I created a zeroed file with dd and attempted to mount it with:
mount -o loop /sdcard/test.img /data/test
and
losetup /dev/block/loop0 /sdcard/test.img
However, no loopback devices are displayed when I invoke mount. Can anyone clue me in? Feel like i'm missing something basic. By the way, I am running these commands from Saurik's busybox with the losetup /dev/block/loop fix.
p.s. I'd ask on the G1 hackers mailing list, but it's gone a bit bonkers in the past few days.
I'm not sure, but doesn't the image file you're trying to mount have to contain an actual file system?
Yea, I subsequently created a filesystem for it with mke2fs (which is mysteriously missing from busybox for android?). Still no go. Same when I tried to mount other partition-in-a-files like the module.cramfs or recovery.img
If I try to losetup the loop device then mount that, it returns error:
mount: mounting /dev/block/loop0 on /data/test failed: No such device
If I try to mount directly with -o loop, it returns:
mount: cannot setup loop device: No such file or directory
And yet Saurik seems to have been able to loop mount fine. Perhaps it is because I am testing on the qemu instead of hardware?
That might be it. You might try busybox's mount also.
But yeah, It definitely does work on the phone at least.
I've been trying to figure out how to load debian on the emulator, but I can't get the ext2 image mounted. I had to recompile the kernel first so support loadable modules, but even after that, it would not work (can't remember the specific error). Has anyone gotten an ext2 file system mounted on the emulator successfully?
The reason I'm doing this is so I can do native compiles, without actually having to do it on the phone. It has advantages in that I can crank up the clock speed and the RAM.
So I was able to mount loopback just fine on the actual hardware, but i'm having trouble getting it to run from the init.rc file. This is what i'm typing at the shell (it works):
(after insmod ext2.ko)
mount -o loop,noatime,nodiratime,nosuid,nodev -t ext2 /sdcard/loopy/app.img /data/app
It works fine and i'm able to install and run apks from the sdcard (/dev/block/loop2 on /data/app type ext2). Of course this is no good unless it can be mounted before the launcher starts (or it won't see any of our apks). The syntax for init mounting is different from sh, so I tried this (this is in /data/init.rc btw):
on userdata
#mount loopback file from sdcard
insmod /system/modules/2.6.25-01843-gfea26b0/kernel/fs/ext2/ext2.ko
mount ext2 /sdcard/loopy/app.img /data/app noatime nodiratime nosuid nodev loop
I know the script is being run since the ext2.ko module is getting installed. But the mount command isn't being executed. Can anyone shine a light on this? I'm not very familiar with the init daemon.
jashsu said:
So I was able to mount loopback just fine on the actual hardware, but i'm having trouble getting it to run from the init.rc file. This is what i'm typing at the shell (it works):
(after insmod ext2.ko)
mount -o loop,noatime,nodiratime,nosuid,nodev -t ext2 /sdcard/loopy/app.img /data/app
It works fine and i'm able to install and run apks from the sdcard (/dev/block/loop2 on /data/app type ext2). Of course this is no good unless it can be mounted before the launcher starts (or it won't see any of our apks). The syntax for init mounting is different from sh, so I tried this (this is in /data/init.rc btw):
on userdata
#mount loopback file from sdcard
insmod /system/modules/2.6.25-01843-gfea26b0/kernel/fs/ext2/ext2.ko
mount ext2 /sdcard/loopy/app.img /data/app noatime nodiratime nosuid nodev loop
I know the script is being run since the ext2.ko module is getting installed. But the mount command isn't being executed. Can anyone shine a light on this? I'm not very familiar with the init daemon.
Click to expand...
Click to collapse
Try
mount ext2 [email protected]/sdcard/loop/app.img /data/app noatime nodiratime nosuid nodev
JesusFreke said:
Try
mount ext2 [email protected]/sdcard/loop/app.img /data/app noatime nodiratime nosuid nodev
Click to expand...
Click to collapse
Tried that one earlier too. No love.
jashsu said:
Tried that one earlier too. No love.
Click to expand...
Click to collapse
I betcha the sdcard hasn't been mounted yet.
Is there anything in dmesg that looks relevant? Or maybe logcat?
Try temporarily moving the image file to /data, and see if you can get it to mount. That should verify that it has something to do with it being on the sdcard
JesusFreke said:
I betcha the sdcard hasn't been mounted yet.
Is there anything in dmesg that looks relevant? Or maybe logcat?
Click to expand...
Click to collapse
Agh! You're right. The mount daemon runs at line 192, in the services section. Long after the /data/init.rc is parsed.
service mountd /system/bin/mountd
socket mountd stream 0660 root mount
Any way around this short of manually mounting the sdcard in the /data/init.rc?
Edit: dmesg bingo:
<3>[ 1.920368] init: unable to mount [email protected]/sdcard/loopy/app.img to /data/app
as ext2
<6>[ 1.921498] yaffs: dev is 32505860 name is "mtdblock4"
<6>[ 1.922016] yaffs: passed flags ""
<4>[ 1.922322] yaffs: Attempting MTD mount on 31.4, "mtdblock4"
<4>[ 1.927204] yaffs: restored from checkpoint
<4>[ 1.927845] yaffs_read_super: isCheckpointed 1
<3>[ 1.960002] init: unable to mount /system/xbin.cramfs to /system/xbin as c
ramfs
<3>[ 1.965221] init: service 'console' requires console
<4>[ 2.161895] mmc_sd_init_card: Delay 250 ms
<4>[ 2.522535] mmc1: host does not support reading read-only switch. assuming
write-enable.
<6>[ 2.523359] mmc1: new SDHC card at address cd4e
On a side note, it looks like the mount action for xbin.cramfs in the main init.rc is failing because it's redundant with an earlier mount in /system/init.rc. I'm guessing this is a vestige of development on cramfs loopback mounting (mentioned here by Saurik).
6) at Jesus Freke's suggestion, setup /system/xbin (and later /system/modules) to mount from a compressed image
Click to expand...
Click to collapse
Yeah, I had left in an extra mount for xbin.cramfs in the base init.rc. I believe that's fixed in v1.3. I'll check again and make sure
So I gather the reason for wanting to mount a loopback device is to be able to create an ext2 fs as a file on the sdcard fat fs instead of creating 2 separate parittions on the sdcard , one for fat and one for ext2?
If this can be done, this would be a much better solution for getting apps to run on the sdcard than the previous hack which requires creating an ext2 partition on the sdcard.
Yeah that was what I was looking into. However as noted above, the I couldn't mount the image on the sdcard because the point at which /data/init.rc gets parsed occurs before the sdcard service starts up. The partition method doesn't have this problem because it creates a node for paritition #2 in the init.rc
jashsu said:
Yeah that was what I was looking into. However as noted above, the I couldn't mount the image on the sdcard because the point at which /data/init.rc gets parsed occurs before the sdcard service starts up. The partition method doesn't have this problem because it creates a node for paritition #2 in the init.rc
Click to expand...
Click to collapse
so u can't mount the sdcard in /data/init.rc?
dwang said:
so u can't mount the sdcard in /data/init.rc?
Click to expand...
Click to collapse
Not sure, I didn't try mounting partition #1. You could give it a shot by using mknod in /data/init.rc like the parted sdcard method. The sdcard service might not like that the card has already been mounted though.
There are two major reasons I abandoned this concept. The first is I didn't want to figure out how to get permission to mount /sdcard (since / is ro). The second is that making the sdcard available as a usb mass storage device makes it exclusively unaccessible from Android. I suppose that might not be so bad if you are only offloading /data/app, as long as you don't try to execute any new apps while your mass storage connection is going. It's non-ideal.
jashsu said:
Not sure, I didn't try mounting partition #1. You could give it a shot by using mknod in /data/init.rc like the parted sdcard method. The sdcard service might not like that the card has already been mounted though.
There are two major reasons I abandoned this concept. The first is I didn't want to figure out how to get permission to mount /sdcard (since / is ro). The second is that making the sdcard available as a usb mass storage device makes it exclusively unaccessible from Android. I suppose that might not be so bad if you are only offloading /data/app, as long as you don't try to execute any new apps while your mass storage connection is going. It's non-ideal.
Click to expand...
Click to collapse
I don't think the 2nd reason is that big of a deal. If google is planning on implementing the file based method for apps on the sdcard, they could just block access to apps when the sdcard is mounted to a pc. Its a lot better than the alternative of having to create a 2nd ext2 partition on the sdcard. Of course google should have really solved this issue before the g1 came out.
Anyways, I don't see /data/init.rc on my jf rc 1.2 g1. I only see /init.rc and /system/init.rc. Is /data/init.rc something that you created just for the purpose of mounting the file.
dwang said:
I don't think the 2nd reason is that big of a deal. If google is planning on implementing the file based method for apps on the sdcard, they could just block access to apps when the sdcard is mounted to a pc. Its a lot better than the alternative of having to create a 2nd ext2 partition on the sdcard. Of course google should have really solved this issue before the g1 came out.
Anyways, I don't see /data/init.rc on my jf rc 1.2 g1. I only see /init.rc and /system/init.rc. Is /data/init.rc something that you created just for the purpose of mounting the file.
Click to expand...
Click to collapse
Yeah it's referenced in /init.rc Easier to use since unlike /system/init.rc, it's not in a ro folder. You could use /system/init.rc too. Either way really.
jashsu said:
Yeah it's referenced in /init.rc Easier to use since unlike /system/init.rc, it's not in a ro folder. You could use /system/init.rc too. Either way really.
Click to expand...
Click to collapse
Ok.. I'll probably just stick with partitioning the sdcard into fat and ext2. Its working well for me and there really isn't a whole lot of advantages having the ext2 as a file on the fat partition.
I have 41 apps installed on the sdcard now (including some huge games like bonzai blast and brain genius deluxe) and I still have 59 megs of free internal storage. I think everybody that has a rooted g1 should put apps to the sdcard.
Anyone tried this, and any reason it wouldn't give a speed boost?
P
Just to inform you guys, swap doesn't support yaffs2 ;-)
Ah yes, I see. I wonder if you could create a ext3 img on /data and mount that, then create a swap file on there. Wonder if it'd be worth it...
P
My captivate is already rooted, i use the Astro app to edit files and now im trying to edit the /system/etc/gps.conf, but when i try to save...does not save...i notice this file is read only rights. How can i edit that and save it???
to mount /system as read write, you need to be rooted (obviously) and open up an adb shell.
mount -o rw /dev/block/stl9 /system
depending on what kernel you're running and what filesystem /system is mounted as you *may* need to specify the filesystem ("-t vfat" for rfs, "-t ext4" for voodoo) but I've never had to before.
I am using 2.6.32.32 - VFPv3_FP - Gtab/Zpad updated 03-07-2011 Kernel on Vegan 5.1
and I have found many threads on NTFS support for mounting like
http://forum.xda-developers.com/showthread.php?t=914822 and http://forum.xda-developers.com/show...5&postcount=27
but I have found nothing on NTFS writeable support; the newest kernel, which I am on, states:
-add NTFS (w./ write support (proceed with caution if writing!)),CIFS,FUSE,TUN (kernel modules; pull the desired module from lib-2632.29.tar.gz and place in to /system/lib/modules/2.6.32.31-cyanogenmod/ and use insmod to insert) and EXT4 (in-built)
so how do I go about making my NTFS drive writeable
I can mount and unmount it but it is readable only, even tried mounting it mount -o rw and it then will show up as r/w in root explorer but when I try to copy and past something onto the drive nothing copies so it is showing as being writeable but is not apparently writeable, I must be missing something.
Thanks
This is a very annoying issue but I have not found any thread about it.
I'm trying to upgrade my external/removable sdcard for an android 6 device.
The new sdcard gets mounted to /mnt/media_rw/XXXX-XXXX (i.e. not 0123-4567), so no app works as files can't be found.
The linux way (ln) wont work. Simply creating /mnt/media/0123-4567 causes bad bootloop on my device. This suggests that FolderMount app or Magisk modules such as fbind are a bad idea. selinux is enforcing.
It appears that Android assigns different mount points are to different sdcards and the first sdcard always gets 0123-4567. It that's right, Android probably stores sdcards' identifiers so as to know which mount point to use at boot time. So, deleting the identifiers database would probably mean that the next card inserted would get 0123-4567 as mount point.
I have looked at the data of com.android.externalstorage, but there is nothing there. I don't see other obvious candidate apps.
Where is this ext sdcard data stored?
I was wrong. Android sets mount points matching sdcard uuid
How to change vfat partition UUID?
How do I change the UUID of a vfat partition? For ext2 / ext3 / ext4, this is done with a simple: tune2fs -U <new-uuid> /dev/<partition> Is there a similar command for vfat partitions?
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