"Unfortunately not, it's more of a suggestion. The switch doesn't actually do anything to prevent writes to the card."
In fact it is more than a simple suggestion. On good quality SD it disconnects the flash memory write pins. Yes cheaper just do suggestion. This suggestion is picked up by the controller as well that also blocks writing.
I know this from the Raspberry PI. The write protect wire is not connected on the Raspberry PI. So the cards that the write protect is a simple suggestion it will write. I have some SD cards the Raspberry PI cannot write to when the SD switch is set to write protect. Yes some cards have physical lock in card.
So yes a lot of Chromebooks SD can be set read only by the suggestion to controller that a software attack cannot override and will prevent all writes. Because the controller obeys the suggestion.
Final method to secure a SD card against writing is order a batch of custom Read only cards these don't contain flash at all. Something larger groups can do.
There is a reason why I said a Lot not all. There are some hardware varation that require some careful handling like the right brands SD cards with working write protect switches. Other chromebooks a SD card with switch set is enough because controller is picking up the load. Those will not notice if you use a better quality SD with real write switch.
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Re: Lot of chromebooks could be secured.
Date: 2013-02-05 07:45 am (UTC)In fact it is more than a simple suggestion. On good quality SD it disconnects the flash memory write pins. Yes cheaper just do suggestion. This suggestion is picked up by the controller as well that also blocks writing.
I know this from the Raspberry PI. The write protect wire is not connected on the Raspberry PI. So the cards that the write protect is a simple suggestion it will write. I have some SD cards the Raspberry PI cannot write to when the SD switch is set to write protect. Yes some cards have physical lock in card.
So yes a lot of Chromebooks SD can be set read only by the suggestion to controller that a software attack cannot override and will prevent all writes. Because the controller obeys the suggestion.
Final method to secure a SD card against writing is order a batch of custom Read only cards these don't contain flash at all. Something larger groups can do.
There is a reason why I said a Lot not all. There are some hardware varation that require some careful handling like the right brands SD cards with working write protect switches. Other chromebooks a SD card with switch set is enough because controller is picking up the load. Those will not notice if you use a better quality SD with real write switch.