Page 1 of 2

External SDHC card integration?

PostPosted: February 21st, 2012, 6:35 pm
by Trashcooky
I feel like I am about to say something really stupid and get the siren blast they use on "Qi" when someone gives an obvious but wrong answer.
So here goes, from a Forum newbie, with no doubt a stupid question.

The Scroll Excel is advertised as having 4Gb memory expandable to 32Gb.
I have installed/mounted a mini SDHC 32G card and I can explore this quite easily using "ES file explorer".
I can install apps using "Easy Installer", directly from my mounted/external SDHC card, these are apps which I have sideloaded to it from my PC.
Using the utility "Apps 2 SD" I can move (most) apps from (phone) memory to the (NAND) sd card following their installation.
What I can't seem to do is use my externally/mounted SDHC card as an extension to the (NAND) sd card memory - i.e. taking the system usable storage to the full 32Gb as loosely implied in the Scroll advertising.

Currently my Scroll tells me I have 334Mb available space - Flash memory - (which I assume to be the nand SD card), and I have a device total available space of 669 Mb which I assume to be (phone) internal memory of 335 Mb + 334 Mb internal sd card = 669 Mb.

Following all these assumptions which may be right or wrong - what I want to find out is this:

When the (nand) internal SD card is filled, will additional installation/transfer space automatically become available due to having mounted an external SDHC card?
I don't believe it will because (currently) my system points to the internal SD card location not the external SDHC card location - when moving installed apps to the SD card.
However, is it possible to make the system point to the external SDHC card as well as, or indeed instead of, the internal SD card - and if so - what would need to be done to achieve this?

Preferably without bricking the Scroll - :oops:
I hope I have made my enquiry clear and not too obtuse, be very grateful for any knowledge on this subject.

Re: External SDHC card integration?

PostPosted: February 21st, 2012, 7:09 pm
by suggsy89
The kernel seems okay.....

C:\cygwin\kitchen\excel boot images\boot.img-ramdisk\init.rc
# setup the global environment
export PATH /sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin
export LD_LIBRARY_PATH /vendor/lib:/system/lib
export ANDROID_BOOTLOGO 1
export ANDROID_ROOT /system
export ANDROID_ASSETS /system/app
export ANDROID_DATA /data
export FLASH_STORAGE /mnt/extern_sd
export HOST_STORAGE /mnt/usbhost1
export EXTERNAL_STORAGE /mnt/sdcard
export ASEC_MOUNTPOINT /mnt/asec
export LOOP_MOUNTPOINT /mnt/obb

Is there an option in the app itself to use your external sdcard?
Best thing to do is wait to see if anyone else is experiencing this problem

Re: External SDHC card integration?

PostPosted: February 21st, 2012, 8:26 pm
by Trashcooky
suggsy89 wrote:The kernel seems okay.....

C:\cygwin\kitchen\excel boot images\boot.img-ramdisk\init.rc
# setup the global environment
export PATH /sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin
export LD_LIBRARY_PATH /vendor/lib:/system/lib
export ANDROID_BOOTLOGO 1
export ANDROID_ROOT /system
export ANDROID_ASSETS /system/app
export ANDROID_DATA /data
export FLASH_STORAGE /mnt/extern_sd
export HOST_STORAGE /mnt/usbhost1
export EXTERNAL_STORAGE /mnt/sdcard
export ASEC_MOUNTPOINT /mnt/asec
export LOOP_MOUNTPOINT /mnt/obb

Is there an option in the app itself to use your external sdcard?
Best thing to do is wait to see if anyone else is experiencing this problem


Hi Suggsy89,

I have looked for an option to change the location on shifting to SD but I can't find one in the app/utility "Apps 2 SD"
I don't know if there are other utility apps that can do this?

Thanks for your help but I'm afraid this is way over my head (at the moment - trying to learn)
I wasn't sure if it was possible to edit the system in order to make it think the external SD card is the internal SD card simply by pointing the system to it by renaming the folder.

At the moment the internal SD card is located here: "/mnt/sdcard/"
The external SD card is located here: "/mnt/extern_sd"
Is it possible to simply rename "/mnt/extern_sd" to "/mnt/sdcard/" and everything to still work ?
If so and the system still works then I will truly expand my working SD storage to 32Gb at the loss of the internal 4Gb nand SD card.

Re: External SDHC card integration?

PostPosted: February 21st, 2012, 8:55 pm
by suggsy89
No sir, not possible at the moment without the risk of bricking the Excel.
We do no currently have a backup option such as reflashing the OS.

It seems to me the app2sd app is using /mnt/sdcard as the location for "external" apps

Like you said this would need to be changed, at kernel level.... the boot.img file

I as well as Mitre and Charlie are working on an update, i do not own the Excel, so doing this is probably going to be slow, unless Storage Options release an update. ;)

Re: External SDHC card integration?

PostPosted: February 23rd, 2012, 2:30 am
by blueeagle69
If it wasn't for GltoSD and my new fave DirectoryBind I would be stuffed.
But it would be amazing if the external storage was simply an extension of the sd card, without using virtual mounting.

Re: External SDHC card integration?

PostPosted: January 11th, 2013, 1:03 pm
by andydroid2012
I fear the problem is deeper.
I have usbhost as a mountable device of SDHC cards on my noname tablet running android v 4.0.3 and also
extsd as a mountable microSD slot and
sdcard as the internal memory

I can see

mnt/extsd
mnt/usbhost
mnt/sdcard

I am only able to write to the sdcard using a Basic language program opeing data files.

Why have any external device ? I just do not know !

The answer appears to be buried in android OS and will presumably be announced one day.

Re: External SDHC card integration?

PostPosted: January 11th, 2013, 1:17 pm
by blueeagle69
andydroid2012 wrote:I fear the problem is deeper.
I have usbhost as a mountable device of SDHC cards on my noname tablet running android v 4.0.3 and also
extsd as a mountable microSD slot and
sdcard as the internal memory

I can see

mnt/extsd
mnt/usbhost
mnt/sdcard

I am only able to write to the sdcard using a Basic language program opeing data files.

Why have any external device ? I just do not know !

The answer appears to be buried in android OS and will presumably be announced one day.

Hi.
Are you saying that you cannot write to the external card?
If this is the case then give this a try.
viewtopic.php?p=229#p229

Sent from my GT-I9300 using Tapatalk 2

Re: External SDHC card integration?

PostPosted: January 11th, 2013, 6:24 pm
by andydroid2012
blueeagle69,
exactly that. - My hardware is a tablet and the app is a version of Atari Basic from the '80s re-written for android/java.
It can read/write files in the internal memory sdcard but fails when accessing any external media. The developer says its a bug in android, or he has not solved the method required....
Searching the web shows hundreds of people add external SDHC memory chips thinking its an expedient way to add more apps but it turns out that most apps can only exist and function in the internal [sdcard] world.
The very name [sdcard] implies it is SDHC memory but its on the motherboard and I bet its on an internal memory bus.
Attempting to read or write even an existing file in the external [ via USB on-the-go cable, or extsd the microSD slot in the side of the tablet] produces an error saying cannot open the file.
This is with android 4.0.3 and the latest version of X11-Basic

Re: External SDHC card integration?

PostPosted: January 20th, 2013, 3:48 pm
by blueeagle69
andydroid2012 wrote:blueeagle69,
exactly that. - My hardware is a tablet and the app is a version of Atari Basic from the '80s re-written for android/java.
It can read/write files in the internal memory sdcard but fails when accessing any external media. The developer says its a bug in android, or he has not solved the method required....
Searching the web shows hundreds of people add external SDHC memory chips thinking its an expedient way to add more apps but it turns out that most apps can only exist and function in the internal [sdcard] world.
The very name [sdcard] implies it is SDHC memory but its on the motherboard and I bet its on an internal memory bus.
Attempting to read or write even an existing file in the external [ via USB on-the-go cable, or extsd the microSD slot in the side of the tablet] produces an error saying cannot open the file.
This is with android 4.0.3 and the latest version of X11-Basic

Sorry looks like the link was wrong.
Take a look at this, and see if this is your issue.
viewtopic.php?t=2202
Although if you only have one app with the issue then it may not be the case.

Sent from my Nexus 7 using Tapatalk HD

Re: External SDHC card integration?

PostPosted: March 1st, 2013, 11:56 pm
by andydroid2012
Sorry it took a while to get back here.

This is the solution to writing to an external SD card.

From the get-go your card can NOT be written to. I am talking about all cards other than the inboard ramchip used by the OS and the remainder, about 1.2Gb on a 4gb system for apps to read-write.

You can copy to and from the external media USBSD or EXTSD or whatever its named on your android, but neither programs nor apps can WRITE to it. Yes COPY writes, but that is a file maintenance feature different than programs WRITE_ACCESS

The reason is there is a file called platform.xml which is read-only says which media is programmably writable,
now, this can be gotten around if you really want an app to write to external media, maybe an app you wrote by yourself. This involves mildly dangerous editing, so if you are wary, leave now.

You need an editor like ES File Explorer and it can edit and modify a read-only file. When done the file remains read-write but android OS seems happy.

If you want to proceed then go here to read the full details
http://www.basic4ppc.com/forum/basic4an ... post151701