TPM and GPL(v2)
Posted Jun 15, 2006 10:00 UTC (Thu) by simlo
Parent article: Interview: Harald Welte (part 1)
> On the technical front, I've heard some rumors that the A1200 and
> especially the later models will make use of the TPM (yes, the PXA270 has a
> TPM!) in order to ensure nobody boots non-Motorola-signed kernels. To me,
> this would be a clear violation of the intent of even GPLv2, and should
> those rumours become true, I'll certainly do anything to enforce my
> position on this. But as said, all rumours, nothing definitive known yet.
Well, I see nothing in GPLv2 which says you have to be able to run the software on a specific device. You can always build your own hardware or a simulator.
Would it also be against GPL to put the kernel on a ROM? Then you have to solder to update the software. That is doable, but what if that ROM is build into the CPU chip?
Going to the other extreme: Someone gives you a PC with Linux on a CDROM in the CDROM-drive. Oh! That is read-only, you can only change the Linux kernel by changing CDROM, i.e. changing hardware. Is that forbidden too?
I think using TPM technologies are not always evil. Legal requirements might make it illegal to sell phones where the user can manipulate the transmitter. TPM is a way to make it legally possible to use Linux on such phones. The only other alternative would be to use another OS and not publish the source code at all. Then I would prefer a phone running Linux, although I can't change the kernel. (Ofcourse, a good compromise would be if the phone can boot your own kernel, but just wouldn't be able to transmit, if it isn't signed.)
I can come up with other exambles, where having a device running a TPM locked Linux is the most preferable solution. I have before mentioned the idea of having intelligent electricity, water, heat meters running a trusted (by the provider, not the home owner) Linux.
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