1 files changed, 27 insertions, 8 deletions
diff --git a/pw_sys_io/BUILD.bazel b/pw_sys_io/BUILD.bazel
index fdba093be..4fa404f4b 100644
--- a/pw_sys_io/BUILD.bazel
+++ b/pw_sys_io/BUILD.bazel
@@ -14,6 +14,7 @@
 
 load(
     "//pw_build:pigweed.bzl",
+    "host_backend_alias",
     "pw_cc_facade",
     "pw_cc_library",
 )
@@ -22,6 +23,10 @@ package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])
 
+constraint_setting(
+    name = "backend_constraint_setting",
+)
+
 pw_cc_facade(
     name = "facade",
     hdrs = ["public/pw_sys_io/sys_io.h"],
@@ -44,18 +49,32 @@ pw_cc_library(
 
 pw_cc_library(
     name = "pw_sys_io",
+    hdrs = ["public/pw_sys_io/sys_io.h"],
+    includes = ["public"],
     deps = [
-        ":facade",
-        "@pigweed_config//:pw_sys_io_backend",
+        "//pw_bytes",
+        "//pw_status",
+        "@pigweed//targets:pw_sys_io_backend",
     ],
 )
 
-pw_cc_library(
+alias(
     name = "backend_multiplexer",
-    visibility = ["@pigweed_config//:__pkg__"],
-    deps = select({
-        "//pw_build/constraints/chipset:stm32f429": ["@pigweed//pw_sys_io_baremetal_stm32f429"],
-        "//pw_build/constraints/chipset:lm3s6965evb": ["@pigweed//pw_sys_io_baremetal_lm3s6965evb"],
-        "//conditions:default": ["@pigweed//pw_sys_io_stdio"],
+    actual = select({
+        "//pw_sys_io_arduino:backend": "@pigweed//pw_sys_io_arduino",
+        "//pw_sys_io_baremetal_lm3s6965evb:backend": "@pigweed//pw_sys_io_baremetal_lm3s6965evb",
+        "//pw_sys_io_baremetal_stm32f429:backend": "@pigweed//pw_sys_io_baremetal_stm32f429",
+        "//pw_sys_io_emcraft_sf2:backend": "@pigweed//pw_sys_io_emcraft_sf2",
+        "//pw_sys_io_mcuxpresso:backend": "@pigweed//pw_sys_io_mcuxpresso",
+        "//pw_sys_io_rp2040:backend": "@pigweed//pw_sys_io_rp2040",
+        "//pw_sys_io_stm32cube:backend": "@pigweed//pw_sys_io_stm32cube",
+        "//pw_sys_io_stdio:backend": "@pigweed//pw_sys_io_stdio",
+        "//conditions:default": ":unspecified_backend",
     }),
+    visibility = ["@pigweed//targets:__pkg__"],
+)
+
+host_backend_alias(
+    name = "unspecified_backend",
+    backend = "@pigweed//pw_sys_io_stdio",
 )