[PATCH v2 0/7] target/riscv: Initial support for native debug feature via M-mode CSRs

[Bin Meng <bmeng.cn@gmail.com>]

This adds initial support for the native debug via the Trigger Module,
as defined in the RISC-V Debug Specification [1].

Only "Address / Data Match" trigger (type 2) is implemented as of now,
which is mainly used for hardware breakpoint and watchpoint. The number
of type 2 triggers implemented is 2, which is the number that we can
find in the SiFive U54/U74 cores.

[1] https://github.com/riscv/riscv-debug-spec/raw/master/riscv-debug-stable.pdf

Based-on: 20211030030606.32297-1-bmeng.cn@gmail.com

Changes in v2:
- new patch: add debug state description
- use 0 instead of GETPC()
- change the config option to 'disabled' by default
- new patch: enable native debug feature on virt and sifive_u CPUs

Bin Meng (7):
  target/riscv: Add initial support for native debug
  target/riscv: machine: Add debug state description
  target/riscv: debug: Implement debug related TCGCPUOps
  target/riscv: cpu: Add a config option for native debug
  target/riscv: csr: Hook debug CSR read/write
  target/riscv: cpu: Enable native debug feature on virt and sifive_u
    CPUs
  hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint()

 include/hw/core/tcg-cpu-ops.h |   1 +
 target/riscv/cpu.h            |   7 +
 target/riscv/debug.h          | 114 +++++++++
 target/riscv/cpu.c            |  18 ++
 target/riscv/csr.c            |  57 +++++
 target/riscv/debug.c          | 441 ++++++++++++++++++++++++++++++++++
 target/riscv/machine.c        |  33 +++
 target/riscv/meson.build      |   1 +
 8 files changed, 672 insertions(+)
 create mode 100644 target/riscv/debug.h
 create mode 100644 target/riscv/debug.c

-- 
2.25.1