36 files changed, 123 insertions, 123 deletions
diff --git a/BUILD.gn b/BUILD.gn
index 738f08750..c63a20bfe 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -43,7 +43,7 @@ group("host_tools") {
 group("pw_facades") {
   deps = [
     "$dir_pw_cpu_exception",
-    "$dir_pw_dumb_io",
+    "$dir_pw_sys_io",
   ]
 }
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c9e6b7d06..3631ad956 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,8 +25,6 @@ add_subdirectory(pw_checksum)
 add_subdirectory(pw_containers)
 add_subdirectory(pw_cpu_exception)
 add_subdirectory(pw_cpu_exception_armv7m)
-add_subdirectory(pw_dumb_io)
-add_subdirectory(pw_dumb_io_stdio)
 add_subdirectory(pw_kvs)
 add_subdirectory(pw_log)
 add_subdirectory(pw_log_basic)
@@ -36,6 +34,8 @@ add_subdirectory(pw_preprocessor)
 add_subdirectory(pw_span)
 add_subdirectory(pw_status)
 add_subdirectory(pw_string)
+add_subdirectory(pw_sys_io)
+add_subdirectory(pw_sys_io_stdio)
 add_subdirectory(pw_tokenizer)
 add_subdirectory(pw_unit_test)
 add_subdirectory(pw_varint)
diff --git a/docs/BUILD.gn b/docs/BUILD.gn
index 8d5b7c8ed..5bc0f00b8 100644
--- a/docs/BUILD.gn
+++ b/docs/BUILD.gn
@@ -46,9 +46,6 @@ pw_doc_gen("docs") {
     "$dir_pw_cpu_exception_armv7m:docs",
     "$dir_pw_docgen:docs",
     "$dir_pw_doctor:docs",
-    "$dir_pw_dumb_io:docs",
-    "$dir_pw_dumb_io_baremetal_stm32f429:docs",
-    "$dir_pw_dumb_io_stdio:docs",
     "$dir_pw_log:docs",
     "$dir_pw_minimal_cpp_stdlib:docs",
     "$dir_pw_module:docs",
@@ -60,6 +57,9 @@ pw_doc_gen("docs") {
     "$dir_pw_span:docs",
     "$dir_pw_status:docs",
     "$dir_pw_string:docs",
+    "$dir_pw_sys_io:docs",
+    "$dir_pw_sys_io_baremetal_stm32f429:docs",
+    "$dir_pw_sys_io_stdio:docs",
     "$dir_pw_target_runner:docs",
     "$dir_pw_tokenizer:docs",
   ]
diff --git a/modules.gni b/modules.gni
index 6138f24c5..ddc253fde 100644
--- a/modules.gni
+++ b/modules.gni
@@ -28,10 +28,6 @@ dir_pw_cpu_exception = "$dir_pigweed/pw_cpu_exception"
 dir_pw_cpu_exception_armv7m = "$dir_pigweed/pw_cpu_exception_armv7m"
 dir_pw_docgen = "$dir_pigweed/pw_docgen"
 dir_pw_doctor = "$dir_pigweed/pw_doctor"
-dir_pw_dumb_io = "$dir_pigweed/pw_dumb_io"
-dir_pw_dumb_io_baremetal_stm32f429 =
-    "$dir_pigweed/pw_dumb_io_baremetal_stm32f429"
-dir_pw_dumb_io_stdio = "$dir_pigweed/pw_dumb_io_stdio"
 dir_pw_kvs = "$dir_pigweed/pw_kvs"
 dir_pw_log = "$dir_pigweed/pw_log"
 dir_pw_log_basic = "$dir_pigweed/pw_log_basic"
@@ -45,6 +41,9 @@ dir_pw_protobuf_compiler = "$dir_pigweed/pw_protobuf_compiler"
 dir_pw_span = "$dir_pigweed/pw_span"
 dir_pw_status = "$dir_pigweed/pw_status"
 dir_pw_string = "$dir_pigweed/pw_string"
+dir_pw_sys_io = "$dir_pigweed/pw_sys_io"
+dir_pw_sys_io_baremetal_stm32f429 = "$dir_pigweed/pw_sys_io_baremetal_stm32f429"
+dir_pw_sys_io_stdio = "$dir_pigweed/pw_sys_io_stdio"
 dir_pw_target_runner = "$dir_pigweed/pw_target_runner"
 dir_pw_tokenizer = "$dir_pigweed/pw_tokenizer"
 dir_pw_toolchain = "$dir_pigweed/pw_toolchain"
diff --git a/pw_assert_basic/BUILD b/pw_assert_basic/BUILD
index 6a04d08fc..418de2442 100644
--- a/pw_assert_basic/BUILD
+++ b/pw_assert_basic/BUILD
@@ -35,8 +35,8 @@ pw_cc_library(
         "public_overrides",
     ],
     deps = [
-        "//pw_dumb_io",
         "//pw_assert:facade",
         "//pw_string",
+        "//pw_sys_io",
     ],
 )
diff --git a/pw_assert_basic/BUILD.gn b/pw_assert_basic/BUILD.gn
index dab76066f..9b39a97f8 100644
--- a/pw_assert_basic/BUILD.gn
+++ b/pw_assert_basic/BUILD.gn
@@ -36,9 +36,9 @@ source_set("core") {
   public_configs = [ ":default_config" ]
   deps = [
     "$dir_pw_assert:facade",
-    "$dir_pw_dumb_io",
     "$dir_pw_preprocessor",
     "$dir_pw_string",
+    "$dir_pw_sys_io",
   ]
   public = [ "public/pw_assert_basic/assert_basic.h" ]
   sources = public + [ "assert_basic.cc" ]
diff --git a/pw_assert_basic/CMakeLists.txt b/pw_assert_basic/CMakeLists.txt
index 432e5f92b..7e6c46aef 100644
--- a/pw_assert_basic/CMakeLists.txt
+++ b/pw_assert_basic/CMakeLists.txt
@@ -16,9 +16,9 @@ pw_auto_add_simple_module(pw_assert_basic
   IMPLEMENTS_FACADE
     pw_assert
   PRIVATE_DEPS
-    pw_dumb_io
     pw_preprocessor
     pw_string
+    pw_sys_io
 )
 
 target_include_directories(pw_assert_basic PUBLIC public_overrides)
diff --git a/pw_assert_basic/assert_basic.cc b/pw_assert_basic/assert_basic.cc
index b6abdb101..3046ba636 100644
--- a/pw_assert_basic/assert_basic.cc
+++ b/pw_assert_basic/assert_basic.cc
@@ -21,9 +21,9 @@
 
 #include <cstring>
 
-#include "pw_dumb_io/dumb_io.h"
 #include "pw_preprocessor/util.h"
 #include "pw_string/string_builder.h"
+#include "pw_sys_io/sys_io.h"
 
 // TODO(pwbug/17): Expose these through the config system.
 #define PW_ASSERT_BASIC_SHOW_BANNER 1
@@ -73,7 +73,7 @@ static const char* kCrashBanner[] = {
     " ",
 };
 
-using pw::dumb_io::WriteLine;
+using pw::sys_io::WriteLine;
 
 typedef pw::StringBuffer<150> Buffer;
 
@@ -104,7 +104,7 @@ extern "C" void pw_Crash(const char* file_name,
     va_start(args, message);
     buffer.FormatVaList(message, args);
     va_end(args);
-    pw::dumb_io::WriteLine(buffer.view());
+    WriteLine(buffer.view());
   }
 
   WriteLine("");
diff --git a/pw_boot_armv7m/BUILD b/pw_boot_armv7m/BUILD
index 0c7862720..0980c0a20 100644
--- a/pw_boot_armv7m/BUILD
+++ b/pw_boot_armv7m/BUILD
@@ -17,7 +17,7 @@ package(default_visibility = ["//visibility:public"])
 licenses(["notice"])  # Apache License 2.0
 
 filegroup(
-    name = "pw_dumb_io_baremetal_stm32f429",
+    name = "pw_boot_armv7m",
     srcs = [
         "core_init.c",
         "public/pw_boot_armv7m/boot.h",
diff --git a/pw_cpu_exception_armv7m/BUILD.gn b/pw_cpu_exception_armv7m/BUILD.gn
index d627ab7f0..a23a39629 100644
--- a/pw_cpu_exception_armv7m/BUILD.gn
+++ b/pw_cpu_exception_armv7m/BUILD.gn
@@ -27,8 +27,8 @@ if (dir_pw_cpu_exception_backend == dir_pw_cpu_exception_armv7m) {
     public_configs = [ ":default_config" ]
     deps = [
       "$dir_pw_cpu_exception:facade",
-      "$dir_pw_dumb_io:default_putget_bytes",
       "$dir_pw_preprocessor",
+      "$dir_pw_sys_io:default_putget_bytes",
     ]
     public = [ "public/pw_cpu_exception_armv7m/cpu_state.h" ]
     sources = [
diff --git a/pw_log_basic/BUILD b/pw_log_basic/BUILD
index fd9105df6..ad7ac0719 100644
--- a/pw_log_basic/BUILD
+++ b/pw_log_basic/BUILD
@@ -35,8 +35,8 @@ pw_cc_library(
         "public_overrides",
     ],
     deps = [
-        "//pw_dumb_io",
         "//pw_log:facade",
         "//pw_string",
+        "//pw_sys_io",
     ],
 )
diff --git a/pw_log_basic/BUILD.gn b/pw_log_basic/BUILD.gn
index 2b895ace6..0efa82dd1 100644
--- a/pw_log_basic/BUILD.gn
+++ b/pw_log_basic/BUILD.gn
@@ -35,10 +35,10 @@ if (dir_pw_log_backend == dir_pw_log_basic) {
 source_set("pw_log_basic_core") {
   public_configs = [ ":default_config" ]
   deps = [
-    "$dir_pw_dumb_io",
     "$dir_pw_log:facade",
     "$dir_pw_preprocessor",
     "$dir_pw_string",
+    "$dir_pw_sys_io",
   ]
   public = [ "public/pw_log_basic/log_basic.h" ]
   sources = public + [ "log_basic.cc" ]
diff --git a/pw_log_basic/CMakeLists.txt b/pw_log_basic/CMakeLists.txt
index c85276d13..5c66fe041 100644
--- a/pw_log_basic/CMakeLists.txt
+++ b/pw_log_basic/CMakeLists.txt
@@ -16,8 +16,8 @@ pw_auto_add_simple_module(pw_log_basic
   IMPLEMENTS_FACADE
     pw_log
   PRIVATE_DEPS
-    pw_dumb_io
     pw_string
+    pw_sys_io
 )
 
 target_include_directories(pw_log_basic PUBLIC public_overrides)
diff --git a/pw_log_basic/log_basic.cc b/pw_log_basic/log_basic.cc
index c586830a8..e67d6d134 100644
--- a/pw_log_basic/log_basic.cc
+++ b/pw_log_basic/log_basic.cc
@@ -18,9 +18,9 @@
 
 #include <cstring>
 
-#include "pw_dumb_io/dumb_io.h"
 #include "pw_log/levels.h"
 #include "pw_string/string_builder.h"
+#include "pw_sys_io/sys_io.h"
 
 // ANSI color constants to control the terminal. Not Windows compatible.
 // clang-format off
@@ -148,5 +148,5 @@ extern "C" void pw_Log(int level,
   va_end(args);
 
   // All done; flush the log.
-  pw::dumb_io::WriteLine(buffer.view());
+  pw::sys_io::WriteLine(buffer.view());
 }
diff --git a/pw_dumb_io/BUILD b/pw_sys_io/BUILD
index a25a8451f..11e8201c6 100644
--- a/pw_dumb_io/BUILD
+++ b/pw_sys_io/BUILD
@@ -23,7 +23,7 @@ licenses(["notice"])
 
 pw_cc_library(
     name = "facade",
-    hdrs = ["public/pw_dumb_io/dumb_io.h"],
+    hdrs = ["public/pw_sys_io/sys_io.h"],
     includes = ["public"],
     deps = [
         "//pw_span",
@@ -33,7 +33,7 @@ pw_cc_library(
 
 pw_cc_library(
     name = "default_putget_bytes",
-    srcs = ["dumb_io.cc"],
+    srcs = ["sys_io.cc"],
     deps = [
         ":facade",
         "//pw_span",
@@ -42,14 +42,14 @@ pw_cc_library(
 )
 
 pw_cc_library(
-    name = "pw_dumb_io",
-    hdrs = ["public/pw_dumb_io/dumb_io.h"],
+    name = "pw_sys_io",
+    hdrs = ["public/pw_sys_io/sys_io.h"],
     deps = [
         ":facade",
-        # For now, hard-code to depend on stdio until bazel build is updated
-        # to support multiple target configurations.
-        "//pw_dumb_io_stdio",
         "//pw_span",
         "//pw_status",
+        # For now, hard-code to depend on stdio until bazel build is updated
+        # to support multiple target configurations.
+        "//pw_sys_io_stdio",
     ],
 )
diff --git a/pw_dumb_io/BUILD.gn b/pw_sys_io/BUILD.gn
index b451afa04..0c48cf65d 100644
--- a/pw_dumb_io/BUILD.gn
+++ b/pw_sys_io/BUILD.gn
@@ -19,19 +19,19 @@ config("default_config") {
   include_dirs = [ "public" ]
 }
 
-pw_facade("pw_dumb_io") {
-  backend = dir_pw_dumb_io_backend
+pw_facade("pw_sys_io") {
+  backend = dir_pw_sys_io_backend
   public_configs = [ ":default_config" ]
   public_deps = [
     "$dir_pw_span",
     "$dir_pw_status",
   ]
-  public = [ "public/pw_dumb_io/dumb_io.h" ]
+  public = [ "public/pw_sys_io/sys_io.h" ]
 }
 
 source_set("default_putget_bytes") {
   deps = [ ":facade" ]
-  sources = [ "dumb_io.cc" ]
+  sources = [ "sys_io.cc" ]
 }
 
 pw_doc_group("docs") {
diff --git a/pw_dumb_io/CMakeLists.txt b/pw_sys_io/CMakeLists.txt
index 182890430..7ca3860d9 100644
--- a/pw_dumb_io/CMakeLists.txt
+++ b/pw_sys_io/CMakeLists.txt
@@ -12,9 +12,9 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
-pw_add_facade(pw_dumb_io
+pw_add_facade(pw_sys_io
   SOURCES
-    dumb_io.cc
+    sys_io.cc
   PUBLIC_DEPS
     pw_span
     pw_status
diff --git a/pw_dumb_io/docs.rst b/pw_sys_io/docs.rst
index a431f202e..38b5ef78f 100644
--- a/pw_dumb_io/docs.rst
+++ b/pw_sys_io/docs.rst
@@ -1,12 +1,12 @@
-.. _chapter-pw-dumb-io:
+.. _chapter-pw-sys-io:
 
 .. default-domain:: cpp
 
 .. highlight:: sh
 
-----------
-pw_dumb_io
-----------
+---------
+pw_sys_io
+---------
 This module defines a simple and unoptimized interface for byte-by-byte
 input/output. This can be done over a logging system, stdio, UART, via a
 photodiode and modulated kazoo, or basically any way to get data in and out
@@ -34,16 +34,17 @@ Setup
 =====
 This module requires relatively minimal setup:
 
-  1. Chose a ``pw_dumb_io`` backend, or write one yourself.
-  2. If using GN build, Specify the ``dir_pw_dumb_io_backend`` GN global
-     variable to point to your ``pw_dumb_io`` backend.
+  1. Chose a ``pw_sys_io`` backend, or write one yourself.
+  2. If using GN build, Specify the ``dir_pw_sys_io_backend`` GN global
+     variable to point to your ``pw_sys_io`` backend.
 
 Module usage
 ============
-See backend docs for how to interact with the underlying dumb io implementation.
+See backend docs for how to interact with the underlying system I/O
+implementation.
 
 Dependencies
 ============
-  * pw_dumb_io_backend
+  * pw_sys_io_backend
   * pw_span
   * pw_status
diff --git a/pw_dumb_io/public/pw_dumb_io/dumb_io.h b/pw_sys_io/public/pw_sys_io/sys_io.h
index 8f7ce70a8..3010de1ff 100644
--- a/pw_dumb_io/public/pw_dumb_io/dumb_io.h
+++ b/pw_sys_io/public/pw_sys_io/sys_io.h
@@ -43,30 +43,30 @@
 #include "pw_status/status.h"
 #include "pw_status/status_with_size.h"
 
-namespace pw::dumb_io {
+namespace pw::sys_io {
 
-// Read a single byte from the dumb io backend.
+// Read a single byte from the sys io backend.
 // Implemented by: Backend
 //
 // This function will block until it either succeeds or fails to read a byte
-// from the pw_dumb_io backend.
+// from the pw_sys_io backend.
 //
 // Returns Status::OK if a byte was successfully read.
 Status ReadByte(std::byte* dest);
 
-// Write a single byte out the dumb io backend.
+// Write a single byte out the sys io backend.
 // Implemented by: Backend
 //
 // This function will block until it either succeeds or fails to write a byte
-// out the pw_dumb_io backend.
+// out the pw_sys_io backend.
 //
 // Returns Status::OK if a byte was successfully read.
 Status WriteByte(std::byte b);
 
-// Write a string out the dumb io backend.
+// Write a string out the sys io backend.
 // Implemented by: Backend
 //
-// This function takes a null-terminated string and writes it out the dumb io
+// This function takes a null-terminated string and writes it out the sys io
 // backend, adding any platform-specific newline character(s) (these are
 // accounted for in the returned StatusWithSize).
 //
@@ -75,7 +75,7 @@ Status WriteByte(std::byte b);
 // are returned as part of the StatusWithSize.
 StatusWithSize WriteLine(const std::string_view& s);
 
-// Fill a byte span from the dumb io backend using ReadByte().
+// Fill a byte span from the sys io backend using ReadByte().
 // Implemented by: Facade
 //
 // This function is implemented by this facade and simply uses ReadByte() to
@@ -89,7 +89,7 @@ StatusWithSize WriteLine(const std::string_view& s);
 // are returned as part of the StatusWithSize.
 StatusWithSize ReadBytes(span<std::byte> dest);
 
-// Write span of bytes out the dumb io backend using WriteByte().
+// Write span of bytes out the sys io backend using WriteByte().
 // Implemented by: Facade
 //
 // This function is implemented by this facade and simply writes the source
@@ -103,4 +103,4 @@ StatusWithSize ReadBytes(span<std::byte> dest);
 // are returned as part of the StatusWithSize.
 StatusWithSize WriteBytes(span<const std::byte> src);
 
-}  // namespace pw::dumb_io
+}  // namespace pw::sys_io
diff --git a/pw_dumb_io/dumb_io.cc b/pw_sys_io/sys_io.cc
index 26b9f620e..ed0ab5c5a 100644
--- a/pw_dumb_io/dumb_io.cc
+++ b/pw_sys_io/sys_io.cc
@@ -12,9 +12,9 @@
 // License for the specific language governing permissions and limitations under
 // the License.
 
-#include "pw_dumb_io/dumb_io.h"
+#include "pw_sys_io/sys_io.h"
 
-namespace pw::dumb_io {
+namespace pw::sys_io {
 
 StatusWithSize ReadBytes(span<std::byte> dest) {
   for (size_t i = 0; i < dest.size_bytes(); ++i) {
@@ -36,4 +36,4 @@ StatusWithSize WriteBytes(span<const std::byte> src) {
   return StatusWithSize(src.size_bytes());
 }
 
-}  // namespace pw::dumb_io
+}  // namespace pw::sys_io
diff --git a/pw_dumb_io_baremetal_stm32f429/BUILD b/pw_sys_io_baremetal_stm32f429/BUILD
index 595b3c44a..42f5c32b5 100644
--- a/pw_dumb_io_baremetal_stm32f429/BUILD
+++ b/pw_sys_io_baremetal_stm32f429/BUILD
@@ -17,8 +17,8 @@ package(default_visibility = ["//visibility:public"])
 licenses(["notice"])  # Apache License 2.0
 
 filegroup(
-    name = "pw_dumb_io_baremetal_stm32f429",
+    name = "pw_sys_io_baremetal_stm32f429",
     srcs = [
-        "dumb_io_baremetal.cc",
+        "sys_io_baremetal.cc",
     ],
 )
diff --git a/pw_dumb_io_baremetal_stm32f429/BUILD.gn b/pw_sys_io_baremetal_stm32f429/BUILD.gn
index bdd2aedec..5bff1c206 100644
--- a/pw_dumb_io_baremetal_stm32f429/BUILD.gn
+++ b/pw_sys_io_baremetal_stm32f429/BUILD.gn
@@ -16,15 +16,15 @@ import("$dir_pw_docgen/docs.gni")
 
 # This if statement allows docs to always build even if the target isn't
 # compatible with this backend.
-if (dir_pw_dumb_io_backend == dir_pw_dumb_io_baremetal_stm32f429) {
-  source_set("pw_dumb_io_baremetal_stm32f429") {
+if (dir_pw_sys_io_backend == dir_pw_sys_io_baremetal_stm32f429) {
+  source_set("pw_sys_io_baremetal_stm32f429") {
     public_deps = [ "$dir_pw_boot_armv7m" ]
     deps = [
-      "$dir_pw_dumb_io:default_putget_bytes",
-      "$dir_pw_dumb_io:facade",
       "$dir_pw_preprocessor",
+      "$dir_pw_sys_io:default_putget_bytes",
+      "$dir_pw_sys_io:facade",
     ]
-    sources = [ "dumb_io_baremetal.cc" ]
+    sources = [ "sys_io_baremetal.cc" ]
   }
 }
 
diff --git a/pw_dumb_io_baremetal_stm32f429/docs.rst b/pw_sys_io_baremetal_stm32f429/docs.rst
index b47b88ced..934deca7f 100644
--- a/pw_dumb_io_baremetal_stm32f429/docs.rst
+++ b/pw_sys_io_baremetal_stm32f429/docs.rst
@@ -1,18 +1,18 @@
-.. _chapter-pw-dumb-io-baremetal-stm32f429:
+.. _chapter-pw-sys-io-baremetal-stm32f429:
 
 .. default-domain:: cpp
 
 .. highlight:: sh
 
-------------------------------
-pw_dumb_io_baremetal_stm32f429
-------------------------------
+-----------------------------
+pw_sys_io_baremetal_stm32f429
+-----------------------------
 
-``pw_dumb_io_baremetal_stm32f429`` implements the ``pw_dumb_io`` facade over
+``pw_sys_io_baremetal_stm32f429`` implements the ``pw_sys_io`` facade over
 UART.
 
-The STM32F429 baremetal dumb IO backend provides device startup code and a UART
-driver layer that allows applications built against the ``pw_dumb_io`` interface
+The STM32F429 baremetal sys IO backend provides device startup code and a UART
+driver layer that allows applications built against the ``pw_sys_io`` interface
 to run on a STM32F429 chip and do simple input/output via UART. The code is
 optimized for the STM32F429I-DISC1, using USART1 (which is connected to the
 virtual COM port on the embedded ST-LINKv2 chip). However, this should work with
@@ -25,8 +25,8 @@ Setup
 =====
 This module requires relatively minimal setup:
 
-  1. Write code against the ``pw_dumb_io`` facade.
-  2. Specify the ``dir_pw_dumb_io_backend`` GN global variable to point to this
+  1. Write code against the ``pw_sys_io`` facade.
+  2. Specify the ``dir_pw_sys_io_backend`` GN global variable to point to this
      backend.
   3. Build an executable with a main() function using a toolchain that
      supports Cortex-M4.
@@ -61,5 +61,5 @@ Sample connection diagram
 
 Dependencies
 ============
-  * pw_dumb_io facade
+  * pw_sys_io facade
   * pw_preprocessor module
diff --git a/pw_dumb_io_baremetal_stm32f429/dumb_io_baremetal.cc b/pw_sys_io_baremetal_stm32f429/sys_io_baremetal.cc
index 1810d28bc..3b7415ac3 100644
--- a/pw_dumb_io_baremetal_stm32f429/dumb_io_baremetal.cc
+++ b/pw_sys_io_baremetal_stm32f429/sys_io_baremetal.cc
@@ -15,8 +15,8 @@
 #include <cinttypes>
 
 #include "pw_boot_armv7m/boot.h"
-#include "pw_dumb_io/dumb_io.h"
 #include "pw_preprocessor/compiler.h"
+#include "pw_sys_io/sys_io.h"
 
 namespace {
 
@@ -217,7 +217,7 @@ extern "C" void pw_PreMainInit() {
 #endif  // defined(PW_ARMV7M_ENABLE_FPU) && PW_ARMV7M_ENABLE_FPU == 1
 }
 
-namespace pw::dumb_io {
+namespace pw::sys_io {
 
 // Wait for a byte to read on USART1. This blocks until a byte is read. This is
 // extremely inefficient as it requires the target to burn CPU cycles polling to
@@ -244,7 +244,7 @@ Status WriteByte(std::byte b) {
   return Status::OK;
 }
 
-// Writes a string using pw::dumb_io, and add newline characters at the end.
+// Writes a string using pw::sys_io, and add newline characters at the end.
 StatusWithSize WriteLine(const std::string_view& s) {
   size_t chars_written = 0;
   StatusWithSize result = WriteBytes(as_bytes(span(s)));
@@ -260,4 +260,4 @@ StatusWithSize WriteLine(const std::string_view& s) {
   return StatusWithSize(result.status(), chars_written);
 }
 
-}  // namespace pw::dumb_io
+}  // namespace pw::sys_io
diff --git a/pw_dumb_io_stdio/BUILD b/pw_sys_io_stdio/BUILD
index 0f8da676f..333bd540e 100644
--- a/pw_dumb_io_stdio/BUILD
+++ b/pw_sys_io_stdio/BUILD
@@ -22,10 +22,10 @@ package(default_visibility = ["//visibility:public"])
 licenses(["notice"])  # Apache License 2.0
 
 pw_cc_library(
-    name = "pw_dumb_io_stdio",
-    srcs = ["dumb_io.cc"],
+    name = "pw_sys_io_stdio",
+    srcs = ["sys_io.cc"],
     deps = [
-        "//pw_dumb_io:default_putget_bytes",
-        "//pw_dumb_io:facade",
+        "//pw_sys_io:default_putget_bytes",
+        "//pw_sys_io:facade",
     ],
 )
diff --git a/pw_dumb_io_stdio/BUILD.gn b/pw_sys_io_stdio/BUILD.gn
index 82e4c78c3..a683ab90d 100644
--- a/pw_dumb_io_stdio/BUILD.gn
+++ b/pw_sys_io_stdio/BUILD.gn
@@ -16,13 +16,13 @@ import("$dir_pw_docgen/docs.gni")
 
 # This if statement allows docs to always build even if the target isn't
 # compatible with this backend.
-if (dir_pw_dumb_io_backend == dir_pw_dumb_io_stdio) {
-  source_set("pw_dumb_io_stdio") {
+if (dir_pw_sys_io_backend == dir_pw_sys_io_stdio) {
+  source_set("pw_sys_io_stdio") {
     deps = [
-      "$dir_pw_dumb_io:default_putget_bytes",
-      "$dir_pw_dumb_io:facade",
+      "$dir_pw_sys_io:default_putget_bytes",
+      "$dir_pw_sys_io:facade",
     ]
-    sources = [ "dumb_io.cc" ]
+    sources = [ "sys_io.cc" ]
   }
 }
 
diff --git a/pw_dumb_io_stdio/CMakeLists.txt b/pw_sys_io_stdio/CMakeLists.txt
index 696b0a7fb..5b76f6447 100644
--- a/pw_dumb_io_stdio/CMakeLists.txt
+++ b/pw_sys_io_stdio/CMakeLists.txt
@@ -12,11 +12,11 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
-pw_auto_add_simple_module(pw_dumb_io_stdio
+pw_auto_add_simple_module(pw_sys_io_stdio
   IMPLEMENTS_FACADE
-    pw_dumb_io
+    pw_sys_io
 )
 
-# TODO(hepler): Declare pw_dumb_io_stdio as the pw_dumb_io backend for now.
-add_library(pw_dumb_io.backend INTERFACE)
-target_link_libraries(pw_dumb_io.backend INTERFACE pw_dumb_io_stdio)
+# TODO(hepler): Declare pw_sys_io_stdio as the pw_sys_io backend for now.
+add_library(pw_sys_io.backend INTERFACE)
+target_link_libraries(pw_sys_io.backend INTERFACE pw_sys_io_stdio)
diff --git a/pw_dumb_io_stdio/docs.rst b/pw_sys_io_stdio/docs.rst
index c97a16b57..553efbfa3 100644
--- a/pw_dumb_io_stdio/docs.rst
+++ b/pw_sys_io_stdio/docs.rst
@@ -1,32 +1,32 @@
-.. _chapter-pw-dumb-io-stdio:
+.. _chapter-pw-sys-io-stdio:
 
 .. default-domain:: cpp
 
 .. highlight:: sh
 
-----------------
-pw_dumb_io_stdio
-----------------
-The ``pw_dumb_io_stdio`` backend implements the ``pw_dumb_io`` facade using
+---------------
+pw_sys_io_stdio
+---------------
+The ``pw_sys_io_stdio`` backend implements the ``pw_sys_io`` facade using
 stdio.
 
 Why not just use stdio directly?
 --------------------------------
 
-The nice thing about using ``pw_dumb_io`` is that it's rather easy to get a
+The nice thing about using ``pw_sys_io`` is that it's rather easy to get a
 board up and running with a target-specific backend. This means when drafting
-out a quick application you can write it against ``pw_dumb_io`` and, with some
+out a quick application you can write it against ``pw_sys_io`` and, with some
 care, the application will be able to run on both host and target devices.
 
-While it's not recommended to use ``pw_dumb_io`` for any production
+While it's not recommended to use ``pw_sys_io`` for any production
 applications, it can be rather helpful for early prototyping.
 
 Setup
 =====
 This module requires relatively minimal setup:
 
-  1. Write code against the ``pw_dumb_io`` facade.
-  2. Specify the ``dir_pw_dumb_io_backend`` GN global variable to point to this
+  1. Write code against the ``pw_sys_io`` facade.
+  2. Specify the ``dir_pw_sys_io_backend`` GN global variable to point to this
      backend.
 
 Module usage
@@ -36,4 +36,4 @@ to an application built directly against stdio.
 
 Dependencies
 ============
-  * pw_dumb_io facade
+  * pw_sys_io facade
diff --git a/pw_dumb_io_stdio/dumb_io.cc b/pw_sys_io_stdio/sys_io.cc
index 66a1f45f8..72e4df624 100644
--- a/pw_dumb_io_stdio/dumb_io.cc
+++ b/pw_sys_io_stdio/sys_io.cc
@@ -12,11 +12,11 @@
 // License for the specific language governing permissions and limitations under
 // the License.
 
-#include "pw_dumb_io/dumb_io.h"
+#include "pw_sys_io/sys_io.h"
 
 #include <cstdio>
 
-namespace pw::dumb_io {
+namespace pw::sys_io {
 
 Status ReadByte(std::byte* dest) {
   if (dest == nullptr) {
@@ -55,4 +55,4 @@ StatusWithSize WriteLine(const std::string_view& s) {
   return StatusWithSize(result, chars_written);
 }
 
-}  // namespace pw::dumb_io
+}  // namespace pw::sys_io
diff --git a/pw_unit_test/BUILD b/pw_unit_test/BUILD
index c4d51f49f..053653c65 100644
--- a/pw_unit_test/BUILD
+++ b/pw_unit_test/BUILD
@@ -81,7 +81,7 @@ pw_cc_library(
     deps = [
         ":pw_unit_test",
         ":simple_printing_event_handler",
-        "//pw_dumb_io",
+        "//pw_sys_io",
     ],
 )
 
diff --git a/pw_unit_test/BUILD.gn b/pw_unit_test/BUILD.gn
index 0906df2f2..4283c1438 100644
--- a/pw_unit_test/BUILD.gn
+++ b/pw_unit_test/BUILD.gn
@@ -55,7 +55,7 @@ source_set("simple_printing_main") {
   public_deps = [ ":pw_unit_test" ]
   deps = [
     ":simple_printing_event_handler",
-    "$dir_pw_dumb_io",
+    "$dir_pw_sys_io",
   ]
   sources = [ "simple_printing_main.cc" ]
 }
@@ -76,7 +76,7 @@ if (dir_pw_log_backend != "") {
     public_deps = [ ":pw_unit_test" ]
     deps = [
       ":logging_event_handler",
-      "$dir_pw_dumb_io",
+      "$dir_pw_sys_io",
     ]
     sources = [ "logging_main.cc" ]
   }
diff --git a/pw_unit_test/CMakeLists.txt b/pw_unit_test/CMakeLists.txt
index 7a7e26270..3767b4eff 100644
--- a/pw_unit_test/CMakeLists.txt
+++ b/pw_unit_test/CMakeLists.txt
@@ -32,6 +32,6 @@ pw_add_module_library(pw_unit_test.main
     pw_unit_test
   PRIVATE_DEPS
     pw_preprocessor
-    pw_dumb_io
     pw_string
+    pw_sys_io
 )
diff --git a/pw_unit_test/simple_printing_main.cc b/pw_unit_test/simple_printing_main.cc
index 96fb4dbd7..859f5f878 100644
--- a/pw_unit_test/simple_printing_main.cc
+++ b/pw_unit_test/simple_printing_main.cc
@@ -14,8 +14,8 @@
 
 #include <string_view>
 
-#include "pw_dumb_io/dumb_io.h"
 #include "pw_span/span.h"
+#include "pw_sys_io/sys_io.h"
 #include "pw_unit_test/framework.h"
 #include "pw_unit_test/simple_printing_event_handler.h"
 
@@ -23,9 +23,9 @@ int main() {
   pw::unit_test::SimplePrintingEventHandler handler(
       [](const std::string_view& s, bool append_newline) {
         if (append_newline) {
-          pw::dumb_io::WriteLine(s);
+          pw::sys_io::WriteLine(s);
         } else {
-          pw::dumb_io::WriteBytes(pw::as_bytes(pw::span(s)));
+          pw::sys_io::WriteBytes(pw::as_bytes(pw::span(s)));
         }
       });
 
diff --git a/pw_vars_default.gni b/pw_vars_default.gni
index b7c9ae48e..6de484f35 100644
--- a/pw_vars_default.gni
+++ b/pw_vars_default.gni
@@ -103,12 +103,12 @@ dir_pw_boot_backend = ""
 # Backend for the pw_cpu_exception module.
 dir_pw_cpu_exception_backend = ""
 
-# Backend for the pw_dumb_io module.
-dir_pw_dumb_io_backend = ""
-
 # Backend for the pw_log module.
 dir_pw_log_backend = ""
 
+# Backend for the pw_sys_io module.
+dir_pw_sys_io_backend = ""
+
 ############################## MODULE CONFIGS ##################################
 
 # Module configuration options for pw_boot_armv7m.
diff --git a/targets/host/host_common.gni b/targets/host/host_common.gni
index 4a890c369..bfe5db294 100644
--- a/targets/host/host_common.gni
+++ b/targets/host/host_common.gni
@@ -24,8 +24,8 @@ pw_unit_test_main = "$dir_pw_unit_test:logging_main"
 # Configure backend for assert facade.
 dir_pw_assert_backend = "$dir_pw_assert_basic"
 
-# Configure backend for pw_dumb_io facade.
-dir_pw_dumb_io_backend = "$dir_pw_dumb_io_stdio"
-
 # Configure backend for logging facade.
 dir_pw_log_backend = "$dir_pw_log_basic"
+
+# Configure backend for pw_sys_io facade.
+dir_pw_sys_io_backend = "$dir_pw_sys_io_stdio"
diff --git a/targets/stm32f429i-disc1/target_config.gni b/targets/stm32f429i-disc1/target_config.gni
index 0e589b159..582f18d39 100644
--- a/targets/stm32f429i-disc1/target_config.gni
+++ b/targets/stm32f429i-disc1/target_config.gni
@@ -15,7 +15,7 @@
 # Target configuration for the STM32f429I-DISC1 development board.
 #
 # TODO(amontanez): This target configuration treats
-# pw_dumb_io_baremetal_stm32f429 as if it were a platform. This is for
+# pw_sys_io_baremetal_stm32f429 as if it were a platform. This is for
 # testing/development and should eventually point to something more
 # sophisticated.
 
@@ -44,7 +44,7 @@ template("stm32f429i_executable") {
     if (!defined(deps)) {
       deps = []
     }
-    deps += [ dir_pw_dumb_io_baremetal_stm32f429 ]
+    deps += [ dir_pw_sys_io_baremetal_stm32f429 ]
   }
 }
 
@@ -64,8 +64,8 @@ if (pw_use_test_server) {
 dir_pw_assert_backend = dir_pw_assert_basic
 dir_pw_boot_backend = dir_pw_boot_armv7m
 dir_pw_cpu_exception_backend = dir_pw_cpu_exception_armv7m
-dir_pw_dumb_io_backend = dir_pw_dumb_io_baremetal_stm32f429
 dir_pw_log_backend = dir_pw_log_basic
+dir_pw_sys_io_backend = dir_pw_sys_io_baremetal_stm32f429
 
 pw_boot_armv7m_config.defines += [
   "PW_BOOT_FLASH_BEGIN=0x08000200",