3 ms·
Sadly, the modems are on PCIe, so this means they are sharing memory and address space with the host iMX8.
by mondoshawan 7y ago
Sadly, the modems are on PCIe, so this means they are sharing memory and address space with the host iMX8.
- djsumdog 7y agoYea, if feels like if you wanted that kind of isolation, you'd actually need a second SoC on there with its own memory and some kind of communication back to the main processor.
- V4ASt2 7y agoSadly, you're wrong, and the phone modem is on the USB bus precisely for that reason.
- mondoshawan 7y agoSadly I am happy to be corrected! :D
- moosingin3space 7y agoYou can use an IOMMU to isolate DMA to a separate security domain. This is how Qubes OS works.
- mondoshawan 7y agoNo iommu on the imx8mq.
- moosingin3space 7y agoThat's unfortunate, since an IOMMU is an excellent solution to this kind of problem, especially when one considers all the potential Linux USB stack vulnerabilities that can be exploited if you assume the modem is untrustworthy.