Arch Linux

Frefreak

Member

Registered: 2013-12-18

Posts: 25

[SolvedHow to connect SD/MMC card to the computer as /dev/mmc* device?

I want to interact with an eMMC card at low level (using ioctl, etc). I have tested with an SD card reader(connects to the PC via usb) and a SD card, which when inserted, is recognized as /dev/sd* device instead of /dev/mmcblk* stuff.

$ lsusb
Bus 002 Device 006: ID 14cd:1212 Super Top microSD card reader (SY-T18)
Bus 002 Device 003: ID 18e3:9106 Fitipower Integrated Technology Inc 
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 004: ID 046d:c31c Logitech, Inc. Keyboard K120
Bus 001 Device 003: ID 046d:c077 Logitech, Inc. M105 Optical Mouse
Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

$ dmesg | tail
[ 2633.010126] usb-storage 2-1.4:1.0: USB Mass Storage device detected
[ 2633.011141] scsi host9: usb-storage 2-1.4:1.0
[ 2634.016184] scsi 9:0:0:0: Direct-Access     Mass     Storage Device   1.00 PQ: 0 ANSI: 0 CCS
[ 2634.201201] sd 9:0:0:0: [sdf] 15130624 512-byte logical blocks: (7.74 GB/7.21 GiB)
[ 2634.201804] sd 9:0:0:0: [sdf] Write Protect is off
[ 2634.201807] sd 9:0:0:0: [sdf] Mode Sense: 03 00 00 00
[ 2634.202480] sd 9:0:0:0: [sdf] No Caching mode page found
[ 2634.202488] sd 9:0:0:0: [sdf] Assuming drive cache: write through
[ 2634.206572]  sdf: sdf1
[ 2634.209173] sd 9:0:0:0: [sdf] Attached SCSI removable disk

$ lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 465.8G  0 disk 
├─sda1   8:1    0   460G  0 part /
└─sda2   8:2    0   5.8G  0 part [SWAP]
sdf      8:80   1   7.2G  0 disk 
└─sdf1   8:81   1   7.2G  0 part 
sr0     11:0    1  1024M  0 rom 

I tried with some code online to send CMD to /dev/sdf or /dev/sdf1 but it just failed. So how could I make it recognize my sd card as /dev/mmcblk0 (or something similar), not /dev/sdf? My computer doesn't have a build-in SD card slot.

Note: I can use it as normal storage device without problems.

Last edited by Frefreak (2015-09-18 08:26:25)

frostschutz

Member

Registered: 2013-11-15

Posts: 1,647

Re: [SolvedHow to connect SD/MMC card to the computer as /dev/mmc* device?

I don't think you can - it depends on the cardreader. I have /dev/mmc* on an embedded device with builtin slots; USB cardreaders tend to be regular mass storage devices which end up as /dev/sd*.

Frefreak

Member

Registered: 2013-12-18

Posts: 25

Re: [SolvedHow to connect SD/MMC card to the computer as /dev/mmc* device?

I don't think you can - it depends on the cardreader. I have /dev/mmc* on an embedded device with builtin slots; USB cardreaders tend to be regular mass storage devices which end up as /dev/sd*.

Is there any card reader can make it? (connect to computer via USB and been recognized as /dev/mmc*)

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: [SolvedHow to connect SD/MMC card to the computer as /dev/mmc* device?

CONFIG_MMC_VUB300:

This selects support for Elan Digital Systems' VUB300 chip.

The VUB300 is a USB-SDIO Host Controller Interface chip
that enables the host computer to use SDIO/SD/MMC cards
via a USB 2.0 or USB 1.1 host.

The VUB300 chip will be found in both physically separate
USB to SDIO/SD/MMC adapters and embedded on some motherboards.

The VUB300 chip supports SD and MMC memory cards in addition
to single and multifunction SDIO cards.

Some SDIO cards will need a firmware file to be loaded and
sent to VUB300 chip in order to achieve better data throughput.
Download these "Offload Pseudocode" from Elan Digital Systems'
web-site http://www.elandigitalsystems.com/support/downloads.php
and put them in /lib/firmware. Note that without these additional
firmware files the VUB300 chip will still function, but not at
the best obtainable data rate.

To compile this mmc host controller driver as a module,
choose M here: the module will be called vub300.

If you have a computer with an embedded VUB300 chip
or if you intend connecting a USB adapter based on a
VUB300 chip say Y or M here.

Good luck

Frefreak

Member

Registered: 2013-12-18

Posts: 25

Re: [SolvedHow to connect SD/MMC card to the computer as /dev/mmc* device?

CONFIG_MMC_VUB300:

This selects support for Elan Digital Systems' VUB300 chip.

The VUB300 is a USB-SDIO Host Controller Interface chip
that enables the host computer to use SDIO/SD/MMC cards
via a USB 2.0 or USB 1.1 host.

The VUB300 chip will be found in both physically separate
USB to SDIO/SD/MMC adapters and embedded on some motherboards.

The VUB300 chip supports SD and MMC memory cards in addition
to single and multifunction SDIO cards.

Some SDIO cards will need a firmware file to be loaded and
sent to VUB300 chip in order to achieve better data throughput.
Download these "Offload Pseudocode" from Elan Digital Systems'
web-site http://www.elandigitalsystems.com/support/downloads.php
and put them in /lib/firmware. Note that without these additional
firmware files the VUB300 chip will still function, but not at
the best obtainable data rate.

To compile this mmc host controller driver as a module,
choose M here: the module will be called vub300.

If you have a computer with an embedded VUB300 chip
or if you intend connecting a USB adapter based on a
VUB300 chip say Y or M here.

Good luck

Thanks for the info. The VUB300 chip seems a little bit hard for me to get so I have decided to use an embedded Linux board in my lab to try the experiments.