Re: reliably set vtype.vill


Alex Solomatnikov
 

vsetvli x1, x0, e8, m8
vsetvli x0, x0, e16, m8

Alex

On Mon, Nov 1, 2021 at 9:46 AM Tim Newsome <tim@...> wrote:
I'm trying to set vill, and I can't think of a reliable way to do it.

This comes up when OpenOCD (a debugger) connects to a RV32 target where vtype contains (for instance) 0x80000000. The user asks to read the vector registers, and the debugger wants to use vtype so it can shift the register. When done, it wants to restore the original value so that there is no observable impact to the debugging.

Is there a way that I can write 0x80000000 to vtype?

Tim

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