diff --git a/src/common/pico_base/BUILD.bazel b/src/common/pico_base/BUILD.bazel
index dd8cf99..e4aa2f7 100644
--- a/src/common/pico_base/BUILD.bazel
+++ b/src/common/pico_base/BUILD.bazel
@@ -61,6 +61,7 @@
         "//src/common/pico_sync:__pkg__",
         "//src/common/pico_time:__pkg__",
         "//src/common/pico_util:__pkg__",
+        "//src/host/hardware_timer:__pkg__",
         "//src/host/pico_platform:__pkg__",
         "//src/rp2_common/boot_stage2:__pkg__",
         "//src/rp2_common/hardware_claim:__pkg__",
@@ -94,10 +95,16 @@
         # via an intermediate.
         ":pico_platform",
         ":pico_base_interface",
-        "//src/rp2_common/cmsis:cmsis_core",
-        "//src/rp2_common/boot_stage2",
-        "//src/rp2_common/pico_bootrom",
-        "//src/rp2_common/pico_runtime",
-        "//src/rp2_common/pico_standard_link",
-    ],
+    ] + select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/boot_stage2",
+            "//src/rp2_common/cmsis:cmsis_core",
+            "//src/rp2_common/pico_bootrom",
+            "//src/rp2_common/pico_runtime",
+            "//src/rp2_common/pico_standard_link",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/pico_platform",
+        ],
+    }),
 )
diff --git a/src/common/pico_bit_ops/BUILD.bazel b/src/common/pico_bit_ops/BUILD.bazel
index 3a81933..d414d35 100644
--- a/src/common/pico_bit_ops/BUILD.bazel
+++ b/src/common/pico_bit_ops/BUILD.bazel
@@ -8,6 +8,7 @@
     hdrs = ["include/pico/bit_ops.h"],
     includes = ["include"],
     visibility = [
+        "//src/host/pico_bit_ops:__pkg__",
         "//src/rp2_common/pico_bit_ops:__pkg__",
     ],
     deps = [
@@ -19,13 +20,10 @@
     name = "pico_bit_ops",
     hdrs = ["include/pico/bit_ops.h"],
     includes = ["include"],
-    # TODO: Add `select()` for host redirections.
-    target_compatible_with = select({
-        "//bazel/constraint:rp2": [],
-        "//conditions:default": ["@platforms//:incompatible"],
-    }),
     deps = [
         "//src/common/pico_base",
-        "//src/rp2_common/pico_bit_ops",
-    ],
+    ] + select({
+        "//bazel/constraint:host": ["//src/host/pico_bit_ops"],
+        "//bazel/constraint:rp2": ["//src/rp2_common/pico_bit_ops"],
+    }),
 )
diff --git a/src/common/pico_stdlib/BUILD.bazel b/src/common/pico_stdlib/BUILD.bazel
index 0e34e67..0feb8e4 100644
--- a/src/common/pico_stdlib/BUILD.bazel
+++ b/src/common/pico_stdlib/BUILD.bazel
@@ -6,39 +6,46 @@
     name = "pico_stdlib_interface",
     hdrs = ["include/pico/stdlib.h"],
     includes = ["include"],
-    # TODO: Add `select()` for host redirections.
-    target_compatible_with = select({
-        "//bazel/constraint:rp2": [],
-        "//conditions:default": ["@platforms//:incompatible"],
-    }),
     visibility = [
+        "//src/host/pico_stdio:__pkg__",
+        "//src/host/pico_stdlib:__pkg__",
         "//src/rp2_common/pico_stdlib:__pkg__",
         "//src/rp2_common/tinyusb:__pkg__",
     ],
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
-        "//src/rp2_common/hardware_gpio",
-        "//src/rp2_common/hardware_uart",
-        "//src/rp2_common/pico_stdio",
-    ],
+    ] + select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/hardware_gpio",
+            "//src/rp2_common/hardware_uart",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/hardware_gpio",
+            "//src/host/hardware_uart",
+        ],
+    }),
 )
 
 cc_library(
     name = "pico_stdlib",
     hdrs = ["include/pico/stdlib.h"],
     includes = ["include"],
-    # TODO: Add `select()` for host redirections.
-    target_compatible_with = select({
-        "//bazel/constraint:rp2": [],
-        "//conditions:default": ["@platforms//:incompatible"],
-    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
-        "//src/rp2_common/hardware_gpio",
-        "//src/rp2_common/hardware_uart",
-        "//src/rp2_common/pico_stdio",
-        "//src/rp2_common/pico_stdlib",
-    ],
+    ] + select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/hardware_gpio",
+            "//src/rp2_common/hardware_uart",
+            "//src/rp2_common/pico_stdio",
+            "//src/rp2_common/pico_stdlib",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/hardware_gpio",
+            "//src/host/hardware_uart",
+            "//src/host/pico_stdio",
+            "//src/host/pico_stdlib",
+        ],
+    }),
 )
diff --git a/src/common/pico_sync/BUILD.bazel b/src/common/pico_sync/BUILD.bazel
index 68042a9..b963c3c 100644
--- a/src/common/pico_sync/BUILD.bazel
+++ b/src/common/pico_sync/BUILD.bazel
@@ -16,14 +16,15 @@
         "include/pico/sync.h",
     ],
     includes = ["include"],
-    # TODO: Add `select()` for host redirections.
-    target_compatible_with = select({
-        "//bazel/constraint:rp2": [],
-        "//conditions:default": ["@platforms//:incompatible"],
-    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_time:pico_time_headers",
-        "//src/rp2_common/hardware_sync",
-    ],
+    ] + select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/hardware_sync",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/hardware_sync",
+        ],
+    }),
 )
diff --git a/src/common/pico_time/BUILD.bazel b/src/common/pico_time/BUILD.bazel
index b32dc5b..716c65b 100644
--- a/src/common/pico_time/BUILD.bazel
+++ b/src/common/pico_time/BUILD.bazel
@@ -14,9 +14,14 @@
         "//src/common/pico_sync:__pkg__",
         "//src/rp2_common/tinyusb:__pkg__",
     ],
-    deps = [
-        "//src/rp2_common/hardware_timer:hardware_timer_headers",
-    ],
+    deps = select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/hardware_timer:hardware_timer_headers",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/hardware_timer:hardware_timer_headers",
+        ],
+    }),
 )
 
 cc_library(
@@ -30,15 +35,16 @@
         "include/pico/timeout_helper.h",
     ],
     includes = ["include"],
-    # TODO: Add `select()` for host redirections.
-    target_compatible_with = select({
-        "//bazel/constraint:rp2": [],
-        "//conditions:default": ["@platforms//:incompatible"],
-    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_sync",
         "//src/common/pico_util",
-        "//src/rp2_common/hardware_timer",
-    ],
+    ] + select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/hardware_timer",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/hardware_timer",
+        ],
+    }),
 )
diff --git a/src/common/pico_util/BUILD.bazel b/src/common/pico_util/BUILD.bazel
index 00d7b23..856d7b5 100644
--- a/src/common/pico_util/BUILD.bazel
+++ b/src/common/pico_util/BUILD.bazel
@@ -13,14 +13,15 @@
         "include/pico/util/queue.h",
     ],
     includes = ["include"],
-    # TODO: Add `select()` for host redirections.
-    target_compatible_with = select({
-        "//bazel/constraint:rp2": [],
-        "//conditions:default": ["@platforms//:incompatible"],
-    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_sync",
-        "//src/rp2_common/hardware_sync",
-    ],
+    ] + select({
+        "//bazel/constraint:rp2": [
+            "//src/rp2_common/hardware_sync",
+        ],
+        "//bazel/constraint:host": [
+            "//src/host/hardware_sync",
+        ],
+    }),
 )
diff --git a/src/host/hardware_divider/BUILD.bazel b/src/host/hardware_divider/BUILD.bazel
new file mode 100644
index 0000000..3548f1b
--- /dev/null
+++ b/src/host/hardware_divider/BUILD.bazel
@@ -0,0 +1,10 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "hardware_divider",
+    srcs = ["divider.c"],
+    hdrs = ["include/hardware/divider.h"],
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    deps = ["//src/common/pico_base"],
+)
diff --git a/src/host/hardware_gpio/BUILD.bazel b/src/host/hardware_gpio/BUILD.bazel
new file mode 100644
index 0000000..816ebb4
--- /dev/null
+++ b/src/host/hardware_gpio/BUILD.bazel
@@ -0,0 +1,10 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "hardware_gpio",
+    srcs = ["gpio.c"],
+    hdrs = ["include/hardware/gpio.h"],
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    deps = ["//src/common/pico_base"],
+)
diff --git a/src/host/hardware_sync/BUILD.bazel b/src/host/hardware_sync/BUILD.bazel
new file mode 100644
index 0000000..f218d36
--- /dev/null
+++ b/src/host/hardware_sync/BUILD.bazel
@@ -0,0 +1,11 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "hardware_sync",
+    srcs = ["sync_core0_only.c"],
+    hdrs = ["include/hardware/sync.h"],
+    implementation_deps = ["//src/host/pico_platform:platform_defs"],
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    deps = ["//src/common/pico_base"],
+)
diff --git a/src/host/hardware_timer/BUILD.bazel b/src/host/hardware_timer/BUILD.bazel
new file mode 100644
index 0000000..af37e2f
--- /dev/null
+++ b/src/host/hardware_timer/BUILD.bazel
@@ -0,0 +1,30 @@
+package(default_visibility = ["//visibility:public"])
+
+_DEFINES = [
+    "PICO_HARDWARE_TIMER_RESOLUTION_US=1000",
+    # TODO: This seems to be the default, make configurable eventually.
+    "PICO_TIME_DEFAULT_ALARM_POOL_DISABLED=1",
+]
+
+# This exists to break a dependency cycle between
+# this library and //src/common/pico_time.
+# Application code should always use :hardware_timer instead.
+cc_library(
+    name = "hardware_timer_headers",
+    hdrs = ["include/hardware/timer.h"],
+    defines = _DEFINES,
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    visibility = ["//src/common/pico_time:__pkg__"],
+    deps = ["//src/common/pico_base:pico_base_interface"],
+)
+
+cc_library(
+    name = "hardware_timer",
+    srcs = ["timer.c"],
+    hdrs = ["include/hardware/timer.h"],
+    defines = _DEFINES,
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    deps = ["//src/common/pico_base"],
+)
diff --git a/src/host/hardware_uart/BUILD.bazel b/src/host/hardware_uart/BUILD.bazel
new file mode 100644
index 0000000..5288d14
--- /dev/null
+++ b/src/host/hardware_uart/BUILD.bazel
@@ -0,0 +1,10 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "hardware_uart",
+    srcs = ["uart.c"],
+    hdrs = ["include/hardware/uart.h"],
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    deps = ["//src/common/pico_base"],
+)
diff --git a/src/host/pico_bit_ops/BUILD.bazel b/src/host/pico_bit_ops/BUILD.bazel
new file mode 100644
index 0000000..a0e7dc4
--- /dev/null
+++ b/src/host/pico_bit_ops/BUILD.bazel
@@ -0,0 +1,8 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "pico_bit_ops",
+    srcs = ["bit_ops.c"],
+    implementation_deps = ["//src/common/pico_bit_ops:pico_bit_ops_headers"],
+    target_compatible_with = ["//bazel/constraint:host"],
+)
diff --git a/src/host/pico_divider/BUILD.bazel b/src/host/pico_divider/BUILD.bazel
new file mode 100644
index 0000000..e82785f
--- /dev/null
+++ b/src/host/pico_divider/BUILD.bazel
@@ -0,0 +1,8 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "pico_divider",
+    srcs = ["divider.c"],
+    implementation_deps = ["//src/common/pico_divider"],
+    target_compatible_with = ["//bazel/constraint:host"],
+)
diff --git a/src/host/pico_multicore/BUILD.bazel b/src/host/pico_multicore/BUILD.bazel
new file mode 100644
index 0000000..61b1092
--- /dev/null
+++ b/src/host/pico_multicore/BUILD.bazel
@@ -0,0 +1,9 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "pico_multicore",
+    hdrs = ["include/pico/multicore.h"],
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+    deps = ["//src/common/pico_base"],
+)
diff --git a/src/host/pico_platform/BUILD.bazel b/src/host/pico_platform/BUILD.bazel
index 2cad9cd..d89fd3a 100644
--- a/src/host/pico_platform/BUILD.bazel
+++ b/src/host/pico_platform/BUILD.bazel
@@ -6,6 +6,7 @@
         "include/hardware/platform_defs.h",
     ],
     includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
 )
 
 cc_library(
@@ -15,6 +16,7 @@
         "include/pico/platform.h",
     ],
     includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
     deps = [
         ":platform_defs",
         "//src/common/pico_base:pico_base_interface",
diff --git a/src/host/pico_printf/BUILD.bazel b/src/host/pico_printf/BUILD.bazel
new file mode 100644
index 0000000..b6a4bb7
--- /dev/null
+++ b/src/host/pico_printf/BUILD.bazel
@@ -0,0 +1,6 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "pico_printf",
+    target_compatible_with = ["//bazel/constraint:host"],
+)
diff --git a/src/host/pico_stdio/BUILD.bazel b/src/host/pico_stdio/BUILD.bazel
new file mode 100644
index 0000000..abdc993
--- /dev/null
+++ b/src/host/pico_stdio/BUILD.bazel
@@ -0,0 +1,13 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "pico_stdio",
+    srcs = ["stdio.c"],
+    hdrs = ["include/pico/stdio.h"],
+    implementation_deps = [
+        "//src/common/pico_stdlib:pico_stdlib_interface",
+        "//src/host/hardware_uart",
+    ],
+    includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:host"],
+)
diff --git a/src/host/pico_stdlib/BUILD.bazel b/src/host/pico_stdlib/BUILD.bazel
new file mode 100644
index 0000000..245f693
--- /dev/null
+++ b/src/host/pico_stdlib/BUILD.bazel
@@ -0,0 +1,11 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "pico_stdlib",
+    srcs = ["stdlib.c"],
+    implementation_deps = [
+        "//src/common/pico_stdlib:pico_stdlib_interface",
+        "//src/host/pico_stdio",
+    ],
+    target_compatible_with = ["//bazel/constraint:host"],
+)
diff --git a/src/rp2040/hardware_regs/BUILD.bazel b/src/rp2040/hardware_regs/BUILD.bazel
index 6bd0081..d2793e6 100644
--- a/src/rp2040/hardware_regs/BUILD.bazel
+++ b/src/rp2040/hardware_regs/BUILD.bazel
@@ -9,6 +9,7 @@
         "include/hardware/platform_defs.h",
     ],
     includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:rp2040"],
 )
 
 cc_library(
@@ -50,4 +51,5 @@
         "include/hardware/regs/xosc.h",
     ],
     includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:rp2040"],
 )
diff --git a/src/rp2040/hardware_structs/BUILD.bazel b/src/rp2040/hardware_structs/BUILD.bazel
index 692334c..a4ddb7b 100644
--- a/src/rp2040/hardware_structs/BUILD.bazel
+++ b/src/rp2040/hardware_structs/BUILD.bazel
@@ -40,4 +40,5 @@
         "include/hardware/structs/xosc.h",
     ],
     includes = ["include"],
+    target_compatible_with = ["//bazel/constraint:rp2040"],
 )
diff --git a/src/rp2_common/boot_stage2/BUILD.bazel b/src/rp2_common/boot_stage2/BUILD.bazel
index df6a041..6cff436 100644
--- a/src/rp2_common/boot_stage2/BUILD.bazel
+++ b/src/rp2_common/boot_stage2/BUILD.bazel
@@ -23,6 +23,10 @@
         "asminclude",
         "include",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = ["//src/rp2_common/pico_standard_link:__pkg__"],
 )
 
@@ -45,6 +49,10 @@
     # rp2040_bootloader_binary transition forcibly clobbers --custom_malloc.
     malloc = ":no_malloc",
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "boot_stage2.ld",
         ":config",
@@ -63,6 +71,10 @@
     name = "boot_stage2_bin",
     src = ":boot_stage2_elf",
     out = "boot_stage2.bin",
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
 
 # WORKAROUND: Python rules always require a .py extension.
@@ -70,11 +82,13 @@
     name = "copy_tool_to_py",
     src = "pad_checksum",
     out = "pad_checksum_tool.py",
+    target_compatible_with = ["//bazel/constraint:host"],
 )
 
 py_binary(
     name = "pad_checksum_tool",
     srcs = ["pad_checksum_tool.py"],
+    target_compatible_with = ["//bazel/constraint:host"],
 )
 
 run_binary(
@@ -86,12 +100,20 @@
         "$(location boot_stage2_bin)",
         "$(location boot_stage2.S)",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     tool = ":pad_checksum_tool",
 )
 
 cc_library(
     name = "boot_stage2",
     srcs = [":boot_stage2_padded"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = ["//visibility:public"],
     # This isn't referenced as a symbol, so alwayslink is required to ensure
     # it doesn't get dropped before the linker script can find it.
diff --git a/src/rp2_common/cmsis/BUILD.bazel b/src/rp2_common/cmsis/BUILD.bazel
index 24cf5df..173c683 100644
--- a/src/rp2_common/cmsis/BUILD.bazel
+++ b/src/rp2_common/cmsis/BUILD.bazel
@@ -4,6 +4,10 @@
     name = "rename_exceptions",
     hdrs = ["include/cmsis/rename_exceptions.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
 
 cc_library(
@@ -28,6 +32,10 @@
         "stub/CMSIS/Core/Include",
         "stub/CMSIS/Device/RaspberryPi/RP2040/Include",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/rp2_common/hardware_clocks",
     ],
diff --git a/src/rp2_common/hardware_adc/BUILD.bazel b/src/rp2_common/hardware_adc/BUILD.bazel
index 29dfd09..9d46bf4 100644
--- a/src/rp2_common/hardware_adc/BUILD.bazel
+++ b/src/rp2_common/hardware_adc/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["adc.c"],
     hdrs = ["include/hardware/adc.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_gpio",
diff --git a/src/rp2_common/hardware_base/BUILD.bazel b/src/rp2_common/hardware_base/BUILD.bazel
index ebf54b9..cc2b1a8 100644
--- a/src/rp2_common/hardware_base/BUILD.bazel
+++ b/src/rp2_common/hardware_base/BUILD.bazel
@@ -4,4 +4,8 @@
     name = "hardware_base",
     hdrs = ["include/hardware/address_mapped.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
diff --git a/src/rp2_common/hardware_claim/BUILD.bazel b/src/rp2_common/hardware_claim/BUILD.bazel
index b9875ca..1daa428 100644
--- a/src/rp2_common/hardware_claim/BUILD.bazel
+++ b/src/rp2_common/hardware_claim/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["claim.c"],
     hdrs = ["include/hardware/claim.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_base:pico_platform",
diff --git a/src/rp2_common/hardware_clocks/BUILD.bazel b/src/rp2_common/hardware_clocks/BUILD.bazel
index 7152804..76f52a9 100644
--- a/src/rp2_common/hardware_clocks/BUILD.bazel
+++ b/src/rp2_common/hardware_clocks/BUILD.bazel
@@ -7,6 +7,10 @@
     name = "hardware_clocks_headers",
     hdrs = ["include/hardware/clocks.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = [
         "//src/rp2_common/hardware_pll:__pkg__",
         "//src/rp2_common/hardware_xosc:__pkg__",
@@ -22,6 +26,10 @@
     srcs = ["clocks.c"],
     hdrs = ["include/hardware/clocks.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/rp2_common/hardware_gpio",
diff --git a/src/rp2_common/hardware_divider/BUILD.bazel b/src/rp2_common/hardware_divider/BUILD.bazel
index 0b3dc9c..1ef2bd9 100644
--- a/src/rp2_common/hardware_divider/BUILD.bazel
+++ b/src/rp2_common/hardware_divider/BUILD.bazel
@@ -8,6 +8,10 @@
         "include/hardware/divider_helper.S",
     ],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_platform",
diff --git a/src/rp2_common/hardware_dma/BUILD.bazel b/src/rp2_common/hardware_dma/BUILD.bazel
index fceabfb..001f967 100644
--- a/src/rp2_common/hardware_dma/BUILD.bazel
+++ b/src/rp2_common/hardware_dma/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["dma.c"],
     hdrs = ["include/hardware/dma.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_claim",
diff --git a/src/rp2_common/hardware_exception/BUILD.bazel b/src/rp2_common/hardware_exception/BUILD.bazel
index 72b4c41..5c1b2d0 100644
--- a/src/rp2_common/hardware_exception/BUILD.bazel
+++ b/src/rp2_common/hardware_exception/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["exception.c"],
     hdrs = ["include/hardware/exception.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_base",
diff --git a/src/rp2_common/hardware_flash/BUILD.bazel b/src/rp2_common/hardware_flash/BUILD.bazel
index ee79e6f..ae3d381 100644
--- a/src/rp2_common/hardware_flash/BUILD.bazel
+++ b/src/rp2_common/hardware_flash/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["flash.c"],
     hdrs = ["include/hardware/flash.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_bootrom",
diff --git a/src/rp2_common/hardware_gpio/BUILD.bazel b/src/rp2_common/hardware_gpio/BUILD.bazel
index 5d035eb..63c5e76 100644
--- a/src/rp2_common/hardware_gpio/BUILD.bazel
+++ b/src/rp2_common/hardware_gpio/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["gpio.c"],
     hdrs = ["include/hardware/gpio.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_binary_info",
diff --git a/src/rp2_common/hardware_i2c/BUILD.bazel b/src/rp2_common/hardware_i2c/BUILD.bazel
index cd9110f..71329c3 100644
--- a/src/rp2_common/hardware_i2c/BUILD.bazel
+++ b/src/rp2_common/hardware_i2c/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["i2c.c"],
     hdrs = ["include/hardware/i2c.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
diff --git a/src/rp2_common/hardware_interp/BUILD.bazel b/src/rp2_common/hardware_interp/BUILD.bazel
index fa8106f..c4d2087 100644
--- a/src/rp2_common/hardware_interp/BUILD.bazel
+++ b/src/rp2_common/hardware_interp/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["interp.c"],
     hdrs = ["include/hardware/interp.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_claim",
diff --git a/src/rp2_common/hardware_irq/BUILD.bazel b/src/rp2_common/hardware_irq/BUILD.bazel
index 0e929c9..0484790 100644
--- a/src/rp2_common/hardware_irq/BUILD.bazel
+++ b/src/rp2_common/hardware_irq/BUILD.bazel
@@ -8,6 +8,10 @@
     ],
     hdrs = ["include/hardware/irq.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_sync",
diff --git a/src/rp2_common/hardware_pio/BUILD.bazel b/src/rp2_common/hardware_pio/BUILD.bazel
index 0cf474d..e15b6ad 100644
--- a/src/rp2_common/hardware_pio/BUILD.bazel
+++ b/src/rp2_common/hardware_pio/BUILD.bazel
@@ -8,6 +8,10 @@
         "include/hardware/pio_instructions.h",
     ],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_base",
diff --git a/src/rp2_common/hardware_pll/BUILD.bazel b/src/rp2_common/hardware_pll/BUILD.bazel
index ea0199b..f8a7b50 100644
--- a/src/rp2_common/hardware_pll/BUILD.bazel
+++ b/src/rp2_common/hardware_pll/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["pll.c"],
     hdrs = ["include/hardware/pll.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_base:pico_platform",
diff --git a/src/rp2_common/hardware_pwm/BUILD.bazel b/src/rp2_common/hardware_pwm/BUILD.bazel
index 2b9b4d1..b90f55b 100644
--- a/src/rp2_common/hardware_pwm/BUILD.bazel
+++ b/src/rp2_common/hardware_pwm/BUILD.bazel
@@ -4,6 +4,10 @@
     name = "hardware_pwm",
     hdrs = ["include/hardware/pwm.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_platform:hardware_regs",
diff --git a/src/rp2_common/hardware_resets/BUILD.bazel b/src/rp2_common/hardware_resets/BUILD.bazel
index 294ed23..d3f1bfd 100644
--- a/src/rp2_common/hardware_resets/BUILD.bazel
+++ b/src/rp2_common/hardware_resets/BUILD.bazel
@@ -4,6 +4,10 @@
     name = "hardware_resets",
     hdrs = ["include/hardware/resets.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/rp2_common/pico_platform:hardware_structs",
diff --git a/src/rp2_common/hardware_rtc/BUILD.bazel b/src/rp2_common/hardware_rtc/BUILD.bazel
index 7992511..7adddaf 100644
--- a/src/rp2_common/hardware_rtc/BUILD.bazel
+++ b/src/rp2_common/hardware_rtc/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["rtc.c"],
     hdrs = ["include/hardware/rtc.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_clocks",
diff --git a/src/rp2_common/hardware_spi/BUILD.bazel b/src/rp2_common/hardware_spi/BUILD.bazel
index e9bccc9..55849c5 100644
--- a/src/rp2_common/hardware_spi/BUILD.bazel
+++ b/src/rp2_common/hardware_spi/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["spi.c"],
     hdrs = ["include/hardware/spi.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_clocks",
diff --git a/src/rp2_common/hardware_sync/BUILD.bazel b/src/rp2_common/hardware_sync/BUILD.bazel
index 3805642..38d744a 100644
--- a/src/rp2_common/hardware_sync/BUILD.bazel
+++ b/src/rp2_common/hardware_sync/BUILD.bazel
@@ -7,6 +7,10 @@
     name = "hardware_sync_headers",
     hdrs = ["include/hardware/sync.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = ["//src/rp2_common/hardware_claim:__pkg__"],
     deps = [
         "//src/common/pico_base:pico_base_interface",
@@ -20,6 +24,10 @@
     srcs = ["sync.c"],
     hdrs = ["include/hardware/sync.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/rp2_common/hardware_base",
diff --git a/src/rp2_common/hardware_timer/BUILD.bazel b/src/rp2_common/hardware_timer/BUILD.bazel
index b97bcde..2f305ca 100644
--- a/src/rp2_common/hardware_timer/BUILD.bazel
+++ b/src/rp2_common/hardware_timer/BUILD.bazel
@@ -7,6 +7,10 @@
     name = "hardware_timer_headers",
     hdrs = ["include/hardware/timer.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = ["//src/common/pico_time:__pkg__"],
     deps = [
         "//src/common/pico_base:pico_base_interface",
@@ -19,6 +23,10 @@
     srcs = ["timer.c"],
     hdrs = ["include/hardware/timer.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/rp2_common/hardware_claim",
diff --git a/src/rp2_common/hardware_uart/BUILD.bazel b/src/rp2_common/hardware_uart/BUILD.bazel
index a329df3..1792ee0 100644
--- a/src/rp2_common/hardware_uart/BUILD.bazel
+++ b/src/rp2_common/hardware_uart/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["uart.c"],
     hdrs = ["include/hardware/uart.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_base",
diff --git a/src/rp2_common/hardware_vreg/BUILD.bazel b/src/rp2_common/hardware_vreg/BUILD.bazel
index 0a90697..0f20163 100644
--- a/src/rp2_common/hardware_vreg/BUILD.bazel
+++ b/src/rp2_common/hardware_vreg/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["vreg.c"],
     hdrs = ["include/hardware/vreg.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_platform:hardware_structs",
diff --git a/src/rp2_common/hardware_watchdog/BUILD.bazel b/src/rp2_common/hardware_watchdog/BUILD.bazel
index fad2f97..1a6defb 100644
--- a/src/rp2_common/hardware_watchdog/BUILD.bazel
+++ b/src/rp2_common/hardware_watchdog/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["watchdog.c"],
     hdrs = ["include/hardware/watchdog.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_base:pico_platform",
diff --git a/src/rp2_common/hardware_xosc/BUILD.bazel b/src/rp2_common/hardware_xosc/BUILD.bazel
index 2ed2201..4eed17d 100644
--- a/src/rp2_common/hardware_xosc/BUILD.bazel
+++ b/src/rp2_common/hardware_xosc/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["xosc.c"],
     hdrs = ["include/hardware/xosc.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_base:pico_platform",
diff --git a/src/rp2_common/pico_async_context/BUILD.bazel b/src/rp2_common/pico_async_context/BUILD.bazel
index 577d1c8..1554a0b 100644
--- a/src/rp2_common/pico_async_context/BUILD.bazel
+++ b/src/rp2_common/pico_async_context/BUILD.bazel
@@ -21,6 +21,10 @@
     #    semphr.h
     #    timers.h
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_sync",
diff --git a/src/rp2_common/pico_bit_ops/BUILD.bazel b/src/rp2_common/pico_bit_ops/BUILD.bazel
index 35322a8..089130d 100644
--- a/src/rp2_common/pico_bit_ops/BUILD.bazel
+++ b/src/rp2_common/pico_bit_ops/BUILD.bazel
@@ -16,6 +16,10 @@
         "-Wl,--wrap=__clzsi2",
         "-Wl,--wrap=__clzll",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_bit_ops:pico_bit_ops_headers",
         "//src/rp2_common/pico_bootrom",
diff --git a/src/rp2_common/pico_bootrom/BUILD.bazel b/src/rp2_common/pico_bootrom/BUILD.bazel
index b31378c..cca3e43 100644
--- a/src/rp2_common/pico_bootrom/BUILD.bazel
+++ b/src/rp2_common/pico_bootrom/BUILD.bazel
@@ -8,6 +8,10 @@
         "include/pico/bootrom/sf_table.h",
     ],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_base:pico_platform",
diff --git a/src/rp2_common/pico_bootsel_via_double_reset/BUILD.bazel b/src/rp2_common/pico_bootsel_via_double_reset/BUILD.bazel
index 8e85b70..a766bcb 100644
--- a/src/rp2_common/pico_bootsel_via_double_reset/BUILD.bazel
+++ b/src/rp2_common/pico_bootsel_via_double_reset/BUILD.bazel
@@ -3,6 +3,10 @@
 cc_library(
     name = "pico_bootsel_via_double_reset",
     srcs = ["pico_bootsel_via_double_reset.c"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_binary_info",
diff --git a/src/rp2_common/pico_btstack/BUILD.bazel b/src/rp2_common/pico_btstack/BUILD.bazel
index c3afa3e..dd715a8 100644
--- a/src/rp2_common/pico_btstack/BUILD.bazel
+++ b/src/rp2_common/pico_btstack/BUILD.bazel
@@ -18,6 +18,10 @@
     #     btstack_stdin.h
     #     hal_flash_bank.h
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_sync",
diff --git a/src/rp2_common/pico_cxx_options/BUILD.bazel b/src/rp2_common/pico_cxx_options/BUILD.bazel
index 6fb8268..80a46a2 100644
--- a/src/rp2_common/pico_cxx_options/BUILD.bazel
+++ b/src/rp2_common/pico_cxx_options/BUILD.bazel
@@ -2,4 +2,8 @@
 
 cc_library(
     name = "pico_cxx_options",
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
diff --git a/src/rp2_common/pico_cyw43_arch/BUILD.bazel b/src/rp2_common/pico_cyw43_arch/BUILD.bazel
index 9ce4516..d64db32 100644
--- a/src/rp2_common/pico_cyw43_arch/BUILD.bazel
+++ b/src/rp2_common/pico_cyw43_arch/BUILD.bazel
@@ -21,6 +21,10 @@
     #     cyw43_ll.h
     #     cyw43_stats.h
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_async_context",
diff --git a/src/rp2_common/pico_cyw43_driver/BUILD.bazel b/src/rp2_common/pico_cyw43_driver/BUILD.bazel
index 1d2fa13..5d2f861 100644
--- a/src/rp2_common/pico_cyw43_driver/BUILD.bazel
+++ b/src/rp2_common/pico_cyw43_driver/BUILD.bazel
@@ -35,6 +35,10 @@
     #     hci_dump_segger_rtt_stdout.h
     #     hci_transport.h
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
diff --git a/src/rp2_common/pico_divider/BUILD.bazel b/src/rp2_common/pico_divider/BUILD.bazel
index f35f225..a2f6ef0 100644
--- a/src/rp2_common/pico_divider/BUILD.bazel
+++ b/src/rp2_common/pico_divider/BUILD.bazel
@@ -11,6 +11,10 @@
         "-Wl,--wrap=__aeabi_uidivmod",
         "-Wl,--wrap=__aeabi_uldivmod",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/rp2_common/hardware_divider",
         "//src/rp2_common/pico_platform",
diff --git a/src/rp2_common/pico_double/BUILD.bazel b/src/rp2_common/pico_double/BUILD.bazel
index f52e78b..200b15a 100644
--- a/src/rp2_common/pico_double/BUILD.bazel
+++ b/src/rp2_common/pico_double/BUILD.bazel
@@ -73,6 +73,10 @@
         "-Wl,--wrap=log1p",
         "-Wl,--wrap=fma",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_divider",
diff --git a/src/rp2_common/pico_fix/BUILD.bazel b/src/rp2_common/pico_fix/BUILD.bazel
index a1b4b2e..6173312 100644
--- a/src/rp2_common/pico_fix/BUILD.bazel
+++ b/src/rp2_common/pico_fix/BUILD.bazel
@@ -2,4 +2,8 @@
 
 cc_library(
     name = "pico_fix",
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
diff --git a/src/rp2_common/pico_fix/rp2040_usb_device_enumeration/BUILD.bazel b/src/rp2_common/pico_fix/rp2040_usb_device_enumeration/BUILD.bazel
index 7b1406c..c40711f 100644
--- a/src/rp2_common/pico_fix/rp2040_usb_device_enumeration/BUILD.bazel
+++ b/src/rp2_common/pico_fix/rp2040_usb_device_enumeration/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["rp2040_usb_device_enumeration.c"],
     hdrs = ["include/pico/fix/rp2040_usb_device_enumeration.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
diff --git a/src/rp2_common/pico_flash/BUILD.bazel b/src/rp2_common/pico_flash/BUILD.bazel
index d9aac18..0745b0e 100644
--- a/src/rp2_common/pico_flash/BUILD.bazel
+++ b/src/rp2_common/pico_flash/BUILD.bazel
@@ -9,6 +9,10 @@
     #     FreeRTOS.h
     #     task.h
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
diff --git a/src/rp2_common/pico_float/BUILD.bazel b/src/rp2_common/pico_float/BUILD.bazel
index c3cef5e..799b23b 100644
--- a/src/rp2_common/pico_float/BUILD.bazel
+++ b/src/rp2_common/pico_float/BUILD.bazel
@@ -73,6 +73,10 @@
         "-Wl,--wrap=log1pf",
         "-Wl,--wrap=fmaf",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_divider",
diff --git a/src/rp2_common/pico_i2c_slave/BUILD.bazel b/src/rp2_common/pico_i2c_slave/BUILD.bazel
index 36e0b9b..bd9aaa9 100644
--- a/src/rp2_common/pico_i2c_slave/BUILD.bazel
+++ b/src/rp2_common/pico_i2c_slave/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["i2c_slave.c"],
     hdrs = ["include/pico/i2c_slave.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/rp2_common/hardware_i2c",
         "//src/rp2_common/hardware_irq",
diff --git a/src/rp2_common/pico_int64_ops/BUILD.bazel b/src/rp2_common/pico_int64_ops/BUILD.bazel
index 6311103..7c62226 100644
--- a/src/rp2_common/pico_int64_ops/BUILD.bazel
+++ b/src/rp2_common/pico_int64_ops/BUILD.bazel
@@ -6,6 +6,10 @@
     hdrs = ["include/pico/int64_ops.h"],
     includes = ["include"],
     linkopts = ["-Wl,--wrap=__aeabi_lmul"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_platform",
diff --git a/src/rp2_common/pico_lwip/BUILD.bazel b/src/rp2_common/pico_lwip/BUILD.bazel
index 76799a5..bbafc09 100644
--- a/src/rp2_common/pico_lwip/BUILD.bazel
+++ b/src/rp2_common/pico_lwip/BUILD.bazel
@@ -18,6 +18,10 @@
     #     lwip/timeouts.h
     #     semphr.h
     tags = ["manual"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
diff --git a/src/rp2_common/pico_malloc/BUILD.bazel b/src/rp2_common/pico_malloc/BUILD.bazel
index 7aa6bae..411a497 100644
--- a/src/rp2_common/pico_malloc/BUILD.bazel
+++ b/src/rp2_common/pico_malloc/BUILD.bazel
@@ -11,6 +11,10 @@
         "-Wl,--wrap=realloc",
         "-Wl,--wrap=free",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_sync",
diff --git a/src/rp2_common/pico_mbedtls/BUILD.bazel b/src/rp2_common/pico_mbedtls/BUILD.bazel
index 8f9a64b..af8f9c6 100644
--- a/src/rp2_common/pico_mbedtls/BUILD.bazel
+++ b/src/rp2_common/pico_mbedtls/BUILD.bazel
@@ -3,6 +3,10 @@
 cc_library(
     name = "pico_mbedtls",
     srcs = ["pico_mbedtls.c"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/rp2_common/pico_platform",
         "//src/rp2_common/pico_rand",
diff --git a/src/rp2_common/pico_mem_ops/BUILD.bazel b/src/rp2_common/pico_mem_ops/BUILD.bazel
index 7d1c965..0c6aa6f 100644
--- a/src/rp2_common/pico_mem_ops/BUILD.bazel
+++ b/src/rp2_common/pico_mem_ops/BUILD.bazel
@@ -18,6 +18,10 @@
         "-Wl,--wrap=__aeabi_memcpy8",
         "-Wl,--wrap=__aeabi_memset8",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/pico_bootrom",
diff --git a/src/rp2_common/pico_multicore/BUILD.bazel b/src/rp2_common/pico_multicore/BUILD.bazel
index 220edd4..35961b7 100644
--- a/src/rp2_common/pico_multicore/BUILD.bazel
+++ b/src/rp2_common/pico_multicore/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["multicore.c"],
     hdrs = ["include/pico/multicore.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_sync",
diff --git a/src/rp2_common/pico_platform/BUILD.bazel b/src/rp2_common/pico_platform/BUILD.bazel
index 0655b41..72c61c8 100644
--- a/src/rp2_common/pico_platform/BUILD.bazel
+++ b/src/rp2_common/pico_platform/BUILD.bazel
@@ -5,6 +5,10 @@
     actual = select({
         "//bazel/constraint:rp2040": "//src/rp2040/hardware_regs:platform_defs",
     }),
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
 
 alias(
@@ -12,6 +16,10 @@
     actual = select({
         "//bazel/constraint:rp2040": "//src/rp2040/hardware_regs:hardware_regs",
     }),
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
 
 alias(
@@ -19,6 +27,10 @@
     actual = select({
         "//bazel/constraint:rp2040": "//src/rp2040/hardware_structs:hardware_structs",
     }),
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
 
 cc_library(
@@ -29,6 +41,10 @@
         "include/pico/platform.h",
     ],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         ":hardware_regs",
         ":platform_defs",
diff --git a/src/rp2_common/pico_printf/BUILD.bazel b/src/rp2_common/pico_printf/BUILD.bazel
index d289845..056f091 100644
--- a/src/rp2_common/pico_printf/BUILD.bazel
+++ b/src/rp2_common/pico_printf/BUILD.bazel
@@ -12,6 +12,10 @@
         "-Wl,--wrap=snprintf",
         "-Wl,--wrap=vsnprintf",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/rp2_common/pico_bootrom",
diff --git a/src/rp2_common/pico_rand/BUILD.bazel b/src/rp2_common/pico_rand/BUILD.bazel
index 3ef576c..7630da5 100644
--- a/src/rp2_common/pico_rand/BUILD.bazel
+++ b/src/rp2_common/pico_rand/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["rand.c"],
     hdrs = ["include/pico/rand.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_time",
diff --git a/src/rp2_common/pico_runtime/BUILD.bazel b/src/rp2_common/pico_runtime/BUILD.bazel
index f3f9bff..4dcbf0e 100644
--- a/src/rp2_common/pico_runtime/BUILD.bazel
+++ b/src/rp2_common/pico_runtime/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["runtime.c"],
     hdrs = ["include/pico/runtime.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base:pico_base_interface",
         "//src/common/pico_sync",
diff --git a/src/rp2_common/pico_standard_link/BUILD.bazel b/src/rp2_common/pico_standard_link/BUILD.bazel
index bfc1376..46b94d9 100644
--- a/src/rp2_common/pico_standard_link/BUILD.bazel
+++ b/src/rp2_common/pico_standard_link/BUILD.bazel
@@ -11,6 +11,10 @@
     linkopts = [
         "-T$(location memmap_default.ld)",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "memmap_default.ld",
         "//src/common/pico_base:pico_base_interface",
diff --git a/src/rp2_common/pico_stdio/BUILD.bazel b/src/rp2_common/pico_stdio/BUILD.bazel
index d380041..c6ba06a 100644
--- a/src/rp2_common/pico_stdio/BUILD.bazel
+++ b/src/rp2_common/pico_stdio/BUILD.bazel
@@ -10,6 +10,10 @@
         "include/pico/stdio/driver.h",
     ],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = [
         "//src/rp2_common/pico_stdio_semihosting:__pkg__",
         "//src/rp2_common/pico_stdio_uart:__pkg__",
@@ -33,6 +37,10 @@
         "-Wl,--wrap=putchar",
         "-Wl,--wrap=getchar",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_sync",
diff --git a/src/rp2_common/pico_stdio_semihosting/BUILD.bazel b/src/rp2_common/pico_stdio_semihosting/BUILD.bazel
index 5ce2a69..0cadf78 100644
--- a/src/rp2_common/pico_stdio_semihosting/BUILD.bazel
+++ b/src/rp2_common/pico_stdio_semihosting/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["stdio_semihosting.c"],
     hdrs = ["include/pico/stdio_semihosting.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_binary_info",
         "//src/rp2_common/pico_stdio:pico_stdio_headers",
diff --git a/src/rp2_common/pico_stdio_uart/BUILD.bazel b/src/rp2_common/pico_stdio_uart/BUILD.bazel
index 3ca9968..9aced45 100644
--- a/src/rp2_common/pico_stdio_uart/BUILD.bazel
+++ b/src/rp2_common/pico_stdio_uart/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["stdio_uart.c"],
     hdrs = ["include/pico/stdio_uart.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_binary_info",
         "//src/rp2_common/hardware_gpio",
diff --git a/src/rp2_common/pico_stdio_usb/BUILD.bazel b/src/rp2_common/pico_stdio_usb/BUILD.bazel
index 58c3cdb..bb414f5 100644
--- a/src/rp2_common/pico_stdio_usb/BUILD.bazel
+++ b/src/rp2_common/pico_stdio_usb/BUILD.bazel
@@ -1,5 +1,6 @@
 package(default_visibility = ["//visibility:public"])
 
+# Picotool requires this, so it should work on host as well as rp2.
 cc_library(
     name = "reset_interface_headers",
     hdrs = ["include/pico/stdio_usb/reset_interface.h"],
@@ -11,12 +12,20 @@
     name = "tusb_config",
     hdrs = ["include/tusb_config.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
 )
 
 cc_library(
     name = "pico_stdio_usb_headers",
     hdrs = ["include/pico/stdio_usb.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     visibility = [
         ":__pkg__",
         "//src/rp2_common/tinyusb:__pkg__",
@@ -30,7 +39,12 @@
         "stdio_usb.c",
         "stdio_usb_descriptors.c",
     ],
-    target_compatible_with = ["//bazel/constraint:stdio_usb"],
+    target_compatible_with = [
+        "//bazel/constraint:stdio_usb",
+    ] + select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         ":pico_stdio_usb_headers",
         ":reset_interface_headers",
diff --git a/src/rp2_common/pico_stdlib/BUILD.bazel b/src/rp2_common/pico_stdlib/BUILD.bazel
index 53b01e1..ef7603d 100644
--- a/src/rp2_common/pico_stdlib/BUILD.bazel
+++ b/src/rp2_common/pico_stdlib/BUILD.bazel
@@ -3,6 +3,10 @@
 cc_library(
     name = "pico_stdlib",
     srcs = ["stdlib.c"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_binary_info",
         "//src/common/pico_stdlib:pico_stdlib_interface",
diff --git a/src/rp2_common/pico_unique_id/BUILD.bazel b/src/rp2_common/pico_unique_id/BUILD.bazel
index 7db977e..6c087ea 100644
--- a/src/rp2_common/pico_unique_id/BUILD.bazel
+++ b/src/rp2_common/pico_unique_id/BUILD.bazel
@@ -5,6 +5,10 @@
     srcs = ["unique_id.c"],
     hdrs = ["include/pico/unique_id.h"],
     includes = ["include"],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/rp2_common/hardware_flash",
diff --git a/src/rp2_common/tinyusb/BUILD.bazel b/src/rp2_common/tinyusb/BUILD.bazel
index 0c395a7..3373652 100644
--- a/src/rp2_common/tinyusb/BUILD.bazel
+++ b/src/rp2_common/tinyusb/BUILD.bazel
@@ -7,6 +7,10 @@
         "CFG_TUSB_MCU=OPT_MCU_RP2040",
         "CFG_TUSB_OS=OPT_OS_PICO",
     ],
+    target_compatible_with = select({
+        "//bazel/constraint:rp2": [],
+        "//conditions:default": ["@platforms//:incompatible"],
+    }),
     deps = [
         "//src/common/pico_base",
         "//src/common/pico_binary_info",