8dea2908b7
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 draft version of the RISC-V debug spec, as of April 26th. This version fixes a number of spec bugs and should be close to the final debug spec.