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Configure audio on STM32F746G-DISCO: dmsai and dmwm8994 #124

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Merged
JohnAmadis merged 1 commit into from
Oct 11, 2026
Merged

Configure audio on STM32F746G-DISCO: dmsai and dmwm8994 #124

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13 changes: 13 additions & 0 deletions configs/board/stm32f746g-disco/board.cmake
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Expand Up @@ -30,3 +30,16 @@ set(DMBOOT_RENODE_SDCARD_DETECT_PIN 13)
# emulation mode can write the frames it renders to a file (see
# DMBOOT_RENODE_LCD_CAPTURE)
set(DMBOOT_RENODE_LCD "sysbus.ltdc" CACHE STRING "Renode peripheral of the LCD controller")

# Audio (WM8994 codec on I2C3 address 0x1A, fed by SAI2): Renode has neither
# peripheral, and its DMA2 has no circular mode or half-transfer interrupt,
# which the SAI stream needs - configs/renode/STM32F7_Audio.cs supplies all
# three. Emulation mode loads them when DMBOOT_RENODE_AUDIO_CAPTURE is set
# (see there); DMA2 is replaced by a model that moves peripheral-to-memory
# data like Renode's own, so the SD host still works. <capture> stands for the
# file the codec writes what it plays to.
set(DMBOOT_RENODE_AUDIO_MODEL "${CMAKE_SOURCE_DIR}/configs/renode/STM32F7_Audio.cs")
set(DMBOOT_RENODE_AUDIO_DMA "sysbus.dma2")
set(DMBOOT_RENODE_AUDIO_DMA_DESCRIPTION "dma2: DMA.STM32F7_AudioDMA @ sysbus 0x40026400 { [0-7] -> nvic@[56-60,68-70] }")
set(DMBOOT_RENODE_AUDIO_CODEC_DESCRIPTION "wm8994: Sound.WM8994 @ i2c3 0x1A { outputFile: \\\"<capture>\\\" }")
set(DMBOOT_RENODE_AUDIO_SAI_DESCRIPTION "sai2: Sound.STM32F7_SAI @ sysbus 0x40015C00 { codec: wm8994; DmaRequestA -> dma2@4; DmaRequestB -> dma2@6 }")
11 changes: 11 additions & 0 deletions configs/board/stm32f746g-disco/flash.dmd
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Expand Up @@ -63,3 +63,14 @@ dmlcdtft driver=board/stm32f746g-disco/lcd.ini
#
dmi2c
dmft5336 driver=board/stm32f746g-disco/touch.ini
#
# Audio: the WM8994 codec - stereo headphone output and the board's digital
# microphone - on SAI2 (PCM, dmsai) with I2C3 for its registers. The config
# joins the touch panel's I2C3 bus node (touch.ini above) instead of
# configuring I2C3 again, so both work at once. The nodes are /dev/wm8994
# (codec controls and stereo PCM) and /dev/dmsai1 (the raw SAI stream the codec
# drives); an application plays through /dev/wm8994 with the DMDRVI_IOCTL_AUDIO_*
# commands (dmdrvi 2.7). dmsai needs dmclk (SAI clock), dmdma (DMA2) and dmheap.
#
dmsai
dmwm8994 driver=board/stm32f746g-disco/codec-with-touch.ini
11 changes: 7 additions & 4 deletions configs/renode/STM32F7_Audio.cs
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Expand Up @@ -21,17 +21,20 @@
// LRCLK/BCLK inversion) and writes the DAC1 samples it receives to OutputFile
// as raw stereo s16le (silence while DAC1 is muted).
//
// Not wired into renode.resc yet. To use it, add to the script before
// LoadELF (the codec node also needs dmsai/dmwm8994 in the firmware and the
// FT5336 touch config left out, since both own I2C3):
// Loaded by renode.resc when DMBOOT_RENODE_AUDIO_CAPTURE names a file (the
// board's board.cmake names the peripherals, scripts/targets.cmake writes the
// script lines):
//
// include @configs/renode/STM32F7_Audio.cs
// sysbus Unregister sysbus.dma2
// machine LoadPlatformDescriptionFromString "dma2: DMA.STM32F7_AudioDMA @ sysbus 0x40026400 { [0-7] -> nvic@[56-60,68-70] }"
// machine LoadPlatformDescriptionFromString "wm8994: Sound.WM8994 @ i2c3 0x1A { outputFile: \"/tmp/codec.pcm\" }"
// machine LoadPlatformDescriptionFromString "sai2: Sound.STM32F7_SAI @ sysbus 0x40015C00 { codec: wm8994; DmaRequestA -> dma2@4; DmaRequestB -> dma2@6 }"
//
// and convert the capture with e.g. "sox -t raw -r 48000 -e signed -b 16 -c 2 /tmp/codec.pcm out.wav".
// DMA2 has to be replaced before anything that connects to it by name (the SD
// host). The codec shares I2C3 with the touch panel, as on the board
// (flash.dmd). Convert the capture with e.g.
// "sox -t raw -r 48000 -e signed -b 16 -c 2 /tmp/codec.pcm out.wav".
//
using System;
using System.Collections.Generic;
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2 changes: 2 additions & 0 deletions configs/renode/renode.resc.in
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Expand Up @@ -6,6 +6,8 @@ sysbus LoadELF @@CMAKE_BINARY_DIR@/renode_firmware.elf

machine StartGdbServer 3333

@DMBOOT_RENODE_AUDIO_SETUP@

@DMBOOT_RENODE_SDCARD_SETUP@

@DMBOOT_RENODE_LCD_SETUP@
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1 change: 1 addition & 0 deletions docs/cmake-options.md
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Expand Up @@ -29,6 +29,7 @@ These options are defined in the top-level `CMakeLists.txt` and control the over
| `DMBOOT_RENODE_TAP` | STRING | *(empty)* | In emulation mode, host TAP interface (e.g. `tap0`) that the board's Ethernet controller (`DMBOOT_RENODE_ETHERNET`, set by the board config, e.g. `sysbus.ethernet` for `stm32f746g-disco`) is connected to through a Renode switch, so the host can reach the board over IP. Needs root and `/dev/net/tun`; empty leaves the Ethernet unconnected. |
| `DMBOOT_RENODE_SDCARD` | FILEPATH | *(empty)* | In emulation mode, SD card image (e.g. one built by `scripts/make_sdcard_image.py`) inserted in the board's card slot (`DMBOOT_RENODE_SDMMC`, set by the board config, e.g. `sysbus.sdmmc` for `stm32f746g-disco`). The board's SD host is replaced with its own model (`configs/renode/STM32F7_SDMMC.cs`, compiled by Renode when it loads the script) and the card detect pin is driven low. Writes to the card are discarded when Renode exits; empty leaves the slot empty. |
| `DMBOOT_RENODE_LCD_CAPTURE` | FILEPATH | *(empty)* | In emulation mode, file every frame the board's LCD controller (`DMBOOT_RENODE_LCD`, set by the board config, e.g. `sysbus.ltdc` for `stm32f746g-disco`) renders is written to whenever it changes: a header line `DMLCD <width> <height> <pixel format> <endianness>` followed by the raw pixels (see `configs/renode/lcd_capture.py.in`). Empty: frames are not captured. |
| `DMBOOT_RENODE_AUDIO_CAPTURE` | FILEPATH | *(empty)* | In emulation mode, file the board's audio codec (`stm32f746g-disco`: WM8994 on I2C3, fed by SAI2) writes what it plays to, as raw stereo 16-bit little-endian samples at the codec's rate (48 kHz). Setting it loads `configs/renode/STM32F7_Audio.cs`, which adds the SAI and the codec and replaces DMA2 with a model that has circular mode and half-transfer interrupts (Renode's has neither; the SD host keeps working). Needs the audio modules from `flash.dmd`. Empty: the audio peripherals are not modelled and the codec does not respond. |

## VFS Options

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15 changes: 15 additions & 0 deletions scripts/targets.cmake
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Expand Up @@ -51,6 +51,21 @@ if(DMBOOT_RENODE_ETHERNET AND DMBOOT_RENODE_TAP)
else()
set(DMBOOT_RENODE_NETWORK "")
endif()
# Play audio through the board's codec (if it names the models): the DMA2
# controller is replaced with one that has circular mode and half-transfer
# interrupts, and the SAI and the WM8994 codec are added (see
# DMBOOT_RENODE_AUDIO_MODEL, a C# model Renode compiles when it loads the
# script). What the codec plays is written to a file as raw stereo 16-bit
# little-endian samples. The SD card setup below connects to DMA2 by name, so
# DMA2 has to be replaced first.
set(DMBOOT_RENODE_AUDIO_CAPTURE "" CACHE FILEPATH "File the board's audio codec writes what it plays to in emulation mode (raw stereo s16le); empty: the audio models are not loaded")
if(DMBOOT_RENODE_AUDIO_MODEL AND DMBOOT_RENODE_AUDIO_CAPTURE)
string(REPLACE "<capture>" "${DMBOOT_RENODE_AUDIO_CAPTURE}" _AUDIO_CODEC "${DMBOOT_RENODE_AUDIO_CODEC_DESCRIPTION}")
set(DMBOOT_RENODE_AUDIO_SETUP
"include @${DMBOOT_RENODE_AUDIO_MODEL}\nsysbus Unregister ${DMBOOT_RENODE_AUDIO_DMA}\nmachine LoadPlatformDescriptionFromString \"${DMBOOT_RENODE_AUDIO_DMA_DESCRIPTION}\"\nmachine LoadPlatformDescriptionFromString \"${_AUDIO_CODEC}\"\nmachine LoadPlatformDescriptionFromString \"${DMBOOT_RENODE_AUDIO_SAI_DESCRIPTION}\"")
else()
set(DMBOOT_RENODE_AUDIO_SETUP "")
endif()
# Insert an SD card image in the board's card slot (if it names one): the
# board's SD host is replaced with its model (DMBOOT_RENODE_SDMMC_MODEL, C#
# Renode compiles when it loads the script), the image attached to it and the
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