3 ms·
Unfortunately that means the chunks are only contiguous in virtual memory. So it won't work with the DMA use case mentioned in the article, which requires conti
by dist1ll 3y ago
Unfortunately that means the chunks are only contiguous in virtual memory. So it won't work with the DMA use case mentioned in the article, which requires contiguous physical addresses.
But it's still a nice trick, I like it when people get creative with HW features.
- jnwatson 3y agoTheoretically, the same trick could be used to double map addresses coming from an external master via an IOMMU.
- speed_spread 3y agoIt is unlikely that cheap microcontrollers where DMA is most helpful will have an IOMMU.
- gpderetta 3y agoBut the hardware only needs to see on copy of the duplicated memory and you can let it deal with the wraparound. The software can use the convenience of the double mapping.