, either in init.rc or init.d or smth.
You probably just use wrong commands? But I could be wrong, didnt try that yet but would also be interested. Having the file permissions also on SD would be nice, but it could cause trouble with mtp maybe?
Click to expand...
Click to collapse
I am rooted, but stock ROM and kernel. MTP is for connecting to a computer? If it is, I don't need that. I have tried
mount -rw -t ext4 /dev/block/mmcblk1p1 /storage/extStorageCard
and variants switching the flags and options.

Interesting... I just typed that command in to make sure I didn't make any typos.... and my phone crashed and rebooted. I typed it again to see if it would cause another crash and it appears to have mounted the card! Whwn I type "df" at the prompt it now shows a 28.6 GB filesystem at that location, which has to be my sd card.
Why, how, I don't know. It works, it's all I can say.