4 ms·
You can limit them with IOMMUs. It's reduced to the power of a hostile process. Well, that's still bad if you're booted off it.
by astrange 1y ago
You can limit them with IOMMUs. It's reduced to the power of a hostile process.
Well, that's still bad if you're booted off it.
- fluoridation 1y agoOn i486?
- toast0 1y agoAn i486 certainly doesn't have an integrated iommu, and none of the chipsets for 486s had them either (afaik), but that doesn't mean you can't add one if you're building up your system from scratch.
- jacquesm 1y agoOr you could forego DMA completely if you wanted. Almost all DMA capable devices have some kind of non-DMA route to access the data. It may be slower and it would of course still enable an adversary with access to your hardware to replace the device you boot from with one that has compromised data on it. But at that level it is usually game over anyway. I was thinking of just using an SD card, and if you're really paranoid about this (which I am!) you could glue it into the slot or make it physically impossible to replace it without damage to the case.
- fluoridation 1y agoWhat's the goal here, out of curiosity?
- jacquesm 1y agoGood question :) Roughly what Bunny was after, not in laptop format, and running my own, recently revived OS. Effectively a machine of which I know each and every byte.