4 ms·

MFi is quite literally DRM for USB [1][2][3]!! You're probably confused by the form factor (Lightning vs USB-C), and understandably so. The MFi program prevents

MFi is quite literally DRM for USB [1][2][3]!! You're probably confused by the form factor (Lightning vs USB-C), and understandably so. The MFi program prevents successful USB link establishment for non DRM-ed (i.e. unauthorized ) accessories. It's quite literally a toll on the USB lane that Apple can get away with [1]: http://ramtin-amin.fr/#tristar http://ramtin-amin.fr/#tristar [2]: https://en.wikipedia.org/wiki/Lightning_(connector) https://en.wikipedia.org/wiki/Lightning_(connector) [3]: https://en.wikipedia.org/wiki/MFi_Program https://en.wikipedia.org/wiki/MFi_Program

eridius 8y ago
MFi covers Apple's proprietary connectors, as well as certain Apple wireless protocols. It does not cover generic USB. If you want more proof, every since the iPad came out Apple has actually sold a USB-A port for the iPad, called a "Camera Adapter" (e.g. Lightning to USB 3 Camera Adapter[1]). It's called this because the primary use-case is connecting your camera to your iPad in order to transfer photos off of it (similar to connecting an SD card), but it works with other USB accessories such as card readers, MIDI interfaces, ethernet adapters, etc. In fact, I'd assume that it works with precisely the same set of accessories that can plug directly into the USB-C port on the new iPad (well, except for being USB-A instead of USB-C). None of these USB accessories are part of the MFi program. Because they don't need to be. Because they're generic USB accessories, rather than accessories that use Lightning or 30-pin connectors. [1] https://www.apple.com/shop/product/MK0W2AM/A/lightning-to-usb-3-camera-adapter https://www.apple.com/shop/product/MK0W2AM/A/lightning-to-us...
- writepub 8y ago
  Products you've cited do implement MFI DRM themselves, like Apple's SD reader. It has an MFI DRM chip, plenty of teardowns are online. Additionally, the original post is about USB-C storage accessories not working with the new iPad Pros. So, there's ample evidence that Apple can indeed enforce DRM over USB It's trivial to connect an MFI/USB protocol analyzer to the USB-C bus, and watch the DRM in action yourself. Cheers
  - eridius 8y ago
    Apple's SD card reader is a Lightning accessory. Of course it has MFi. But you can plug a generic USB SD card reader in to your iPad using Apple's Lightning to USB 3 Camera Adapter and that works just fine, even though the generic USB SD card reader does not have an MFI chip. Similarly you can plug a camera in (which is the original purpose of that adapter), or an ethernet adapter, or a MIDI interface, or more, none of which have MFi chips and yet work just fine when plugged in via Apple's Lightning to USB 3 Camera Adapter. The fact that generic storage devices don't work has nothing at all to do with MFi and everything to do with the fact that iOS simply doesn't implement support for them.
    - writepub 8y ago
      You are right that iOS has no native OS support for USB storage devices - precisely because Apple restricts access to them via MFI. i.e. as a storage accessory manufacturer, you need to add an MFI DRM chipset and pass MFI certification for Apple to allow a USB link with iOS. Here [1] are a scores of iOS USB flash drives (over lightning), all communicating with iOS via the USB 2.0 bulk storage protocol, after DRM-passing via the MFI chip they are forced to include in their hardware. Further - you are right that iOS doesn't support USB mass storage at the kernel layer - the accessory manufacturer is forced to write a user-space driver within the app advertised for said accessory. The iPad Pro doesn't work out of the box with over the shelf USB-C storage accessories because: 1. iOS has disabled USB mass storage at the kernel level to enforce DRM via the MFI program 2. Since off-the-shelf USB-C storage devices are unlikely to have added a $X MFI chip to their accessory, Apple's DRM simply blocks a USB 2.0 link from being established. So - in conclusion, USB Mass storage - a feature widely available in mobile, and desktop computing since the dawn of the spec has been crippled by Apple on purpose to milk money [1]: https://www.google.com/search?biw=1680&bih=939&tbm=shop&ei=bWzjW_G7IYXc0gL7jLa4DQ&q=iphone+flash+drive&oq=iphone+flash+drive&gs_l=psy-ab.3..0l6.17466.23062.0.23199.26.12.5.9.10.0.168.926.10j2.12.0....0...1c.1.64.psy-ab..0.25.863...0i10k1j0i13k1.0.vatn_BIUPiU https://www.google.com/search?biw=1680&bih=939&tbm=shop&ei=b...
      - eridius 8y ago

eridius 8y ago

MFi covers Apple's proprietary connectors, as well as certain Apple wireless protocols. It does not cover generic USB. If you want more proof, every since the iPad came out Apple has actually sold a USB-A port for the iPad, called a "Camera Adapter" (e.g. Lightning to USB 3 Camera Adapter[1]). It's called this because the primary use-case is connecting your camera to your iPad in order to transfer photos off of it (similar to connecting an SD card), but it works with other USB accessories such as card readers, MIDI interfaces, ethernet adapters, etc. In fact, I'd assume that it works with precisely the same set of accessories that can plug directly into the USB-C port on the new iPad (well, except for being USB-A instead of USB-C). None of these USB accessories are part of the MFi program. Because they don't need to be. Because they're generic USB accessories, rather than accessories that use Lightning or 30-pin connectors. [1] https://www.apple.com/shop/product/MK0W2AM/A/lightning-to-usb-3-camera-adapter https://www.apple.com/shop/product/MK0W2AM/A/lightning-to-us...

writepub 8y ago
Products you've cited do implement MFI DRM themselves, like Apple's SD reader. It has an MFI DRM chip, plenty of teardowns are online. Additionally, the original post is about USB-C storage accessories not working with the new iPad Pros. So, there's ample evidence that Apple can indeed enforce DRM over USB It's trivial to connect an MFI/USB protocol analyzer to the USB-C bus, and watch the DRM in action yourself. Cheers
- eridius 8y ago
  Apple's SD card reader is a Lightning accessory. Of course it has MFi. But you can plug a generic USB SD card reader in to your iPad using Apple's Lightning to USB 3 Camera Adapter and that works just fine, even though the generic USB SD card reader does not have an MFI chip. Similarly you can plug a camera in (which is the original purpose of that adapter), or an ethernet adapter, or a MIDI interface, or more, none of which have MFi chips and yet work just fine when plugged in via Apple's Lightning to USB 3 Camera Adapter. The fact that generic storage devices don't work has nothing at all to do with MFi and everything to do with the fact that iOS simply doesn't implement support for them.
  - writepub 8y ago
    You are right that iOS has no native OS support for USB storage devices - precisely because Apple restricts access to them via MFI. i.e. as a storage accessory manufacturer, you need to add an MFI DRM chipset and pass MFI certification for Apple to allow a USB link with iOS. Here [1] are a scores of iOS USB flash drives (over lightning), all communicating with iOS via the USB 2.0 bulk storage protocol, after DRM-passing via the MFI chip they are forced to include in their hardware. Further - you are right that iOS doesn't support USB mass storage at the kernel layer - the accessory manufacturer is forced to write a user-space driver within the app advertised for said accessory. The iPad Pro doesn't work out of the box with over the shelf USB-C storage accessories because: 1. iOS has disabled USB mass storage at the kernel level to enforce DRM via the MFI program 2. Since off-the-shelf USB-C storage devices are unlikely to have added a $X MFI chip to their accessory, Apple's DRM simply blocks a USB 2.0 link from being established. So - in conclusion, USB Mass storage - a feature widely available in mobile, and desktop computing since the dawn of the spec has been crippled by Apple on purpose to milk money [1]: https://www.google.com/search?biw=1680&bih=939&tbm=shop&ei=bWzjW_G7IYXc0gL7jLa4DQ&q=iphone+flash+drive&oq=iphone+flash+drive&gs_l=psy-ab.3..0l6.17466.23062.0.23199.26.12.5.9.10.0.168.926.10j2.12.0....0...1c.1.64.psy-ab..0.25.863...0i10k1j0i13k1.0.vatn_BIUPiU https://www.google.com/search?biw=1680&bih=939&tbm=shop&ei=b...
    - eridius 8y ago