[bazel] Autogen Rust register modules

Signed-off-by: James Wainwright <[email protected]>

Author: jwnrt

hw/top/BUILD

@@ -7,6 +7,7 @@ load("@bazel_skylib//rules:common_settings.bzl", "string_flag")
 load(
     "//rules:autogen.bzl",
     "opentitan_ip_c_header",
+    "opentitan_ip_rust_module",
 )
 load("//rules/opentitan:hw.bzl", "get_top_attr")
 load(
@@ -18,6 +19,7 @@ load(
     "opentitan_alias_top_attr",
     "opentitan_if_ip",
 )
+load("@rules_rust//rust:defs.bzl", "rust_library")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -125,6 +127,51 @@ alias(
     for ip in ALL_IP_NAMES
 ]
 
+# Rust register modules for all IPs.
+[
+    opentitan_ip_rust_module(
+        name = "{}_rust_regs".format(ip),
+        ip = ip,
+        kind = "generic",
+    )
+    for ip in ALL_IP_NAMES
+]
+
+# `lib.rs` file defining a module for each IP.
+genrule(
+    name = "ot_regs_lib_rs",
+    srcs = [],
+    outs = ["lib.rs"],
+    cmd = "echo '{}' > \"$@\"".format(
+        "\n".join([
+            '#[cfg(feature = "{ip}")]\npub mod {ip};'.format(ip = ip)
+            for ip in ALL_IP_NAMES
+        ]),
+    ),
+    visibility = ["//visibility:private"],
+)
+
+# Crate with a module for the registers of each IP.
+rust_library(
+    name = "ot_regs",
+    srcs = [":ot_regs_lib_rs"] + flatten([
+        opentitan_if_ip(
+            ip,
+            [":{}_rust_regs".format(ip)],
+            [],
+        )
+        for ip in ALL_IP_NAMES
+    ]),
+    crate_features = flatten([
+        opentitan_if_ip(
+            ip,
+            [ip],
+            [],
+        )
+        for ip in ALL_IP_NAMES
+    ]),
+)
+
 cc_library(
     name = "doxy_target",
     deps = [

hw/top/README.md

@@ -42,6 +42,7 @@ Furthermore, adding `//hw/top:top_lib` or `//hw/top:top_ld` as a dependency of a
 
 The headers for every IP are exposed as:
 - `//hw/top:<ip>_c_regs` for the C registers,
+- `//hw/top:<ip>_rust_regs` for the Rust registers,
 - `//hw/top/tock:<ip>_regs` for the Rust registers for Tock.
 
 [**Compatibility annotations**](#compatibility-annotations): those targets are only marked as compatible with the tops that contain at least an instance of them.