rules/rv.bzl

# Copyright lowRISC contributors.
# Licensed under the Apache License, Version 2.0, see LICENSE for details.
# SPDX-License-Identifier: Apache-2.0

"""Helpers for transitioning to the RISC-V target."""

OPENTITAN_CPU = "@platforms//cpu:riscv32"
OPENTITAN_PLATFORM = "@bazel_embedded//platforms:opentitan_rv32imc"

# This constant holds a dictionary of per-device dependencies which are used to
# generate slightly different binaries for each hardware target, including two
# simulation platforms (DV and Verilator), and two FPGA platforms (NexysVideo
# and CW310).
PER_DEVICE_DEPS = {
    "sim_verilator": ["//sw/device/lib/arch:sim_verilator"],
    "sim_dv": ["//sw/device/lib/arch:sim_dv"],
    "fpga_nexysvideo": ["//sw/device/lib/arch:fpga_nexysvideo"],
    "fpga_cw310": ["//sw/device/lib/arch:fpga_cw310"],
}

def _opentitan_transition_impl(settings, attr):
    return {"//command_line_option:platforms": attr.platform}

opentitan_transition = transition(
    implementation = _opentitan_transition_impl,
    inputs = [],
    outputs = ["//command_line_option:platforms"],
)

def rv_rule(**kwargs):
    """
    A wraper over rule() for painlessly creating rules that trigger the opentitan
    transition.
    """

    attrs = kwargs.pop("attrs", {})
    if "platform" not in attrs:
        attrs["platform"] = attr.string(default = OPENTITAN_PLATFORM)
    attrs["_allowlist_function_transition"] = attr.label(
        default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
    )

    return rule(
        cfg = opentitan_transition,
        attrs = attrs,
        **kwargs
    )