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Re: Unaligned access in kernel on ARMv6+ (Re: CVS commit: src/sys/dev/usb)



On Sun, Jan 06, 2019 at 08:31:53AM -0500, Greg Troxel wrote:
> Why do we generate code with unaligned access in user space?  That seems
> surprising, if the processor isn't happy about it.

The processor is happy with it, both in user- and kernel space.
Only special memory regions mapped uncached make it trap.

Nick suggest to change the mapping for bus_dma to cached, which would avoid
the issue but may expose bugs in device drivers.

Martin


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