[PATCH v7 0/5] Add support for K230 board

[Chao Liu <chao.liu.zevorn@gmail.com>]

This patch series adds support for U-Boot + OpenSBI + standard Linux kernel on
K230 board. Thanks to Peng Jiang, Mig Yang, Renzao Ren, Yao Zi for their help.

The current patchset fixes some bug and tag errors, Thanks to Alistair and
Conor for the review.

Test command with the direct Linux boot:

```
$QEMU -M k230 \
      -kernel [Image] \
      -dtb [k230-qemu.dtb] \
      -initrd [rootfs.cpio.gz] \
      -nographic
```

The k230-boot-assets repo [1] provides K230 Linux kernel images built with
k230-sdk and Yocto.

For more information, see docs/system/riscv/k230.rst.

The GitLab CI result [2] passed all cases.

PATCH v7 changelog:
- Patchset: Removed invalid tags for patchset.
- Patchset: Updated the K230 datasheet link in the patchset comment header.
- Patch 2: Removed the unnecessary changes to MAINTAINERS.
- Patch 2: Fixed an Oops caused by accesses to an unimpl UART MMIO address.
- Patch 2: Adjusted the K230 machine hart count to 1.
- Patch 2: Supported direct boot linux with `-kernel`.
- Patch 3: Aligned the WDT interrupt number with the K230 datasheet.
- Patch 5: Updated k230.rst Linux boot docs.

PATCH v6 changelog:
- Patchset: Rebased on the latest Alistair's riscv-to-apply.next branch [3].
- Patch 4: Picked up Fabiano's Acked-by.

PATCH v5 changelog:
- Patchset: Rebased on Alistair's riscv-to-apply.next branch.
- Patch 2: Fixed reset vector ROM jump to trap-handler bug.

PATCH v4 changelog:
- Patchset: Rebased on the latest master branch.
- Patchset: No functional changes from v3.

PATCH v3 changelog:
- Patch 1: Align T-Head C908 CPU's RISC-V extension with XUANTIE-QEMU.
- Patch 2: Adjust PLIC and CLINT addresses to match K230 datasheet.

PATCH v2 changelog:
- Patch 1: Add Svpbmt extension support for the T-Head C908 CPU.
- Patch 2: Move the k230.rst definition from MAINTAINERS to Patch 5.
- Patch 5: Apply Daniel's bugfix to build the k230 documentation successfully.

PATCH v1 changelog:
- Patch 1: Add T-Head C908 and C908v CPU support.
- Patch 2: Add K230 board initial support(big core is not supported yet).
- Patch 3: Add Programmable Watchdog Timer (WDT) peripheral support.
- Patch 4: Add QEMU test for K230 watchdog.
- Patch 5: Add documentation for K230 machine.

---

Link:
[1] https://github.com/zevorn/k230-boot-assets
[2] https://gitlab.com/chao23.liu/qemu/-/pipelines/2515556858
[3] https://github.com/alistair23/qemu/tree/riscv-to-apply.next

Thanks,
Chao

Chao Liu (5):
  target/riscv: add thead-c908 cpu support
  hw/riscv: add k230 board initial support
  hw/watchdog: add k230 watchdog initial support
  tests/qtest: add test for K230 watchdog
  docs/system/riscv: add documentation for k230 machine

 MAINTAINERS                    |  11 +
 docs/system/riscv/k230.rst     | 113 +++++++
 docs/system/target-riscv.rst   |   1 +
 hw/riscv/Kconfig               |  11 +
 hw/riscv/k230.c                | 524 +++++++++++++++++++++++++++++++++
 hw/riscv/meson.build           |   2 +-
 hw/watchdog/Kconfig            |   4 +
 hw/watchdog/k230_wdt.c         | 296 +++++++++++++++++++
 hw/watchdog/meson.build        |   1 +
 hw/watchdog/trace-events       |   9 +
 include/hw/riscv/k230.h        | 149 ++++++++++
 include/hw/watchdog/k230_wdt.h | 121 ++++++++
 target/riscv/cpu-qom.h         |   2 +
 target/riscv/cpu.c             |  51 ++++
 target/riscv/th_csr.c          | 380 +++++++++++++++++++++++-
 tests/qtest/k230-wdt-test.c    | 189 ++++++++++++
 tests/qtest/meson.build        |   3 +-
 17 files changed, 1864 insertions(+), 3 deletions(-)
 create mode 100644 docs/system/riscv/k230.rst
 create mode 100644 hw/riscv/k230.c
 create mode 100644 hw/watchdog/k230_wdt.c
 create mode 100644 include/hw/riscv/k230.h
 create mode 100644 include/hw/watchdog/k230_wdt.h
 create mode 100644 tests/qtest/k230-wdt-test.c