Why do MMC cards work, but SD cards don't?

The SD Card Association(http://www.sdcard.org/) product license agreement does not allow open source drivers for the SD cards. The Multimedia Card Association(http://www.mmca.org/) (which came before SD) does allow Open Source drivers. See more details in the HandHeld.org documentation(http://www.handhelds.org/projects/h3800.html).

Linux Compatibility of Built-In MMC/SD-Card Readers

Here are some Linux laptop and notebook installation reports, which describe the configuration of the MMC or Secure Digital Host Controller Interface driver.

ACER Aspire 9814WKMi(http://samuel.benoit.online.fr/en/opensuse-11.0-linux-acer-aspire-9814-wkmi-9800-series-kde-4)	KUbuntu 6.10 Edgy Eft, 7.04, Novell/SuSE 11.0 AMD64 (x86_64)
ACER TravelMate 426LC(http://www.krutzke.net/linux/acer_travelmate_426lc_mit_suse_linux_10.1.html)	Novell/SuSE 10.1	German
ASUS M6800N(http://www.ngolde.de/laptop.html)	Debian
Compal CL56(http://wiki.archlinux.org/index.php/Compal_CL56)	ARCHlinux
COMPAQ TC4200(http://www.ser1.net/Files/Reviews/HP4200/index.html)	Gentoo
DELL Inspiron 630M(http://www.disgruntledgoat.com/content/useful/gentoo_on_inspiron630m.php)	Gentoo
DELL Inspiron 630M	Ubuntu 5.10 Breezy Badger, Dapper Drake
DELL Inspiron 6000(http://www.fam-lindeman.nl/content/view/12/34/)	Debian
DELL Inspiron 6000(http://www.martinhenze.de/2006/01/05/ubuntu-linux-on-dell-inspiron-6000/)	Ubuntu 5.10 Breezy Badger
DELL Inspiron 6400(http://individual.utoronto.ca/jaelle_kitty/inspiron6400/)	Ubuntu Breezy
DELL Latitude X1(http://friki.org/descarregues/manuals/x1/)	Debian	Catalan
DELL Latitude X1(http://gentoo-wiki.com/HARDWARE_Dell_Latitude_X1)	Gentoo
Fujitsu-Siemens Lifebook E-8210(http://jmaurer.awardspace.info/e8210.html)	Linux
HP/COMPAQ NC6400(http://bb.cactii.net/archives/000174.php)	KUbuntu Edgy
HP/COMPAQ NX6325(http://www.puchalla-online.de/nx6325.html)	Debian
IBM ThinkPad Z60m(http://de.gentoo-wiki.com/IBM_ThinkPad_Z60M)	Gentoo	German
IBM ThinkPad Z61m(http://www.onderka.com/index.php/category/notebooks/ibm-thinkpad-z61m/)	Gentoo
IBM ThinkPad Z61m(http://www.geekland.de/category/linux/)	Novell/SuSE 10.2	German
Medion MD42200(http://34474.dynamicboard.de/f48-Kubuntu.html)	KUbuntu 7.04	German
Packard Bell EasyNote A7718(https://wiki.ubuntu.com/LaptopTestingTeam/PackardBellA7718)	Ubuntu
Samsung P30 1500 XVM(http://www.int21.de/samsung/)	Gentoo
Samsung Q35(http://www.infolexikon.de/73)	ARCHlinux	German
Sony VAIO VGN-AR21B(http://www.arakhne.org/rubrique.php3?id_rubrique=26)	Ubuntu

Have you written a compatibility guide yourself? Then please feel free to submit a new entry.

Resources

• This site is an open collaboration effort for open source projects relating to the MultiMediaCard and SecureDigital protocols(http://mmc.drzeus.cx) . Currently it is mostly about the Linux implementations, but other systems such as BSD are welcome to participate.
• Texas Instruments 6xx1,7xx1 FlashMedia driver for Linux(http://www.webcon.ca/~imorgan/tifm21/)
• TI FlashMedia xx12/xx21 driver(http://developer.berlios.de/projects/tifmxx/) Alternative attempt to develop linux driver for TI FlashMedia xx12/xx21 storage controllers.
• SDCard.org(http://www.sdcard.org/)
• MMCA.org(http://www.mmca.org/)
• some notes about card readers with UniX(cardreader_unix.html)
• SD-MMC(https://opensource.motorola.com/sf/sfmain/do/viewProject/projects.sd-mmc): Open source implementation of the SD-MMC device drivers.
• sdricoh_cs(http://sourceforge.net/projects/sdricohcs/) is a Linux driver for Ricoh Secure Digital and MMC Card Readers that announce themselves as Ricoh Bay1Controller pcmcia device. These reader are used e.g. in some laptops made by Samsung and other notebook manufacturers.