[PATCH v5 0/6] target/riscv: Initial support for the Sdtrig extension via M-mode CSRs

[Bin Meng]

This adds initial support for the Sdtrig extension 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

Changes in v5:
- rebase against riscv-to-apply.next
- drop patch 1 in v4 which is already in riscv-to-apply.next
- adjust patch order to let patch 2 in v4 come later

Changes in v4:
- move riscv_trigger_init() call to riscv_cpu_reset()

Changes in v3:
- add riscv_trigger_init(), moved from patch #1 to this patch
- enable debug feature by default for all CPUs

Changes in v2:
- use 0 instead of GETPC()
- change the config option to 'disabled' by default
- new patch: add debug state description

Bin Meng (6):
  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: machine: Add debug state description
  target/riscv: cpu: Enable native debug feature
  hw/core: tcg-cpu-ops.h: Update comments of debug_check_watchpoint()

 include/hw/core/tcg-cpu-ops.h |   1 +
 target/riscv/cpu.h            |   4 +-
 target/riscv/debug.h          |   6 ++
 target/riscv/cpu.c            |  12 ++++
 target/riscv/csr.c            |  57 +++++++++++++++++++
 target/riscv/debug.c          | 102 ++++++++++++++++++++++++++++++++++
 target/riscv/machine.c        |  32 +++++++++++
 7 files changed, 213 insertions(+), 1 deletion(-)

-- 
2.25.1