When I disappeared the polls everywhere I forgot to sanitize the hartid
after halting.  This is an invariant that GDB expects: when you return
from a halt whatever thread is marked as currently selected is the
thread that the next register accesses reference.

When gcc isn't optimizing well, it might not realize that it's not
possible to return fd without initializing it, and then the build fails
due to -Werror.

GDB seems to just go off the rails if I return a SIGINT.

I missed this event.  It appears to do nothing.

This means I don't know what hart to look at, so I might as well
invalidate the register cache.  Without this, you might get stale
registers the first time you ask for them.

I thought OpenOCD did this, but it looks like that doesn't happen when
runningi in RTOS mode.  With this I can get to the end of most of the
RTOS tests, but they SIGINT instead of exiting.

riscv-v11: Don't perform unexpected operation in cache_write

This fixes a race condition when reading/writing memory.

The larger buffers are really slow on Spike.

This was just a sanity check.

GDB might request registers even if target was not successfully initialized.

Read from 0

This is another thing that should be fixed correctly.  Essentially this
just uses the old codepath, which works for v0.11.

I'm not sure why this is necessary, but for some reason GDB is asking
for registers before OpenOCD thinks there's been a halt.  This is really
just a workaround, but I need to refactor the v0.11 stuff anyway so I
don't want to figure it out.

This is a major rewrite of the RISC-V v0.13 OpenOCD port.  This
shouldn't have any meaningful effect on the v0.11 support, but it does
add generic versions of many functions that will allow me to later
refactor the v0.11 support so it's easier to maintain both ports.  This
started as an emergency feature branch and went on for a long time, so
it's all been squashed down into one commit so there isn't a big set of
broken commits lying around.  The changes are:

 * You can pass "-rtos riscv" to the target in OpenOCD's configuration
   file, which enables multi-hart mode.  This uses OpenOCD's RTOS
   support to control all the harts from the debug module using commands
   like "info threads" in GDB.  This support is still expermental.

 * There is support for RV64I, but due to OpenOCD limitations we only
   support 32-bit physical addresses.  I hope to remedy this by rebasing
   onto the latest OpenOCD release, which I've heard should fix this.

 * This matches the latest dra...

fespi: Reset may have occurred. Need to set TXWM again. There are probably more places that need this added.

Readmem autoexec