diff --git a/CMakeLists.txt b/CMakeLists.txt
index 843b12ac94..2fe8936165 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -79,6 +79,7 @@ add_subdirectory(pw_async EXCLUDE_FROM_ALL)
 add_subdirectory(pw_async_basic EXCLUDE_FROM_ALL)
 add_subdirectory(pw_async2 EXCLUDE_FROM_ALL)
 add_subdirectory(pw_async2_basic EXCLUDE_FROM_ALL)
+add_subdirectory(pw_async2_epoll EXCLUDE_FROM_ALL)
 add_subdirectory(pw_async_fuchsia EXCLUDE_FROM_ALL)
 add_subdirectory(pw_base64 EXCLUDE_FROM_ALL)
 add_subdirectory(pw_blob_store EXCLUDE_FROM_ALL)
@@ -175,6 +176,13 @@ add_subdirectory(third_party/fuzztest EXCLUDE_FROM_ALL)
 add_subdirectory(third_party/googletest EXCLUDE_FROM_ALL)
 add_subdirectory(third_party/boringssl EXCLUDE_FROM_ALL)
 
+add_custom_target(pw_apps)
+
+# pw_system example apps
+add_subdirectory(targets/host_device_simulator EXCLUDE_FROM_ALL)
+add_dependencies(pw_apps pw_system.system_example)
+add_dependencies(pw_apps pw_system.system_async_host_example)
+
 if(CONFIG_ZEPHYR_PIGWEED_MODULE)
   add_subdirectory(zephyr)
   if(CONFIG_PIGWEED_MINIMAL_CPP_STDLIB)
@@ -184,6 +192,5 @@ if(CONFIG_ZEPHYR_PIGWEED_MODULE)
 else()
   add_subdirectory(targets/host EXCLUDE_FROM_ALL)
 
-  add_custom_target(pw_apps)
   add_dependencies(pw_apps pw_hdlc.rpc_example)
 endif()
diff --git a/pw_async2_epoll/CMakeLists.txt b/pw_async2_epoll/CMakeLists.txt
index c8dc2845c7..63ae2dc621 100644
--- a/pw_async2_epoll/CMakeLists.txt
+++ b/pw_async2_epoll/CMakeLists.txt
@@ -14,7 +14,7 @@
 
 include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
 
-pw_add_library(pw_async2_basic.dispatcher_backend STATIC
+pw_add_library(pw_async2_epoll.dispatcher_backend STATIC
   HEADERS
     public_overrides/pw_async2/dispatcher_native.h
   SOURCES
diff --git a/pw_channel/CMakeLists.txt b/pw_channel/CMakeLists.txt
index 0dfe224fd0..1ed0005705 100644
--- a/pw_channel/CMakeLists.txt
+++ b/pw_channel/CMakeLists.txt
@@ -15,7 +15,7 @@
 include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
 include($ENV{PW_ROOT}/pw_async2/backend.cmake)
 
-pw_add_library(pw_channel INTERFACE
+pw_add_library(pw_channel STATIC
   HEADERS
     public/pw_channel/channel.h
   PUBLIC_DEPS
@@ -31,6 +31,8 @@ pw_add_library(pw_channel INTERFACE
     pw_toolchain._sibling_cast
   PUBLIC_INCLUDES
     public
+  SOURCES
+    public/pw_channel/internal/channel_specializations.h
 )
 
 pw_add_test(pw_channel.channel_test
@@ -95,8 +97,11 @@ pw_add_library(pw_channel.epoll_channel STATIC
   PUBLIC_DEPS
     pw_channel
     pw_multibuf.allocator
+    pw_sync.mutex
   PUBLIC_INCLUDES
     public
+  PRIVATE_DEPS
+    pw_log
 )
 
 pw_add_test(pw_channel.epoll_channel_test
diff --git a/pw_file/CMakeLists.txt b/pw_file/CMakeLists.txt
index 671f340560..b6f95bff57 100644
--- a/pw_file/CMakeLists.txt
+++ b/pw_file/CMakeLists.txt
@@ -15,19 +15,22 @@
 include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
 include($ENV{PW_ROOT}/pw_protobuf_compiler/proto.cmake)
 
-pw_add_library(pw_file.flat_file_system INTERFACE
+pw_add_library(pw_file.flat_file_system STATIC
+  HEADERS
+    public/pw_file/flat_file_system.h
   PUBLIC_INCLUDES
     public
   PUBLIC_DEPS
-    pw_file.proto.pwpb
-    pw_file.proto.raw_rpc
     pw_assert
     pw_bytes
+    pw_file.proto.pwpb
+    pw_file.proto.raw_rpc
     pw_log
     pw_result
+    pw_span
     pw_status
-  PRIVATE_DEPS
-    pw_rpc.test_utils
+  SOURCES
+    flat_file_system.cc
 )
 
 pw_proto_library(pw_file.proto
@@ -38,3 +41,18 @@ pw_proto_library(pw_file.proto
   PREFIX
     pw_file
 )
+
+pw_add_test(pw_file.flat_file_system_test
+  SOURCES
+    flat_file_system_test.cc
+  PRIVATE_DEPS
+    pw_bytes
+    pw_file.flat_file_system
+    pw_file.proto.pwpb
+    pw_protobuf
+    pw_rpc.raw.test_method_context
+    pw_status
+  GROUPS
+    modules
+    pw_file
+)
diff --git a/pw_sensor/CMakeLists.txt b/pw_sensor/CMakeLists.txt
index af31913b2b..8191bc1b54 100644
--- a/pw_sensor/CMakeLists.txt
+++ b/pw_sensor/CMakeLists.txt
@@ -51,6 +51,7 @@ pw_add_library(pw_sensor INTERFACE
     pw_tokenizer
 )
 
+# This test does not run on CMake due to missing pw_sensor_library function.
 pw_add_test(pw_sensor.constants_test
   SOURCES
     attributes_test.cc
diff --git a/pw_system/CMakeLists.txt b/pw_system/CMakeLists.txt
index b1544c56be..b1e7f71f14 100644
--- a/pw_system/CMakeLists.txt
+++ b/pw_system/CMakeLists.txt
@@ -14,17 +14,29 @@
 
 include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
 include($ENV{PW_ROOT}/pw_system/backend.cmake)
+include($ENV{PW_ROOT}/pw_protobuf_compiler/proto.cmake)
 
 # WARNING: Many of the dependencies in this file are missing and need to be
 # added/updated. This is provided as a starting point, but currently does not
 # work.
 
-pw_add_library(pw_system.config INTERFACE
-  HEADERS
-    public/pw_system/config.h
-  PUBLIC_INCLUDES
-    public
-)
+if("${pw_cpu_exception.entry_BACKEND}" STREQUAL "")
+  pw_add_library(pw_system.config INTERFACE
+    HEADERS
+      public/pw_system/config.h
+    PUBLIC_INCLUDES
+      public
+    PUBLIC_DEFINES
+      PW_SYSTEM_ENABLE_CRASH_HANDLER=0
+  )
+else()
+  pw_add_library(pw_system.config INTERFACE
+    HEADERS
+      public/pw_system/config.h
+    PUBLIC_INCLUDES
+      public
+  )
+endif()
 
 pw_add_library(pw_system.log STATIC
   PUBLIC_DEPS
@@ -71,6 +83,7 @@ pw_add_facade(pw_system.rpc_server INTERFACE
   PUBLIC_INCLUDES
     public
   PUBLIC_DEPS
+    pw_rpc.server
     pw_system.config
     pw_thread.thread_core
 )
@@ -87,6 +100,7 @@ pw_add_library(pw_system.hdlc_rpc_server STATIC
     pw_system.sys_io_target_io
     pw_thread.thread_core
     pw_trace
+    pw_log
   SOURCES
     hdlc_rpc_server.cc
 )
@@ -169,7 +183,9 @@ pw_add_library(pw_system.trace_service STATIC
     trace_service.cc
 )
 
-pw_add_library(pw_system.io INTERFACE
+pw_add_facade(pw_system.io INTERFACE
+  BACKEND
+    pw_system.io_BACKEND
   HEADERS
     public/pw_system/io.h
   PUBLIC_INCLUDES
@@ -178,6 +194,55 @@ pw_add_library(pw_system.io INTERFACE
     pw_stream
 )
 
+pw_add_facade(pw_system.device_handler INTERFACE
+  BACKEND
+    pw_system.device_handler_BACKEND
+  HEADERS
+    public/pw_system/device_handler.h
+  PUBLIC_INCLUDES
+    public
+  PUBLIC_DEPS
+    pw_snapshot.snapshot_proto.pwpb
+)
+
+pw_add_library(pw_system.unknown_device_handler STATIC
+  SOURCES
+    unknown_device_handler.cc
+  PRIVATE_DEPS
+    pw_system.device_handler.facade
+)
+
+pw_proto_library(pw_system.device_service_proto
+  SOURCES
+    pw_system_protos/device_service.proto
+  INPUTS
+    pw_system_protos/device_service.options
+)
+
+pw_add_library(pw_system.device_service_pwpb STATIC
+  HEADERS
+    public/pw_system/device_service_pwpb.h
+  PUBLIC_INCLUDES
+    public
+  SOURCES
+    device_service_pwpb.cc
+  PUBLIC_DEPS
+    pw_system.device_service_proto.pwpb_rpc
+  PRIVATE_DEPS
+    pw_system.device_handler
+)
+
+pw_add_library(pw_system.device_service STATIC
+  HEADERS
+    public/pw_system/device_service.h
+  PUBLIC_INCLUDES
+    public
+  SOURCES
+    device_service.cc
+  PRIVATE_DEPS
+    pw_system.device_service_pwpb
+)
+
 pw_add_library(pw_system.init STATIC
   HEADERS
     public/pw_system/init.h
@@ -186,17 +251,19 @@ pw_add_library(pw_system.init STATIC
   SOURCES
     init.cc
   PRIVATE_DEPS
+    pw_system.device_service
+    pw_system.file_manager
     pw_system.file_service
     pw_system.log
     pw_system.rpc_server
-    pw_system.target_hooks
+    pw_system.target_hooks.facade
     pw_system.thread_snapshot_service
     pw_system.trace_service
     pw_system.transfer_service
-    pw_system.file_manager
     pw_system.work_queue
-    pw_rpc.pwpb.echo_service
+    pw_metric.global
     pw_metric.metric_service_pwpb
+    pw_rpc.pwpb.echo_service
     pw_thread.thread
     pw_trace
 )
@@ -216,13 +283,24 @@ pw_add_library(pw_system.work_queue STATIC
 
 pw_add_library(pw_system.sys_io_target_io STATIC
   PRIVATE_DEPS
-    pw_system.io
+    pw_system.io.facade
     pw_stream
     pw_stream.sys_io_stream
   SOURCES
     sys_io_target_io.cc
 )
 
+pw_add_library(pw_system.socket_target_io STATIC
+  SOURCES
+    socket_target_io.cc
+  PRIVATE_DEPS
+    pw_assert
+    pw_stream
+    pw_stream.socket_stream
+    pw_system.config
+    pw_system.io.facade
+)
+
 pw_add_facade(pw_system.target_hooks INTERFACE
   BACKEND
     pw_system.target_hooks_BACKEND
@@ -264,13 +342,125 @@ pw_add_library(pw_system.zephyr_target_hooks STATIC
     pw_thread_zephyr.thread
 )
 
-pw_add_library(pw_system.system_example STATIC
-  PRIVATE_DEPS
+add_executable(pw_system.system_example EXCLUDE_FROM_ALL
+  example_user_app_init.cc
+)
+target_link_libraries(pw_system.system_example
+  PRIVATE
     pw_system.init
     pw_system.io
+    pw_system.log
+    pw_system.rpc_server
+    pw_system.work_queue
+    pw_log
+    pw_thread.sleep
+    pw_trace
+    pw_unit_test.rpc_service
     pw_system.target_hooks
-    pw_stream
-    pw_stream.sys_io_stream
+    targets.host_device_simulator.boot
+)
+
+pw_add_library(pw_system.async STATIC
+  HEADERS
+    public/pw_system/system.h
+  PUBLIC_INCLUDES
+    public
   SOURCES
-    example_user_app_init.cc
+    pw_system_private/threads.h
+    system.cc
+    threads.cc
+  PUBLIC_DEPS
+    pw_allocator.allocator
+    pw_async2.dispatcher
+    pw_channel
+    pw_rpc.server
+  PRIVATE_DEPS
+    pw_system.async_packet_io
+    pw_system.file_manager
+    pw_system.file_service
+    pw_system.log
+    pw_system.thread_snapshot_service
+    pw_system.transfer_service
+    pw_system.work_queue
+    pw_allocator.best_fit_block_allocator
+    pw_allocator.synchronized_allocator
+    pw_async2.allocate_task
+    pw_async2.pend_func_task
+    pw_hdlc.router
+    pw_multibuf.simple_allocator
+    pw_rpc.pwpb.echo_service
+    pw_sync.interrupt_spin_lock
+    pw_thread.thread
+)
+
+pw_add_library(pw_system.async_packet_io STATIC
+  HEADERS
+    public/pw_system/internal/async_packet_io.h
+  PUBLIC_INCLUDES
+    public
+  SOURCES
+    async_packet_io.cc
+  PUBLIC_DEPS
+    pw_async2.dispatcher
+    pw_channel.forwarding_channel
+    pw_containers.inline_var_len_entry_queue
+    pw_hdlc.router
+    pw_multibuf.simple_allocator
+    pw_rpc.server
+    pw_sync.lock_annotations
+    pw_sync.mutex
+    pw_sync.thread_notification
+    pw_thread.thread
+    pw_thread.thread_core
+    pw_allocator.allocator
+    pw_channel
+    pw_multibuf
+  PRIVATE_DEPS
+    pw_system.config
+    pw_assert
+    pw_log
+)
+
+if((NOT "${pw_async2.dispatcher_BACKEND}" STREQUAL "") AND
+   (NOT "${CMAKE_SYSTEM_NAME}" STREQUAL "Windows"))
+  # TODO: b/317922402 - Run on Windows when thread detaching is supported.
+  pw_add_test(pw_system.async_packet_io_test
+    SOURCES
+      async_packet_io_test.cc
+    PRIVATE_DEPS
+      pw_system.async_packet_io
+      pw_allocator.testing
+      pw_channel.loopback_channel
+      pw_multibuf.testing
+    GROUPS
+      modules
+      pw_system
+  )
+
+  pw_add_test(pw_system.system_async_test
+    SOURCES
+      system_async_test.cc
+    PRIVATE_DEPS
+      pw_system.async
+      pw_allocator.testing
+      pw_channel.loopback_channel
+      pw_multibuf.testing
+    GROUPS
+      modules
+      pw_system
+  )
+endif()
+
+
+add_executable(pw_system.system_async_host_example EXCLUDE_FROM_ALL
+  example_user_app_init.cc
+)
+target_link_libraries(pw_system.system_async_host_example
+  PRIVATE
+    pw_system.async
+    pw_channel.epoll_channel
+    pw_multibuf.testing
+    pw_trace
+    pw_unit_test.rpc_service
+    targets.host_device_simulator.boot
 )
diff --git a/pw_system/backend.cmake b/pw_system/backend.cmake
index 297eaff6eb..a505bb648e 100644
--- a/pw_system/backend.cmake
+++ b/pw_system/backend.cmake
@@ -20,3 +20,9 @@ pw_add_backend_variable(pw_system.rpc_server_BACKEND)
 
 # The pw_system backend that provides the system target hooks.
 pw_add_backend_variable(pw_system.target_hooks_BACKEND)
+
+pw_add_backend_variable(pw_system.device_handler_BACKEND
+  DEFAULT_BACKEND
+    pw_system.unknown_device_handler
+)
+pw_add_backend_variable(pw_system.io_BACKEND)
diff --git a/pw_thread/CMakeLists.txt b/pw_thread/CMakeLists.txt
index 5b5f44cf58..50a67111ce 100644
--- a/pw_thread/CMakeLists.txt
+++ b/pw_thread/CMakeLists.txt
@@ -134,6 +134,7 @@ pw_add_library(pw_thread.thread_snapshot_service STATIC
   PUBLIC_INCLUDES
     public
   PUBLIC_DEPS
+    pw_log
     pw_protobuf
     pw_rpc.raw.server_api
     pw_span
diff --git a/pw_thread_stl/CMakeLists.txt b/pw_thread_stl/CMakeLists.txt
index e865a2ba1c..70d0650c86 100644
--- a/pw_thread_stl/CMakeLists.txt
+++ b/pw_thread_stl/CMakeLists.txt
@@ -92,6 +92,15 @@ pw_add_library(pw_thread_stl.test_threads STATIC
     pw_thread.thread
 )
 
+pw_add_library(pw_thread_stl.thread_iteration STATIC
+  PRIVATE_DEPS
+    pw_status
+  SOURCES
+    thread_iteration.cc
+  PUBLIC_DEPS
+    pw_thread.thread_iteration.facade
+)
+
 if(("${pw_thread.thread_BACKEND}" STREQUAL "pw_thread_stl.thread") AND
    (NOT "${pw_thread.sleep_BACKEND}" STREQUAL ""))
   pw_add_test(pw_thread_stl.thread_backend_test
diff --git a/pw_toolchain/host_clang/toolchain.cmake b/pw_toolchain/host_clang/toolchain.cmake
index 7e5a065ab3..f9ab9522e6 100644
--- a/pw_toolchain/host_clang/toolchain.cmake
+++ b/pw_toolchain/host_clang/toolchain.cmake
@@ -24,8 +24,10 @@ include($ENV{PW_ROOT}/pw_perf_test/backend.cmake)
 include($ENV{PW_ROOT}/pw_rpc/system_server/backend.cmake)
 include($ENV{PW_ROOT}/pw_sync/backend.cmake)
 include($ENV{PW_ROOT}/pw_sys_io/backend.cmake)
+include($ENV{PW_ROOT}/pw_system/backend.cmake)
 include($ENV{PW_ROOT}/pw_thread/backend.cmake)
 include($ENV{PW_ROOT}/pw_trace/backend.cmake)
+include($ENV{PW_ROOT}/pw_trace_tokenized/backend.cmake)
 
 set(CMAKE_C_COMPILER clang)
 set(CMAKE_CXX_COMPILER clang++)
@@ -37,7 +39,7 @@ pw_set_backend(pw_assert.check pw_assert.print_and_abort_check_backend)
 pw_set_backend(pw_assert.assert pw_assert.print_and_abort_assert_backend)
 
 # Configure backend for async dispatcher facade
-pw_set_backend(pw_async2.dispatcher pw_async2_basic.dispatcher_backend)
+pw_set_backend(pw_async2.dispatcher pw_async2_epoll.dispatcher_backend)
 
 # Configure backend for logging facade.
 pw_set_backend(pw_log pw_log_basic)
@@ -74,9 +76,17 @@ pw_set_backend(pw_thread.yield pw_thread_stl.yield)
 pw_set_backend(pw_thread.sleep pw_thread_stl.sleep)
 pw_set_backend(pw_thread.thread pw_thread_stl.thread)
 pw_set_backend(pw_thread.test_thread_context pw_thread_stl.test_thread_context)
+pw_set_backend(pw_thread.thread_iteration pw_thread_stl.thread_iteration)
 
-# TODO(ewout): Migrate this to match GN's tokenized trace setup.
-pw_set_backend(pw_trace pw_trace.null)
+# Configure backends for pw_system
+pw_set_backend(pw_system.target_hooks pw_system.stl_target_hooks)
+pw_set_backend(pw_system.rpc_server pw_system.hdlc_rpc_server)
+pw_set_backend(pw_system.io pw_system.sys_io_target_io)
+
+# Configure backends for pw_trace
+pw_set_backend(pw_trace pw_trace_tokenized)
+# Maybe this should just be a facade?
+set(pw_trace_tokenizer_time pw_trace_tokenized.host_trace_time CACHE STRING "Tokenizer trace time implementation" FORCE)
 
 if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
     # The CIPD provided Clang/LLVM toolchain must link against the matched
diff --git a/pw_toolchain/host_gcc/toolchain.cmake b/pw_toolchain/host_gcc/toolchain.cmake
index 019c3ae95f..0f39140b61 100644
--- a/pw_toolchain/host_gcc/toolchain.cmake
+++ b/pw_toolchain/host_gcc/toolchain.cmake
@@ -17,14 +17,17 @@
 include(${CMAKE_CURRENT_LIST_DIR}/../../pw_build/pigweed.cmake)
 
 include($ENV{PW_ROOT}/pw_assert/backend.cmake)
+include($ENV{PW_ROOT}/pw_async2/backend.cmake)
 include($ENV{PW_ROOT}/pw_chrono/backend.cmake)
 include($ENV{PW_ROOT}/pw_log/backend.cmake)
 include($ENV{PW_ROOT}/pw_perf_test/backend.cmake)
 include($ENV{PW_ROOT}/pw_rpc/system_server/backend.cmake)
 include($ENV{PW_ROOT}/pw_sync/backend.cmake)
 include($ENV{PW_ROOT}/pw_sys_io/backend.cmake)
+include($ENV{PW_ROOT}/pw_system/backend.cmake)
 include($ENV{PW_ROOT}/pw_thread/backend.cmake)
 include($ENV{PW_ROOT}/pw_trace/backend.cmake)
+include($ENV{PW_ROOT}/pw_trace_tokenized/backend.cmake)
 
 set(CMAKE_C_COMPILER gcc)
 set(CMAKE_CXX_COMPILER g++)
@@ -35,6 +38,9 @@ pw_add_global_compile_options(-std=c++20 LANGUAGES CXX)
 pw_set_backend(pw_assert.check pw_assert.print_and_abort_check_backend)
 pw_set_backend(pw_assert.assert pw_assert.print_and_abort_assert_backend)
 
+# Configure backend for async dispatcher facade
+pw_set_backend(pw_async2.dispatcher pw_async2_epoll.dispatcher_backend)
+
 # Configure backend for logging facade.
 pw_set_backend(pw_log pw_log_basic)
 
@@ -62,16 +68,25 @@ pw_set_backend(pw_chrono.system_clock pw_chrono_stl.system_clock)
 pw_set_backend(pw_chrono.system_timer pw_chrono_stl.system_timer)
 
 # Configure backend for pw_perf_test's facade.
-pw_perf_test(pw_perf_test.timer pw_perf_test.chrono_timer)
+pw_set_backend(pw_perf_test.TIMER_INTERFACE_BACKEND pw_perf_test.chrono_timer)
 
 # Configure backends for pw_thread's facades.
 pw_set_backend(pw_thread.id pw_thread_stl.id)
 pw_set_backend(pw_thread.yield pw_thread_stl.yield)
 pw_set_backend(pw_thread.sleep pw_thread_stl.sleep)
 pw_set_backend(pw_thread.thread pw_thread_stl.thread)
+pw_set_backend(pw_thread.test_thread_context pw_thread_stl.test_thread_context)
+pw_set_backend(pw_thread.thread_iteration pw_thread_stl.thread_iteration)
+
+# Configure backends for pw_system
+pw_set_backend(pw_system.target_hooks pw_system.stl_target_hooks)
+pw_set_backend(pw_system.rpc_server pw_system.hdlc_rpc_server)
+pw_set_backend(pw_system.io pw_system.sys_io_target_io)
 
-# TODO(ewout): Migrate this to match GN's tokenized trace setup.
-pw_set_backend(pw_trace pw_trace.null)
+# Configure backends for pw_trace
+pw_set_backend(pw_trace pw_trace_tokenized)
+# Maybe this should just be a facade?
+set(pw_trace_tokenizer_time pw_trace_tokenized.host_trace_time CACHE STRING "Tokenizer trace time implementation" FORCE)
 
 set(pw_build_WARNINGS pw_build.strict_warnings pw_build.extra_strict_warnings
     CACHE STRING "" FORCE)
diff --git a/pw_trace_tokenized/CMakeLists.txt b/pw_trace_tokenized/CMakeLists.txt
index bc6268f900..7749f9a2d8 100644
--- a/pw_trace_tokenized/CMakeLists.txt
+++ b/pw_trace_tokenized/CMakeLists.txt
@@ -14,6 +14,7 @@
 
 include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
 include($ENV{PW_ROOT}/pw_protobuf_compiler/proto.cmake)
+include($ENV{PW_ROOT}/pw_trace_tokenized/backend.cmake)
 
 pw_add_module_config(pw_trace_tokenized_CONFIG)
 
@@ -26,7 +27,21 @@ pw_add_library(pw_trace_tokenized.config INTERFACE
     ${pw_trace_CONFIG}
 )
 
-pw_add_library(pw_trace_tokenized STATIC
+pw_add_library(pw_trace_tokenized.fake_trace_time STATIC
+  PRIVATE_DEPS
+    pw_trace_tokenized.config
+  SOURCES
+    fake_trace_time.cc
+)
+
+pw_add_library(pw_trace_tokenized.host_trace_time STATIC
+  PRIVATE_DEPS
+    pw_trace_tokenized.config
+  SOURCES
+    host_trace_time.cc
+)
+
+pw_add_library(pw_trace_tokenized.core STATIC
   HEADERS
     public/pw_trace_tokenized/internal/trace_tokenized_internal.h
     public/pw_trace_tokenized/trace_callback.h
@@ -36,34 +51,65 @@ pw_add_library(pw_trace_tokenized STATIC
     public
     public_overrides
   PUBLIC_DEPS
+    pw_log
     pw_span
     pw_status
     pw_tokenizer
-    pw_trace_tokenized.config
   SOURCES
     trace.cc
   PRIVATE_DEPS
+    pw_trace_tokenized.config
     pw_assert
-    pw_log
     pw_ring_buffer
     pw_trace.facade
     pw_varint
+    ${pw_trace_tokenizer_time}
 )
 
+pw_add_library(pw_trace_tokenized INTERFACE
+  PUBLIC_DEPS
+    pw_trace_tokenized.core
+    pw_trace_tokenized.config
+  PUBLIC_INCLUDES
+    public
+    public_overrides
+  PRIVATE_DEPS
+    ${pw_trace_tokenizer_time}
+)
+
+if(("${pw_trace_BACKEND}" STREQUAL "pw_trace_tokenized") AND
+   (NOT "${pw_trace_tokenizer_time}" STREQUAL ""))
+pw_add_test(pw_trace_tokenized.trace_tokenized_test
+  SOURCES
+    trace_test.cc
+  PRIVATE_DEPS
+    pw_trace_tokenized.core
+    pw_trace
+    ${pw_trace_tokenizer_time}
+  GROUPS
+    modules
+    pw_trace_tokenized
+)
+endif()
+
 pw_add_library(pw_trace_tokenized.trace_buffer STATIC
+  HEADERS
+    public/pw_trace_tokenized/trace_buffer.h
+  PUBLIC_INCLUDES
+    public
   SOURCES
     trace_buffer.cc
   PRIVATE_DEPS
-    pw_assert
-    pw_bytes
-    pw_log
+    pw_trace_tokenized.core
   PUBLIC_DEPS
+    pw_bytes
     pw_ring_buffer
-    pw_status
     pw_tokenizer
-    pw_trace_tokenized
     pw_trace_tokenized.config
     pw_varint
+    pw_span
+  PUBLIC_DEFINES
+    PW_TRACE_BUFFER_SIZE_BYTES=${pw_trace_tokenized_BUFFER_SIZE}
 )
 
 pw_proto_library(pw_trace_tokenized.protos
diff --git a/pw_trace_tokenized/backend.cmake b/pw_trace_tokenized/backend.cmake
new file mode 100644
index 0000000000..f69f4b5d6b
--- /dev/null
+++ b/pw_trace_tokenized/backend.cmake
@@ -0,0 +1,24 @@
+# Copyright 2024 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+include_guard(GLOBAL)
+
+include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
+
+set(pw_trace_tokenizer_time ""
+  CACHE STRING
+  "Tokenizer trace time, gets included if provided")
+
+set(pw_trace_tokenized_BUFFER_SIZE "256"
+  CACHE STRING
+  "Trace buffer size in bytes. Set to 0 to disable.")
diff --git a/pw_transfer/CMakeLists.txt b/pw_transfer/CMakeLists.txt
index 9e79c369ae..d626d3483c 100644
--- a/pw_transfer/CMakeLists.txt
+++ b/pw_transfer/CMakeLists.txt
@@ -20,18 +20,27 @@ pw_add_module_config(pw_transfer_CONFIG)
 pw_add_library(pw_transfer.config INTERFACE
   PUBLIC_DEPS
     ${pw_transfer_CONFIG}
+    pw_chrono.system_timer
   HEADERS
     public/pw_transfer/internal/config.h
   PUBLIC_INCLUDES
     public
 )
 
-pw_add_library(pw_transfer INTERFACE
+pw_add_library(pw_transfer STATIC
+  HEADERS
+    public/pw_transfer/transfer.h
+  PUBLIC_INCLUDES
+    public
+  SOURCES
+    transfer.cc
   PUBLIC_DEPS
     pw_assert
+    pw_bytes
     pw_result
     pw_status
     pw_stream
+    pw_sync.mutex
     pw_transfer.core
     pw_transfer.proto.raw_rpc
   PRIVATE_DEPS
@@ -40,34 +49,57 @@ pw_add_library(pw_transfer INTERFACE
     pw_transfer.proto.pwpb
 )
 
-pw_add_library(pw_transfer.client INTERFACE
+pw_add_library(pw_transfer.client STATIC
+  HEADERS
+    public/pw_transfer/client.h
+  PUBLIC_INCLUDES
+    public
+  SOURCES
+    client.cc
   PUBLIC_DEPS
     pw_assert
     pw_function
     pw_stream
-    pw_sync.mutex
     pw_transfer.core
     pw_transfer.proto.raw_rpc
   PRIVATE_DEPS
     pw_log
-    pw_transfer.proto.pwpb
 )
 
-pw_add_library(pw_transfer.core INTERFACE
+pw_add_library(pw_transfer.core STATIC
   PUBLIC_DEPS
     pw_bytes
     pw_chrono.system_clock
     pw_containers.intrusive_list
     pw_result
     pw_rpc.client
+    pw_rpc.raw.client_api
+    pw_rpc.raw.server_api
     pw_status
     pw_stream
     pw_sync.binary_semaphore
+    pw_sync.timed_thread_notification
     pw_thread.thread_core
     pw_transfer.config
+    pw_transfer.proto.pwpb
+  HEADERS
+    public/pw_transfer/internal/chunk.h
+    public/pw_transfer/internal/client_context.h
+    public/pw_transfer/internal/context.h
+    public/pw_transfer/internal/event.h
+    public/pw_transfer/internal/protocol.h
+    public/pw_transfer/internal/server_context.h
+  SOURCES
+    chunk.cc
+    client_context.cc
+    context.cc
+    rate_estimate.cc
+    server_context.cc
+    transfer_thread.cc
   PRIVATE_DEPS
+    pw_log
+    pw_log.rate_limited
     pw_protobuf
-    pw_transfer.proto.pwpb
     pw_varint
 )
 
@@ -77,3 +109,105 @@ pw_proto_library(pw_transfer.proto
   PREFIX
     pw_transfer
 )
+
+pw_add_library(pw_transfer.test_helpers INTERFACE
+  HEADERS
+    pw_transfer_private/chunk_testing.h
+  PUBLIC_DEPS
+    pw_transfer.core
+    pw_containers
+)
+
+pw_add_library(pw_transfer.atomic_file_transfer_handler STATIC
+  PUBLIC_INCLUDES
+    public
+  HEADERS
+    public/pw_transfer/atomic_file_transfer_handler.h
+  SOURCES
+    atomic_file_transfer_handler.cc
+  PUBLIC_DEPS
+    pw_transfer.core
+    pw_stream.std_file_stream
+  PRIVATE_DEPS
+    pw_transfer.atomic_file_transfer_handler_internal
+    pw_log
+)
+
+pw_add_library(pw_transfer.atomic_file_transfer_handler_internal INTERFACE
+  HEADERS
+    pw_transfer_private/filename_generator.h
+)
+
+if("${pw_thread.thread_BACKEND}" STREQUAL "pw_thread_stl.thread")
+  pw_add_test(pw_transfer.client_test
+    SOURCES
+      client_test.cc
+    PRIVATE_DEPS
+      pw_rpc.raw.client_testing
+      pw_rpc.test_helpers
+      pw_thread.sleep
+      pw_thread.thread
+      pw_transfer.client
+      pw_transfer.test_helpers
+    GROUPS
+      modules
+      pw_transfer
+  )
+endif()
+
+if(("${pw_thread.thread_BACKEND}" STREQUAL "pw_thread_stl.thread") AND
+   (${pw_unit_test_BACKEND} STREQUAL "pw_unit_test.light"))
+  pw_add_test(pw_transfer.transfer_thread_test
+    SOURCES
+      transfer_thread_test.cc
+    PRIVATE_DEPS
+      pw_transfer.proto.raw_rpc
+      pw_transfer.core
+      pw_transfer
+      pw_transfer.test_helpers
+      pw_rpc.test_helpers
+      pw_rpc.raw.client_testing
+      pw_rpc.raw.test_method_context
+      pw_thread.thread
+    GROUPS
+      modules
+      pw_transfer
+  )
+endif()
+
+if(("${pw_thread.thread_BACKEND}" STREQUAL "pw_thread_stl.thread") AND
+   (NOT "${CMAKE_SYSTEM_NAME}" STREQUAL "Windows"))
+  pw_add_test(pw_transfer.chunk_test
+    SOURCES
+      chunk_test.cc
+    PRIVATE_DEPS
+      pw_transfer.core
+    GROUPS
+      modules
+      pw_transfer
+  )
+
+  pw_add_test(pw_transfer.handler_test
+    SOURCES
+      handler_test.cc
+    PRIVATE_DEPS
+      pw_transfer
+    GROUPS
+      modules
+      pw_transfer
+  )
+
+  pw_add_test(pw_transfer.atomic_file_transfer_handler_test
+    SOURCES
+      atomic_file_transfer_handler_test.cc
+    PRIVATE_DEPS
+      pw_transfer.atomic_file_transfer_handler
+      pw_transfer.atomic_file_transfer_handler_internal
+      pw_transfer
+      pw_random
+      pw_string
+    GROUPS
+      modules
+      pw_transfer
+  )
+endif()
diff --git a/pw_unit_test/CMakeLists.txt b/pw_unit_test/CMakeLists.txt
index 57acd59693..abb3c0baa9 100644
--- a/pw_unit_test/CMakeLists.txt
+++ b/pw_unit_test/CMakeLists.txt
@@ -13,6 +13,9 @@
 # the License.
 
 include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
+include($ENV{PW_ROOT}/pw_protobuf_compiler/proto.cmake)
+
+include($ENV{PW_ROOT}/pw_unit_test/backend.cmake)
 
 pw_add_module_config(pw_unit_test_CONFIG)
 
@@ -58,8 +61,10 @@ pw_add_library(pw_unit_test.light STATIC
     pw_bytes.alignment
     pw_polyfill
     pw_preprocessor
-    pw_string
+    pw_string.builder
     pw_unit_test.config
+  PRIVATE_DEPS
+    pw_assert
   PUBLIC_INCLUDES
     light_public_overrides
     public
@@ -227,3 +232,53 @@ pw_add_test(pw_unit_test.test_record_event_handler_test
   GROUPS
     pw_unit_test
 )
+
+pw_proto_library(pw_unit_test.unit_test_proto
+  SOURCES
+    pw_unit_test_proto/unit_test.proto
+)
+
+if("${pw_unit_test_BACKEND}" STREQUAL "pw_unit_test.light")
+  pw_add_library(pw_unit_test.rpc_service STATIC
+    PUBLIC_DEPS
+      pw_unit_test.config
+      pw_unit_test.event_handler
+      pw_unit_test
+      pw_unit_test.unit_test_proto.pwpb
+      pw_unit_test.unit_test_proto.raw_rpc
+      pw_containers.vector
+    PRIVATE_DEPS
+      pw_log
+    PUBLIC_INCLUDES
+      public
+      rpc_light_public
+    HEADERS
+      public/pw_unit_test/unit_test_service.h
+      rpc_light_public/pw_unit_test/internal/rpc_event_handler.h
+    SOURCES
+      unit_test_service.cc
+      rpc_light_event_handler.cc
+  )
+else()
+  pw_add_library(pw_unit_test.rpc_service STATIC
+    PUBLIC_DEPS
+      pw_unit_test.config
+      pw_unit_test.event_handler
+      pw_unit_test
+      pw_unit_test.unit_test_proto.pwpb
+      pw_unit_test.unit_test_proto.raw_rpc
+      pw_containers.vector
+    PRIVATE_DEPS
+      pw_log
+    PUBLIC_INCLUDES
+      public
+      rpc_gtest_public
+    HEADERS
+      public/pw_unit_test/unit_test_service.h
+      rpc_light_public/pw_unit_test/internal/rpc_event_handler.h
+      rpc_gtest_public/pw_unit_test/internal/rpc_event_handler.h
+    SOURCES
+      unit_test_service.cc
+      rpc_gtest_event_handler.cc
+  )
+endif()
diff --git a/pw_unit_test/backend.cmake b/pw_unit_test/backend.cmake
new file mode 100644
index 0000000000..9859ed18db
--- /dev/null
+++ b/pw_unit_test/backend.cmake
@@ -0,0 +1,24 @@
+# Copyright 2024 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+include_guard(GLOBAL)
+
+include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
+
+set(pw_unit_test_BACKEND ="pw_unit_test.light"
+  CACHE STRING
+  "The unit test framework implementation. Defaults to pw_unit_test.light, which implements a subset of GoogleTest safe to run on device.")
+
+set(pw_unit_test_MAIN "pw_unit_test.simple_printing_main"
+  CACHE STRING
+  "Implementation of a main function for ``pw_test`` unit test binaries. Must be set to an appropriate target for the pw_unit_test backend.")
diff --git a/targets/host_device_simulator/CMakeLists.txt b/targets/host_device_simulator/CMakeLists.txt
new file mode 100644
index 0000000000..89ba006888
--- /dev/null
+++ b/targets/host_device_simulator/CMakeLists.txt
@@ -0,0 +1,24 @@
+# Copyright 2024 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
+
+pw_add_library(targets.host_device_simulator.boot STATIC
+  PRIVATE_DEPS
+    pw_log
+    pw_system.init
+    pw_thread.sleep
+  SOURCES
+    boot.cc
+)