diff --git a/README.md b/README.md
index 543c1ac..9314b73 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,32 @@ cmake --build build
 
 Board configuration files are located in `configs/board/<BOARD>/board.cmake`. When `BOARD` is set, the `TARGET` parameter is ignored.
 
+### STM32F746G-DISCO: the Car HMI Demo
+
+The `stm32f746g-disco` board runs the [car HMI demo](https://github.com/choco-technologies/carhmi-demo)
+out of the box: its `flash.dmd` starts the display (`dmview`), audio
+(`dmaudio`, on the WM8994 codec) and the `carhmi` service, and its
+`sdcard.dmd` downloads the view, which is too big for the flash, to
+`build/sdcard`. Flash the firmware, then send the view to the card in the slot
+(FAT, first partition):
+
+```bash
+cmake -DBOARD=stm32f746g-disco -S . -B build
+cmake --build build
+cmake --build build --target install-all     # the firmware, then build/sdcard over the console
+```
+
+The player plays the MP3 files of `music/` on the card. Copy them there on a
+PC, or send them over the console:
+
+```bash
+scripts/ymodem_send.py --dest /mnt/dmsdio0_0p1/music *.mp3
+```
+
+carhmi reads the directory when it starts: restart it (`service restart carhmi`)
+or the board after adding files - a few seconds after the transfer, so FAT has
+written them to the card.
+
 ### Building for LILYGO T-Deck Pro
 
 The T-Deck Pro is based on the **ESP32-S3FN16R8** (Xtensa LX7 dual-core, 240 MHz, 16 MB flash, 8 MB PSRAM).
diff --git a/configs/board/stm32f746g-disco/flash.dmd b/configs/board/stm32f746g-disco/flash.dmd
index 7e336ad..f4c2f14 100644
--- a/configs/board/stm32f746g-disco/flash.dmd
+++ b/configs/board/stm32f746g-disco/flash.dmd
@@ -74,3 +74,24 @@ dmft5336 driver=board/stm32f746g-disco/touch.ini
 #
 dmsai
 dmwm8994 driver=board/stm32f746g-disco/codec-with-touch.ini
+#
+# The audio service: dmaudio.rules starts a dmaudio@<name> for every audio
+# device dmdevfs reports - here /dev/wm8994 -, mixing what the applications
+# play (libdmaudio) into it.
+#
+dmaudio service=dmaudio@.ini
+dmaudio rules=dmaudio.rules
+#
+# The display service: dmview.rules starts a dmview@<name> for the LCD
+# (/dev/dmlcdtft0), which shows what the applications claim for it - with
+# the channel between an application and its view (0.10), which carhmi needs.
+#
+dmview@>=0.10
+dmview@>=0.10 service=dmview@.ini
+dmview@>=0.10 rules=dmview.rules
+#
+# The car HMI demo (choco-technologies/carhmi-demo): a service that claims the
+# display for its view - on the SD card, see sdcard.dmd - and plays the MP3
+# files of the card's music/ directory through dmaudio.
+#
+carhmi service=carhmi.ini
diff --git a/configs/board/stm32f746g-disco/sdcard.dmd b/configs/board/stm32f746g-disco/sdcard.dmd
index d751c90..b2c5569 100644
--- a/configs/board/stm32f746g-disco/sdcard.dmd
+++ b/configs/board/stm32f746g-disco/sdcard.dmd
@@ -1,3 +1,9 @@
 #
 # STM32F746G Discovery board sdcard modules - board-specific modules for sdcard
 #
+#
+# The car HMI's view (carhmi.dmv with its fonts and images, ~320 kB - too big
+# for the flash): installed to build/sdcard/views/carhmi_view/, it goes to
+# <card>/views/carhmi_view/ (upload-files), where carhmi.ini looks for it.
+#
+carhmi_view
diff --git a/configs/common/flash.dmd b/configs/common/flash.dmd
index 7bca59c..08b3c3c 100644
--- a/configs/common/flash.dmd
+++ b/configs/common/flash.dmd
@@ -12,6 +12,7 @@ mount
 umount
 cat
 catini
+ymodem
 tty
 memory
 systemd
diff --git a/lib/dmod b/lib/dmod
index 336a628..cefe9a3 160000
--- a/lib/dmod
+++ b/lib/dmod
@@ -1 +1 @@
-Subproject commit 336a6281325b513c5b91d6ba3a37d7a1d696fce4
+Subproject commit cefe9a33874e2049d1cf1cb0be2074ed8840e583