diff --git a/src/platform/portduino/PortduinoGlue.cpp b/src/platform/portduino/PortduinoGlue.cpp
index 6f8077720..fbaa3c98c 100644
--- a/src/platform/portduino/PortduinoGlue.cpp
+++ b/src/platform/portduino/PortduinoGlue.cpp
@@ -490,10 +490,17 @@ void portduinoSetup()
             exit(EXIT_FAILURE);
         }
         char serial[9] = {0};
-        ch341Hal->getSerialString(serial, 8);
+        // Pass the full buffer size (9 = 8 chars + null) to getSerialString,
+        // not 8. The function treats `len` as buffer size and reserves one
+        // slot for the null terminator, so passing 8 produced a 7-char serial
+        // and broke the `strlen(serial) == 8` check below — masked on Linux
+        // by the BlueZ HCI MAC fallback in getMacAddr(), but on macOS (where
+        // the BlueZ path is __linux__-guarded) it left mac_address empty and
+        // meshtasticd refused to start.
+        ch341Hal->getSerialString(serial, sizeof(serial));
         std::cout << "CH341 Serial " << serial << std::endl;
         char product_string[96] = {0};
-        ch341Hal->getProductString(product_string, 95);
+        ch341Hal->getProductString(product_string, sizeof(product_string));
         std::cout << "CH341 Product " << product_string << std::endl;
         if (strlen(serial) == 8 && portduino_config.mac_address.length() < 12) {
             std::cout << "Deriving MAC address from Serial and Product String" << std::endl;
diff --git a/variants/native/portduino/platformio.ini b/variants/native/portduino/platformio.ini
index c497d0c17..e493da77b 100644
--- a/variants/native/portduino/platformio.ini
+++ b/variants/native/portduino/platformio.ini
@@ -133,6 +133,39 @@ test_testing_command =
 ;     SOCK_NONBLOCK fallback, Common.h __APPLE__ guard, WiFiServer.cpp extern-C
 ;     fix, package.json URL refresh. Pulled by platform-native at its pinned commit.
 ; This env therefore only carries the firmware-side build flags and src filter.
+;
+; Real LoRa hardware on macOS:
+;   The same lib_dep `pine64/libch341-spi-userspace` used on Linux works on
+;   macOS as-is — its `libusb_detach_kernel_driver()` call is `__linux__`-
+;   guarded, but on macOS the kernel doesn't bind a driver to a CH341A SPI
+;   bridge (PID 0x5512; bDeviceClass=0xff vendor-specific) by default, so
+;   no detach is needed. Apple's bundled CH34x driver targets the CH340
+;   *UART* variant (PID 0x7523) — different product. libusb opens the device
+;   and claims interface 0 directly via IOUSBHostInterface.
+;
+;   To use, point `meshtasticd` at any of the existing `bin/config.d/lora-*.yaml`
+;   files that specify `spidev: ch341` — they're platform-agnostic. Example:
+;     pio run -e native-macos
+;     mkdir -p ~/.meshtasticd && cp bin/config-dist.yaml ~/.meshtasticd/config.yaml
+;     # Edit ~/.meshtasticd/config.yaml: ConfigDirectory: ./config.d/
+;     mkdir ~/.meshtasticd/config.d && cp bin/config.d/lora-meshstick-1262.yaml ~/.meshtasticd/config.d/
+;     cd ~/.meshtasticd && /path/to/firmware/.pio/build/native-macos/meshtasticd
+;
+;   The MAC address auto-derives from the CH341's USB serial + product string
+;   (PortduinoGlue.cpp ~497-518); on Linux a BlueZ HCI socket is the fallback
+;   when that path isn't taken, but BlueZ is `__linux__`-guarded so the
+;   serial-derivation path is mandatory on macOS. Override with
+;   `MACAddress: AA:BB:CC:DD:EE:FF` in config.yaml's `General:` section if
+;   the device's serial isn't 8 hex chars.
+;
+;   Diagnosing CH341 issues on macOS:
+;     ioreg -p IOUSB -l -w 0 | grep -B2 -A30 0x5512
+;       Children should be `IOUSBHostInterface`. If a vendor driver class
+;       (e.g. `com.wch.CH34xVCPDriver` from a third-party WCH installer)
+;       claims interface 0, libusb will fail with LIBUSB_ERROR_BUSY.
+;       Workaround: `sudo kmutil unload -b <bundleID>`.
+;     LIBUSB_DEBUG=4 .pio/build/native-macos/meshtasticd
+;       Verbose libusb trace — useful when claim_interface fails.
 ; ---------------------------------------------------------------------------
 [env:native-macos]
 extends = native_base