Significance of /media/linaro/00BC-614E


#1

Can someone tell me the significance of /media/linaro/00BC-614E/… I have noticed this on DB410 base image… Where is this mount created, and for what purpose?


#2

Debian uses udisks2 which is started by default at boot/login. This service will try to mount any available file system (on removable disk, I think) in /media.

So /media/linaro/<ID> represents a file system mounted by udisks, while you are logged as ‘linaro’ user.

If you run the ‘mount’ command in a terminal it will show you the list of all mounted file system and you will find it there.

On our image, this very likely correspond to the ‘modem’ partition on the eMMC which contains a FAT file system with the DSP firmware.


#3

@ndec

Thanks for clarifying. Part of my initial puzzle was, if I run mount on a booted board over ssh session, I did not see /media/linaro/<id> in the list when I initially ran mount (prior to post).

So, I gather from your response it is contingent on the linaro user being logged into the machine (and possibly desktop up?)… hence, why I asked where the mount would occur.

If I have another user or rootfs without the linaro user, I was wondering what the implications might be for this <id> ? I have such an image, and this folder is missing…


#4

Hi @hhony,

I may not understanding your question completely but Debian is configured to mount automatically any partition found by udisks2.

And these are the messages of mount on my DB410C after installing this image.
https://github.com/96boards/documentation/wiki/DragonBoard%E2%84%A2-410c-Linaro-Debian-Download#your-build-choice

Without any SD card inserted on DB410C.


root@linaro-alip:~# mount
.....
/dev/mmcblk0p1 on /media/linaro/00BC-614E type vfat (rw,nosuid,nodev,relatime,u)
root@linaro-alip:~# ls /media/linaro/00BC-614E/
image  verinfo

If I insert SD card to DB410C


root@linaro-alip:~# mount
.....
/dev/mmcblk0p1 on /media/linaro/00BC-614E type vfat (rw,nosuid,nodev,relatime,u)
/dev/mmcblk1p1 on /media/linaro/boot type vfat (rw,nosuid,nodev,relatime,uid=10)
/dev/mmcblk1p2 on /media/linaro/rootfs type ext4 (rw,nosuid,nodev,relatime,data)
root@linaro-alip:~# ls -l /media/linaro/
total 36
drwx------  4 linaro linaro 16384 Jan  1  1970 00BC-614E
drwx------  2 linaro linaro 16384 Jan  1  1970 boot
drwxr-xr-x 21 root   root    4096 Apr 27 10:20 rootfs

The directly “/media/linaro/” of rootfs is initially empty and the “00BC-614E, boot, rootfs” are made during boot by when they are mounted to /media/linaro/ depends on /dev/disk/by-label/ or /dev/disk/by-uuid/.

I hope this clarify your question.


#5

@Akira Tsukamoto

Thank you again, I think that answered my suspicions. You confirmed part of it I think - I have trimmed the rootfs substantially. I am not using automount (hdmi, keyboard or mouse… and basically headless)… so this could also be part of the question as to: ‘what about that folder’.

I suppose I could setup rules and such… but I have a custom app that manages the sd mount quiet efficiently, as I prefer it.

I believe, perhaps, I need more information about each of the partitions on emmc to understand this question fully. I have tracked down a few places on the web about p1-p10, and observed the symlinks in /dev/disk/by-label and /dev/disk/by-uuid prior to my post. Although, I haven’t had the time to go in depth, yet, as I’ve been busy with other things… plus I’ve lost those links as they didn’t make it into bookmarks.

Do you have a documentation link for partitions? This would probably clear it all up for me. I believe I last found something on a blind search within the context of fastboot flash <label>(?) It may have been android documentation even, although I’m really only interested in the linux parts for an embedded application.

From the flashall script in emmc rescue, I can see the labels: rootfs boot hyp modem rpm sbl1 sec tz aboot, and so I aware of the corresponding binaries’ existences… but I really need better documentation to fully utilize their functionality.

Should there be a symlink in by-label as well? In the latest build, I would like to understand the full correlation for the underlying partition’s purpose… :slight_smile:

I’ve rolled my own kernel and rootfs, haven’t gotten to boot, much less secure boot, stuff yet… but soon enough. I understand some of the limitations that apply there… and open frameworks available for other hardware.

Back to my original question:
I don’t really care about booting from sd, and so perhaps this is less of a concern?