Hallo, > On the enhanced SD card is then besides the normal flash storage also > the secure element (smart card). To access the smart card the file I/O > based interface is re-used, i.e. if you write something and it starts > with 'magics' in header and it is valid APDU command it is send to the > smart card instead of being saved to the flash memory - this is > handled by the on-card enhanced controller, which inspects the content > of the passed data (http://www.ctst.com/CTST08/pdf/Poitner.pdf, > http://www.gi-de.com/en/products_and_solutions/products/secure_microsd/product_details_4992.jsp).
Note that you would need an SD card that supports NFC-WI to be able to connect it to that interface. The products you mentioned above use a differnet approach (access trough direct APDU commands). As for the moment I don't know of any SD card that supports NFC-WI. > Now having the standard SD card slot in which is inserted the microSD > card with the secure element, which can be accessed by two above > mentioned ways - how this can be connected with the NXP 544 s2c > interface? Not at all. The secure element you described above can be accessed from the phone (trough some library like SEEK). It's not supposed to be connected to the NFC controller. > According to my understanding in the mode you are describing as an > 'internal' the NFC controller emits the same data like if it > communicates with the smart card over the radio, but instead of using > the RF antenna to send the data they are redirected over the wired s2c > bus to the SD card pins Right, if you have an NFC-WI enabled SD card this is pretty much how the internal mode works. > - so 2 selected SD card pins must be used for that. An SD card that supports NFC-WI would have that interface of course. > This also means the phone (Andorid) SD card driver be modified > to allow to send other than file I/O data and those data must be > understand by the controller on the SD card? No, if the SD card can be accessed through the NFC-WI, the two NFC-WI pins of the SD card would need to be connected to the two NFC-WI pins of the PN544 (i.e. hardware modifications, not software). This has nothing to do with the SD card driver. The SD card driver would handle the SD card's memory interface as usual. > Since the s2c is built on > the top of the ISO 18092 (right?) this protocol must be understand by > the on-card enhanced controller? Not ISO 18092 but the contactless protocol that is used by the secure element. In Europe this would typically be ISO 14443. > So the NXP 544 s2c bus must be somehow physically connected to the SD > card slot? Is that right? Yes. > Since the Nexus S already has the built-in SmartMX family (BTW – do > you know which chip is exactly used?) secure element how the SD card > secure element is selected? How the system understands to which secure > element it should talk, e.g. to embedded SmartMX or SD card? Or it is > not possible to use SD card when there is already embedded secure > element? Regarding the SD cards you linked above: These cards are completely independent from the NFC controller. Regarding a (teoretical) NFC-WI-enabled SD card: As NFC-WI is not really a bus but an interface between two endpoints, it would be difficult to have two secure elements connected to it. Possibly this could be done with some external multiplexing circuit. In general if a device contains multiple secure elements it would be the software's (or in the end the user's) decision which secure element to enable. But in general it is expected that only one secure element can be enabled at a time. > I know there is too much questions, but I try to understand if it is > at all possible to use the SD card or not and if it is possible, what > can be changed even in OS source code and if some HW changes in the > phones are necessary regarding the internal connection between NXP 544 > and SD card slot – you said "it will need some "special" hardware > support: To use SD card that support the NFC-WI, the SIGIN and SIGOUT > signal lines of the NFC-WI would need to be connected to the NFC > chip.". If true, is it already in the Google Nexus S, will this be in > the Galaxy SII? As I don't know of any SD cards that would actually support NFC-WI, I don't see why any manufacturer would integrate this into a device. br, Michael -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
