External SD card always mounted as read only

[zygd]

4K android media box with AML812 chip. 2 USB ports, 1 USB OTG port and one SD card slot. Android 4.4.2 (KitKat?)
USB drive connected with FAT system is mounted as read/write device, all SD card I have tested were mounted as read only.
At first I wanted to make firefox to download files to SD card. But firefox had no rights to write to SD.
At second I thought that firefox can't write to SD because new privilages system in KitKat. So I found a solution on the web and have added media_rw entries in
/system/etc/permissions/platform.xml file in WRITE_EXTERNAL_STORAGE section. But it didn't help.
I used SDFix from Playstore - it reported that fix has been applicated already (see above). I doesn't do more than add media_rw entries.
Then I have found out, that SD card is always mounted as read only by default - i tried 3 different SD cards, no success.
I have checked SD card with fsck_msdos and externally on my desktop PC - SD card had no errors.
I tried to remount SD as read/write with mount -o remount,rw device from terminal and it worked but apparently only apps with root privilages can write to SD. Firefox still can't write to SD.
And if I close terminal the SD returns to read only state.
Don't know what to do, where to find the solution.
In vold.fstab there is only one command with dev_mount, and this command doesn't have read/write or read only flags.
There is no fstab.device files on the box, which are common? in KitKat (above android 4.3) so I am not so sure that this is KitKat device.
Please help to unlock SD card write rights.

[gefattern]

Hi zygd

You can try KitKat SDfix App from Playstore.That must help.Try & report


nice Day


gefattern

[zygd]

You can try KitKat SDfix App from Playstore.That must help.Try & report

Used already, it only adds media_rw entries in platform.xml.
I don't think the issue is new KitKat media_rw permission. The SD card is always mounted as read only by default (on restart device and on inserting card).
It is common behaviour when card has some error. But I checked it (fsck_msdos and scandisk on PC). And I checked 2 other cards.
I have found other info, that some devices treat external vfat sdcard always as read only medium. I will try to reformat it to exFat or NTFS.
But it is some idiocy to me - my other android phone doesn't have such issues with any SD cards.

EDIT: formatting to exFAT, NTFS or FAT32 with 32KB chunk size didn't resolve anything (advice from some android forum). My device doesn't recognize exFAT, and the rest give me read only mount point.
I installed Paragon exFat, NTFS app. It can't mount SD correctly at all. It unmounts mounted SD very good though. It can't check and fix SD because /dev/block/mmcblk0p1 is read-only file system.
The same goes for format - Error 0x1e from mkhfs.
When I try to mount SD with Paragon nothing happens (the mount button is still active, and unmount is inactive), and android memory settings show that SD card has been mounted as 803 MB card, not 16 GB card (14,84 GB exact capacity). Paragon can only unmount SD.
Now I see that I can't even format SD card from android memory settings. When I choose format, it unmounts SD card but then nothing happens. There is no format operation going on.
Really I don't have any more idea.

[gefattern]

Hi fygd

i hope you can find a Solution.

nice Day

gefattern

[zygd]

No, wasted many time and didn't find any reliable solution. You need root to write to SD card and You can do this only in apps which are asking for root.
You need to remount SD to rw mode, but it still is not working with any apps.