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Re: DMA buffer for PCI busmaster headache

Subject: Re: DMA buffer for PCI busmaster headache
by geennaam on 2021/3/3 22:58:06


So the only difference is that I do not need to perform a Cache flush manually?

What I do now is:
1. allocate a contiguous buffer which is physical aligned and is not allowed to be relocated with AllocVecTags(). This function returns the virtual address. (for OS4 access)

2. aqcuire the physical address in supervisor mode (for DMA controller access)

3. Perform a CacheClearE() after I've completed a write sequency to the memory region with the virtual address.

Anyways, that works like a charm now. But if it is more OS4 legal to do it with StartDMA()/EndDMA then I will switch of course.

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