Making WP7607 appear as mass storage device

Legato Application Framework
1

Hi,

For a usecase I want my WP7607 to appear as a mass storage device when I plug it into a host PC (or any device that supports USB mass storage). I found an article that does this on a RPI: MAKE A PI ZERO W SMART USB FLASH DRIVE

I understand that I need to do modprobe g_mass_storage. But modules.dep is empty so that command returns an error. I checked Legato KConfig options but this doesn’t mention the option to customize any USB options.

Is it possible to add mass storage support to Legato? If yes, how?

2

seems no such option in AT!USBCOMP=?

at!usbcomp=?
!USBCOMP:
AT!USBCOMP=,,
- configuration index to which the composition applies, should be 1

- 1:Generic

- DIAG - 0x00000001,
NMEA - 0x00000004,
MODEM - 0x00000008,
RAWDAT - 0x00000040,
RMNET0 - 0x00000100,
RMNET1 - 0x00000400,
RMNET2 - 0x00000800,
AUDIO - 0x00010000,
ECM - 0x00080000,
NCM - 0x00400000,
e.g.
9 - diag,modem interfaces enabled
10D - diag,nmea,modem,rmnet0 interfaces enabled

OK

3

I know. But you can add it through KConfig, like this post: https://forum.mangoh.io/t/build-linux-for-wp76/1084/3

I was hoping the same could be achieved for mass storage. Maybe @dfrey knows?

4

@langestefan,

So this is possible as per the below (not generated by me).

Create an empty 32MB FAT image (in /tmp/fat.fs) using mkdosfs command:

dd if=/dev/zero of=/tmp/fat.fs bs=1024 count=32768
mkdosfs /tmp/fat.fs

Then mount this image in “/tmp/mass_storage” in order to add some files.

mount -o loop /tmp/fat.fs /tmp/mass_storage
echo "Hello World!" > /tmp/mass_storage/README.TXT

After that add/configure “mass_storage” in the USB functions:

echo 0 > /sys/class/android_usb/android0/enable
echo diag,serial,rmnet,ecm, **mass_storage** > /sys/class/android_usb/android0/functions
echo /tmp/fat.fs > /sys/class/android_usb/android0/f_mass_storage/lun/file
echo 1 > /sys/class/android_usb/android0/enable

After that, a new USB flash drive is visible on the host side (a PC in this case) with the expected content.

Regards

Matt

5

it works!
BTW, you can use the busybox here for mkdosfs command on WP76
busybox-armv5l_1.26 (1.1 MB)

root@swi-mdm9x28-wp:~# chmod 777 busybox-armv5l_1.26
root@swi-mdm9x28-wp:~# ./busybox-armv5l_1.26 mkdosfs /tmp/fat.fs

6

Here is an updated version of document which shows how to enumerate mass storage device for WP76 with FW R12 (kernel 3.18) and FW R17.1 (kernel 4.14) :