[yocto] Mounting USB drives on a "read-only-rootfs" based system

[Jeffrey D Boyer]

Sorry, /media is not a symlink and there is no /run/media link or directory present on my running system.  When I insert an SD card, for example, I get a bit of text on the debug serial port that a card has been detected, but I don't see a mount point anywhere after that.

	root at mySys:/# mmc1: new high speed SDHC card at address 1234
	mmcblk1: mmc1:1234 SA04G 3.63 GiB
	 mmcblk1: p1

It should be noted that if I exclude the " read-only-rootfs" option in the bb script, a normal read/write kernel image is produced and the action of inserting an SD card under those conditions will automatically produce a mount point at /media/mmcblk1p1

FYI, I'm running 3.14 kernel.  Is this a job for aufs?  If so, how would I go about configuring it?


-----Original Message-----
From: Mike Looijmans [mailto:mike.looijmans at topic.nl] 
Sent: Tuesday, June 14, 2016 9:18 AM
To: Christopher Larson <clarson at kergoth.com>; Jeffrey D Boyer <Jeffrey.D.Boyer at jci.com>
Cc: yocto at yoctoproject.org
Subject: Re: [yocto] Mounting USB drives on a "read-only-rootfs" based system

Yup, even mdev based images do that with current OE.

I'd expect "/media" to symlink to "run/media" on most devices (regardless whether the rootfs is read-only or not). Check if that's the case on your system.

On 14-06-16 00:01, Christopher Larson wrote:
> Afaik usb storage is already automounted by udev on /run/media/, so 
> there's no need to use /media for that purpose.
>
> On Mon, Jun 13, 2016 at 2:22 PM, Jeffrey D Boyer 
> <Jeffrey.D.Boyer at jci.com <mailto:Jeffrey.D.Boyer at jci.com>> wrote:
>
>     Hello,____
>
>     __ __
>
>     New to the list here, so I’m sorry if this question has been asked before,
>     but I couldn’t find a direct answer to it. ____
>
>     __ __
>
>     I have a yocto image that was built using the following bb script line:
>     IMAGE_FEATURES += " read-only-rootfs". ____
>
>     __ __
>
>     As this image eventually resides on a static flash device, it must be
>     read-only.  However, the system hardware supports removable media (SD card
>     and USB drives), and I’d like to be able to mount and write to those
>     removable drives / partitions for data logging purposes.  What needs to be
>     done in order to make the /media directory auto-mountable when a
>     “read-only” image is specified by the build script?____
>
>     __ __
>
>     Thanks.____
>
>     __ __
>
>
>     --
>     

Kind regards,

Mike Looijmans
System Expert

TOPIC Embedded Products
Eindhovenseweg 32-C, NL-5683 KH Best
Postbus 440, NL-5680 AK Best
Telefoon: +31 (0) 499 33 69 79
E-mail: mike.looijmans at topicproducts.com
Website: www.topicproducts.com

Please consider the environment before printing this e-mail





_______________________________________________
>     yocto mailing list
>     yocto at yoctoproject.org <mailto:yocto at yoctoproject.org>
>     https://lists.yoctoproject.org/listinfo/yocto
>
>
>
>
> --
> Christopher Larson
> clarson at kergoth dot com
> Founder - BitBake, OpenEmbedded, OpenZaurus Maintainer - Tslib Senior 
> Software Engineer, Mentor Graphics
>
>