In the i.MX 8M Plus LPDDR4 EVK board there are two Type-C port design. For the port0 is used to power supply no usb function, for the port1 used for USB function but without PD function. But in customer’s design, customer only use one USB design on their board, how to make the one USB work with the PD and USB function, we need to make the hardware design and software modify. This article only give method to realized it and have tested and realized the port1 PD function. 1 Introduction of the USB interface on i.MX8MP         There are two USB 3.0 TypeC controllers with integrated PHY interface on the i.MX8MP: Backward compatibility with USB 2.0 Spread spectrum clock support   The USB on the i.MX8MP supports USB3.0 and is compatible with USB2.0 downward. We can see that the upper layer is the universal layer for USB 2.0 and USB 3.0 operations. This is a common interface, buffer management block, list processor, used to schedule and control the status register (CSR) function： USB 2.0 physical layer and MAC layer USB 3.0 physical layer, link layer and MAC layer   Features of USB 3.0: USB compliant version 3.0 (xHCI compatible) Supports operation as a stand-alone USB host controller USB dual role operation, configurable as host or device Ultra high speed (5Gbit/s), high speed (480Mbit/s), full speed (12Mbit/s) and low speed (1.5Mbit/s) operation. Support independent single port USB operation Support for four programmable bidirectional USB endpoints Support system memory interface with 40 bit addressing capability   2 Design of USB on Development Board         The i.MX 8M Plus processor includes two USB 2.0/3.0 controllers and two integrated USB PHYs. USB supports both running as an independent USB host controller and dual role USB operation, and can be configured as a host or device. Therefore, the design of these two functions is implemented on the development board of i.MX8MP.   We can see that on the development board, one USB1 is used for the USB Type-C port and the other USB2 is used for the USB 3.0 host port. USB Type-C port 0 (J5) is only used for power supply. It does not support USB data transfer. It is the only power port, so the system must always be powered.   On the CPU side of the schematic diagram, we can also see that USB1 is the port for USB Type-C, and USB2 is the host for USB3.0.    USB1 is designed as USB Type-C:   USB2 USB3.0 Host design：   Power design of the USB Type-C port：   3 Only one USB interface is used in the design (compatible with both USB PD function and USB dual roles function)         Two USB Type-C ports are used on our development board. One is used to power the board separately, and the other is used as the function of USB Type-C. However, due to the limited design cost and chip layout and space on the board, some customers will use a USB interface to realize the dual role function of power supply and USB. How to achieve this? USB Device(Download mode)：     USB　Host mode（power+device　Need the hub support PD function）:     The specific implementation and design are as follows: 3.1 Hardware realize PTN5110 To realize the USB Type-C support power supply function, PTN5110 (USB PD TCPC PHY IC) chip is required to realize Type-C data logic and power control and management. The selection of PTN5110 is critical and important.   PTN5110 is a single port USB PD (power supply) PHY IC that conforms to TCPC. It integrates Type-C configuration channel (CC) interface and USB PD physical layer functions into Type-C port manager (TCPM) that handles PD policy management. It complies with USB PD, Type-C and TCPC specifications.   The IC is mainly aimed at applications in system platforms (such as laptops, desktops, Chromebooks, tablets, flip notebooks, etc.). Other application cases may be feasible, depending on the application architecture, such as docking stations, displays, accessories, cable adapters, smartphones, etc.   It can support various Type-C applications: Sink, Source, Sink with accessory support or DRP. It executes Type-C CC simulation part (i.e. Rd/Rp/Ra detection, Rd/Rp indication) and PD Tx/Rx PHY and protocol state machine. PTN5110 supports TCPM in the system implementation of the following PD roles.   PTN5110 integrates VCONN load switch, programmable current limit, reverse leakage current blocking and over temperature protection (OTP). It is equipped with two enable control outputs to control the load switch/FET in the VBUS pull and/or sink path. It can also perform VBUS voltage monitoring/measurement, VBUS forced discharge and discharge discharge.   PTN5110 provides the main IO related functions for the main processor/TCPM, so that Type-C/PD interfaces can be easily controlled and managed through the TCPC interface.   PTN5110 supports a wide range of power input voltages, providing platform integrators with great flexibility. PTN5110 can run on VBUS to support specific system use cases that require no power operation.https://www.nxp.com/products/interfaces/usb-interfaces/usb-type-c/usb-pd-phy-and-cc-logic/usb-pd-tcpc-phy-ic:PTN5110   The design only use the USB1：   Here, it is required to weld R53 or R54. You can refer to this design completely. 2 Software modify Modify the BPS of the software: Take the newest released Linux 5.15.32_2.0.0​ as example: In the u-boot /board/freescale/imx8mp_evk/imx8mp_evk.c     It can be seen that the PD function of the port is turned off, so if you want to use USB1 for power supply, remove the following commands and turn on the PD function of USB1. “-   .disable_pd = true,” Use the above action to enable Port1 PD function. Kernel section modify： Kernel section modify towards to PTN5110. Type-C Configure channel (CC) interface： root/drivers/usb/typec/tcpm/tcpci.c @@ -524,6 +524,7 @@ static int tcpci_vbus_force_discharge(struct tcpc_dev *tcpc, bool enable)  static int tcpci_set_vbus(struct tcpc_dev *tcpc, bool source, bool sink)  {        struct tcpci *tcpci = tcpc_to_tcpci(tcpc); +      unsigned int reg;        int ret;          if (tcpci->data->set_vbus) { @@ -533,16 +534,20 @@ static int tcpci_set_vbus(struct tcpc_dev *tcpc, bool source, bool sink)                         return ret < 0 ? ret : 0;        }   +      ret = regmap_read(tcpci->regmap, TCPC_POWER_STATUS, &reg); +      if (ret < 0) +              return ret; +        /* Disable both source and sink first before enabling anything */   -       if (!source) { +      if (!source && (reg & TCPC_POWER_STATUS_SOURCING_VBUS)) {                 ret = regmap_write(tcpci->regmap, TCPC_COMMAND,                                     TCPC_CMD_DISABLE_SRC_VBUS);                 if (ret < 0)                         return ret;        }   -       if (!sink) { +      if (!sink && (reg & TCPC_POWER_STATUS_SINKING_VBUS)) {                 ret = regmap_write(tcpci->regmap, TCPC_COMMAND,                                     TCPC_CMD_DISABLE_SINK_VBUS);                 if (ret < 0)   Type-C port manager managed by PD (TCPM)： root/drivers/usb/typec/tcpm /tcpm.c @@ -340,6 +340,7 @@ struct tcpm_port {         */        bool vbus_vsafe0v;   +      bool vbus_keep;        bool vbus_never_low;        bool vbus_source;        bool vbus_charge; @@ -3662,7 +3663,8 @@ static void tcpm_reset_port(struct tcpm_port *port)        port->rx_msgid = -1;          port->tcpc->set_pd_rx(port->tcpc, false); -       tcpm_init_vbus(port);     /* also disables charging */ +      if (!port->vbus_keep) +              tcpm_init_vbus(port);  /* also disables charging */        tcpm_init_vconn(port);        tcpm_set_current_limit(port, 0, 0);        tcpm_set_polarity(port, TYPEC_POLARITY_CC1); @@ -5834,6 +5836,9 @@ static void tcpm_init(struct tcpm_port *port)          port->tcpc->init(port->tcpc);   +      port->vbus_present = port->tcpc->get_vbus(port->tcpc); +      if (port->vbus_present) +              port->vbus_keep = true;        tcpm_reset_port(port);          /* @@ -5872,7 +5877,10 @@ static void tcpm_init(struct tcpm_port *port)         * Some adapters need a clean slate at startup, and won't recover         * otherwise. So do not try to be fancy and force a clean disconnect.         */ -       tcpm_set_state(port, PORT_RESET, 0); +      if (!port->vbus_keep) +              tcpm_set_state(port, PORT_RESET, 0); + +      port->vbus_keep = false;  }    static int tcpm_port_type_set(struct typec_port *p, enum typec_port_type type) Note: The software just needs to modify these two parts. You also need to mention to the proper the I2C port use, if not proper the driver of the PTN5110 can not driver. 4 Test         In our i. MX8MP EVK development board show that R53 and R54 in the USB1 part of our development board are in DNP status, so VBUS_ IN is disconnected and no power comes in. Here, connect R53 or R54 with solder, so that VBUS_ IN, the power comes in again. After the power is connected. The board can be powered through USB1. 4.1 Download images to the emmc on the Board: Power from the USB1, set the boot mode to serial download mode, then go to download images finished. 4.2 Boot up the board from the EMMC Change the boot mode to boot up from EMMC，the board boot up, the log file is as following show：   It will stop at the TCPC for the section of PTN5110 driver. By default, the PD function of port1 in the u-boot is turned off, so if you want to use USB1 for power supply, remove the following commands and turn on the PD function of USB1. “-   .disable_pd = true,” After the PD function is turned on, the board can be started normally, but the whole part running to the kernel will be powered down, so the kernel part of PTN5110 still needs to be modified. After the patch modification of the above kernel part, the board can run normally.         I also did the same experiment on the i.MX8MM EVK development board. The same phenomenon occurs when the kernel starts. Therefore, similar modifications to the above i. MX8MP can work normally. Summary: In one word i.MX8MP and i.MX8M series can realize the role of using a USB for power supply and USB Dual. The hardware design refers to our development board, and we must use the logic chip PTN5110. For software, refer to the above code modification.  

  Anyone who want to use this solution should get reference design and firmware from Lontium. Hardware Here is the block diagram of LT9611UXC Demo Board. As the MIPI port of our EVK can provide 5V, 3V3 and 1V8.We can remove useless DC-DC chips from reference design. Below is the LT9611UXC Demo Board. Software Download the firmware into LT9611UXC. In Linux side, we need to drive the MIPI to output signals with standard timings of 1080P. Panel type diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts index 1732b5c72380..c6a829be541f 100644 --- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts +++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts @@ -696,13 +716,17 @@ &ldb_phy { &mipi_dsi { status = "okay"; + panel@0{ + compatible = "nxp,lt9611uxc"; + reg = <0>; + status = "okay"; }; }; &snvs_pwrkey { diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 4f78bbf63f33..90d99f12515b 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -4997,6 +4997,34 @@ struct panel_desc_dsi { unsigned int lanes; }; +static const struct drm_display_mode lt9611_panel_mode = { + .clock = 148500, + .hdisplay = 1920, + .hsync_start = 1920 + 88, + .hsync_end = 1920 + 88 + 44, + .htotal = 1920 + 88 + 44 + 148, + .vdisplay = 1080, + .vsync_start = 1080 + 4, + .vsync_end = 1080 + 4 + 5, + .vtotal = 1080 + 4 + 5 + 36, +}; + +static const struct panel_desc_dsi lt9611_panel = { + .desc = { + .modes = &lt9611_panel_mode, + .num_modes = 1, + .bpc = 8, + .size = { + .width = 62, + .height = 110, + }, + .connector_type = DRM_MODE_CONNECTOR_DSI, + }, + .flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_NO_EOT_PACKET | MIPI_DSI_MODE_VIDEO_SYNC_PULSE, + .format = MIPI_DSI_FMT_RGB888, + .lanes = 4, +}; + static const struct drm_display_mode auo_b080uan01_mode = { .clock = 154500, .hdisplay = 1200, @@ -5201,6 +5229,9 @@ static const struct panel_desc_dsi osd101t2045_53ts = { static const struct of_device_id dsi_of_match[] = { { + .compatible = "nxp,lt9611uxc", + .data = &lt9611_panel, + },{ .compatible = "auo,b080uan01", .data = &auo_b080uan01 }, {

Some customer need to test ENET IEEE1588 1pps ouput signal. This article describe all i.MX8 serials test procedure, including normal ENET port and EQOS port(i.MX8MP & i.MX8DXL support EQOS).

 This article instruct customer how to develop on i.MX8MP NPU and how to debug performance. 

Materials: i.MX8M Plus EVK Rev. A USB cable type-C USB cable type-B AC Adapter EA1045CR Micro SD (Optional) 88W8997-based wireless modules Software: Yocto Project Mobaxterm Personal Edition v20.2 Build 4296 This test was done on an i.MX8M Plus EVK with Linux 5.10. Hardknott.   To achieve this, you need to identify your WI-FI module and look for the necessary drivers for that module, in my case I am using the 88W8997 module that comes with the i.MX8M Plus, but you can select any other WI-FI module you want.   In my case I build a basic image on Yocto, following the Yocto users guide, I bitbake just the core boot image that allows me to boot the i.MX8M plus. Deploy your image on an SD or eMMC. These instructions apply to SD and MMC cards although for brevity, and usually, only the SD card is listed. For a Linux image to be able to run, four separate pieces are needed: Linux OS kernel image (zImage/Image) Device tree file (*.dtb) Bootloader image Root file system (i.e., EXT4)   The Yocto Project build creates an SD card image that can be flashed directly. This is the simplest way to load everything needed onto the card with one command. A .wic image contains all four images properly configured for an SD card. The release contains a pre-built .wic image that is built specifically for the one board configuration. It runs the Wayland graphical backend. It does not run on other boards unless U-Boot, the device tree, and rootfs are changed. When more flexibility is desired, the individual components can be loaded separately, and those instructions are included here as well. An SD card can be loaded with the individual components one-by-one or the .wic image can be loaded and the individual parts can be overwritten with specific components. The rootfs on the default .wic image is limited to a bit less than 4 GB, but re-partitioning and re-loading the rootfs can increase that to the size of the card. The rootfs can also be changed to specify the graphical backend that is used. Carry out the following command to copy the SD card image to the SD/MMC card. Change sdx below to match the one used by the SD card. $ sudo dd if=<image name>.wic of=/dev/sdx bs=1M && sync The entire contents of the SD card are replaced. If the SD card is larger than 4 GB, the additional space is not accessible. As this build does not contain the driver integrated we need to add it manually on Linux user space. Follow these instructions to load the driver modules and bring up the 88W8987-based wireless module, more info can be found on the next link: https://www.nxp.com/products/wireless/wi-fi-plus-bluetooth/2-4-5-ghz-dual-band-2x2-wi-fi-5-802-11ac-plus-bluetooth-5-3-solution:88W8997?tab=Documentation_Tab   Use the nano editor included in the pre-built image to edit and verify the module parameters in the wifi_mod_para.conf configuration file.   Add the following lines to the configuration file: PCIE8997 = { cfg80211_wext=0xf wfd_name=p2p max_vir_bss=1 cal_data_cfg=none drv_mode=7 ps_mode=2 auto_ds=2 fw_name=nxp/pcieuart8997_combo_v4.bin } Load the modules in the kernel:   Verify the kernel debug messages in the command output   Verify that the module is now visible to the system:     Now that the module is ready to work, we need to enable it, in my case the Wi-Fi is named mlan0, it could vary on other Linux systems.   In the case you need to see which networks are available you can scan it and select the one you need.   Identify your network and add it to the  WPA supplicant file:     Associate the Wi-Fi with config:   Check if you have right SSID associated:   Use DHPC to get the IP   Ping any public site you know to check the network.   In the case you have a Temporary failure in name resolution you will need to change the default DNS that was assigned by DHCP:     Modify /etc/resolv.conf file and add the DNS of your preference, for my case I add the one that uses Google, as they have access to the most common web pages.   And with that should work.    

  From L5.4 BSP, the iMX8QM HDMI RX feature is removed from BSP, but it is added back in L5.10.52 2.1.0 BSP. The followed is the detail steps to use HDMI RX.   We need enable the followed kernel config to make hdmirx driver work:     CONFIG_IMX8_MEDIA_DEVICE=y     CONFIG_MHDP_HDMIRX=y apply the attached kernel patch. put hdmi firmware “hdmirxfw.bin” and “hdmitxfw.bin” to SD card’s FAT partition test command:     gst-launch-1.0 v4l2src device=/dev/video2 ! autovideosink   Note: To test the hdmi feature, the display should also use the HDMI TX. And in Uboot, to load the hdmirx firmware, we can run the followed commands first, then run the "boot" command:     run loadhdprx     hdprx load 0x9c800000     setenv fdt_file imx8qm-mek-hdmi-rx.dtb  

 

     

1.  Introduction 1.1.        Purpose This application note introduces a procedure of how to port AVB/TSN stack and run referring feature demos on i.MX8DXL board. This can help users who want to run AVB/TSN demos to quickly understand and customized their own codes. Since many of the standards are only for TSN switch/bridges and i.MX8DXL is design to be a TSN/AVB endpoint, the demos did not implement a full stack or full standards. They only demonstrated the basic end-to-end point (talker to listener) A/V streaming without bridge or switch. The software used for example in this documentation are based on the opensource such as gstreamer and alsa utils.   1.2.        Overview 1.2.1.     AVB/TSN AVB (Audio Video Bridging) is a common name for the set of technical standards which provide improved synchronization, low-latency, and reliability for switched ethernet network. AVB was initially developed by the IEEE Audio Video Bridging task group of the IEEE 802.1 standards committee. In November 2012, AVB group was renamed to TSN (Time-Sensitive Networking) task group to reflect the expanded scope of its work, which is to provide the specifications that will allow time-synchronized low latency streaming services through IEEE 802 networks. The referring standards shows as follows:     TSN protocol additions QoS components supported in HW TSN MAC + SW driver Managed Object components expose i/f to allow support of standardized network config protocols (local & remote) Transport API to allow other transport layer to use TSN QoS Stack extensions to map traffic priority to application task scheduling Real Time, gPTP based, Best Effort 1.2.2.     Demo introduction   The two streams are defined as below to grantee time sensitive (sub-microsecond synchronization), low latency and bandwidth on the ethernet: Stream A: SR class A, AVTP Audio Format, PCM 16-bit sample, 48 kHz, stereo, 12 frames per AVTPDU. Stream B: SR class B, AVTP Compressed Video Format, H.264 profile High, 1920x1080, 30 fps. The two TSN streams would be allocated into different TC (traffic control) class for egress. Different TC class would be mapped to different hardware queues with specific DMA channel which supported by ENET_OoS IP. The demos were built by follow blocks:   Linux Traffic Control: streams egress control Linux ptp: clock sync in network Libavtp: Time Sensitive Applications AV Transport protocol Gstreamer: avtp plugin uses the libavtp to transmit and receive AVTP audio/video (audio pcm, video h264).   1.2.3.     Traffic control Multiply queue qdiscs + CBS: The CBS class is actually handled by hardware IP to select which queue for transmitting.   CBS parameters come straight from the IEEE 802.1Q-2018 specification. They are the following: idleSlope: rate credits are accumulated when queue isn’t transmitting; sendSlope: rate credits are spent when queue is transmitting; hiCredit: maximum amount of credits the queue is allowed to have; loCredit: minimum amount of credits the queue is allowed to have;     2.  Build demo 2.1.        Build yocto $ DISTRO=fsl-imx-xwayland MACHINE=imx8dxlevk source imx-setup-release.sh -b ./xwayland $ bitbake imx-image-full Prepare a SD card and burn it with the built out images. 2.2.        Rebuild kernel Rebuild the kernel after applying the 0001-qenet-add-queue-avoid-panic.patch, and overwrite the Image and imx8dxl-evk.dtb on the boot partition of the SD card. 2.3.        Install the toolchain $ bitbake -f fsl-image-validation-imx -c populate_sdk $ sh tmp/deploy/sdk/fsl-imx-xwayland-glibc-x86_64-fsl-image-validation-imx-aarch64-imx8dxlevk-toolchain-5.4-zeus.sh The toolchain would be installed into /opt/fsl-imx-xwayland/5.4-zeus   2.4.        Create a install folder $ mkdir <your install folder> Create a folder to install all of the shared libraries, binaries and configure files which built out manually in this doc. After built done, you should copy all of the contents in this folder to target board root.   2.5.        Build libavtp $ source /opt/fsl-imx-xwayland/5.4-zeus/environment-setup-aarch64-poky-linux $ git clone https://github.com/Avnu/libavtp.git $ cd libavtp $ meson build --prefix=<your install folder>/usr $ ninja -C build Copy the built out .so and .pc into the toolchain rootfs: $ sudo cp build/libavtp.so* /opt/fsl-imx-xwayland/5.4-zeus/sysroots/aarch64-poky-linux/usr/lib $ sudo cp build/meson-private/*.pc /opt/fsl-imx-xwayland/5.4-zeus/sysroots/aarch64-poky-linux/usr/lib/pkgconfig/ Copy the .so into the install folder: $ cp build/libavtp.so* <install folder>/usr/lib/ To make sure you have avtp package installed correctly:     $ pkg-config --list-all | grep avtp   2.6.        Build ALSA aaf plugin $ cd <yocto build>/tmp/work/aarch64-poky-linux/alsa-plugins/1.1.9-r0/alsa-plugins-1.1.9 $ ./configure --build=x86_64-linux --host=aarch64-poky-linux --target=aarch64-poky-linux --prefix=<install folder>/usr --disable-silent-rules --disable-dependency-tracking --with-libtool-sysroot=<yocto build>/xwayland/tmp/work/aarch64-poky-linux/alsa-plugins/1.1.9-r0/recipe-sysroot --disable-static --enable-aaf --disable-jack --disable-libav --disable-maemo-plugin --disable-maemo-resource-manager --enable-pulseaudio --enable-samplerate --with-speex=lib $ make $ make install   2.7.        Build Gstreamer AVTP plugins （1.17.x） 2.7.1.     Build Gstreamer core $ git clone https://gitlab.freedesktop.org/gstreamer/gstreamer.git $ patch -p1 < gstreamer-1.0-pass-build.patch $ meson build --prefix=<install folder>/usr $ ninja -C build $ sudo ninja -C build install After Gstreamer is installed into <your install folder>, please fix the “prefix” path in the .pc files by, and copy to the toolchain folders: $ cd <your install folder> $ grep -lR <your install folder> ./lib/pkgconfig/ | xargs sed -i 's/<your install folder>/\/usr/g' $ cp -rf ./usr/* /opt/fsl-imx-xwayland/5.4-zeus/sysroots/aarch64-poky-linux/usr/ 2.7.2.     Build gst-plugins-base $ git clone https://gitlab.freedesktop.org/gstreamer/gst-plugins-base.git $ cd gst-plugins-base $ patch -p1 < gst-plugins-base-pass-build.patch $ meson build --prefix=<your install folder>/usr $ ninja -C build $ sudo ninja -C build install   2.7.3.     Build gst-plugins-bad $ git clone https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad.git $ cd gst-plugins-bad $ meson build --prefix=<your install folder>/usr $ ninja -C build $ sudo ninja -C build install   After gst-plugins-base and gst-plugins-bad installed into <your install folder>, please fix the “prefix” path in the .pc files and copy them into the toolchain folders: $ cd <your install folder> $ grep -lR <your install folder> ./lib/pkgconfig/ | xargs sed -i 's/<your install folder>/\/usr/g' $ cp -rf ./usr/* /opt/fsl-imx-xwayland/5.4-zeus/sysroots/aarch64-poky-linux/usr/   2.8.        Build H.264 SW plugins 2.8.1.     Build x264 As the yocto actually has the x264 recipes, but not included in our bblayers, we need to copy the x264 source into our bblayers path under <yocto>/source to build: $ cp -rf ./poky/meta/recipes-multimedia/x264 ./meta-openembedded/meta-multimedia/recipes-multimedia/ $ vi ./meta-openembedded/meta-multimedia/recipes-multimedia/x264_git.bb Remove the LICENSE_FLAGS line $ bitbake -f x264 -c do_install $ sudo cp -rf tmp/work/aarch64-poky-linux/x264/r2917+gitAUTOINC+72db437770-r0/image/usr/* /opt/fsl-imx-xwayland/5.4-zeus/sysroots/aarch64-poky-linux/usr/ 2.8.2.     Build gst-plugins-ugly $ git clone https://gitlab.freedesktop.org/gstreamer/gst-plugins-ugly.git $ cd gst-plugins-ugly $ meson build --prefix=<your install folder>/usr $ ninja -C build $ sudo ninja -C build install   2.8.3.     Build libav $ cp -rf poky/meta/recipes-multimedia/gstreamer/gstreamer1.0-libav meta-openembedded/meta-multimedia/recipes-multimedia/gstreamer-1.0/ Remove the LICENSE_FLAGS line $ vim ./poky/meta/recipes-multimedia/gstreamer/gstreamer1.0-libav_1.16.2.bb $ bitbake -f gstreamer1.0-libav -c do_install $ cp /opt/samba/nxf39444/imx-yocto-bsp-i.mx8dxl/xwayland/tmp/work/aarch64-poky-linux/gstreamer1.0-libav/1.16.2-r0/image/usr/lib/gstreamer-1.0/libgstlibav.so <your install folder>/usr/lib/gstreamer-1.0   2.8.4.     Install binaries Final step is to copy all of your built out files from <your install folder> into your board / root, and boot up the board. $ export GST_PLUGIN_PATH=/usr/lib/gstreamer-1.0/ $ gst-inspect-1.0 To check if the above Gstreamer plugins we built out can be found by gst-instpect.   3.  System Setup 3.1.        VLAN The ENTE_QoS is assigned to eth0 instance. So create eth0.5 for vlan id 5: $ ip link add link eth0 name eth0.5 type vlan id 5 egress-qos-map 2:2 3:3 $ ip link set eth0.5 up   3.2.        Qdiscs The TSN control plane is implemented through the TC (Traffic Control) system. The transmission algorithms specified in the FQTSS (Forwarding and Queuing for Time-Sensitive Streams) chapter of IEEE 802.1Q-2018 are supported via TC Qdiscs (Queuing Discipline). 3.2.1.     MQPRIO qdisc $ tc qdisc add dev eth0 parent root handle 100 mqprio num_tc 3 map 0 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0 queues 1@0 1@1 1@2 hw 1 3.2.2.     CBS qdisc Q1 CBS for audio, Q2 CBS for video: $ tc qdisc replace dev eth0 parent 100:3 handle 888 cbs idleslope 3648 sendslope -996352 hicredit 12 locredit -113 offload 1 $ tc qdisc replace dev eth0 parent 100:2 handle 777 cbs idleslope 98688 sendslope -901312 hicredit 153 locredit -1389 offload 1 3.2.3.     TimeSync Run the ptp4l and phc2sys in background, and use check_clocks to check the ptp sync works. $ ptp4l -i eth0 -f ./gPTP.cfg --step_threshold=1 & $ pmc -u -b 0 -t 1 "SET GRANDMASTER_SETTINGS_NP clockClass 248 clockAccuracy 0xfe offsetScaledLogVariance 0xffff currentUtcOffset 37 leap61 0 leap59 0 currentUtcOffsetValid 1 ptpTimescale 1 timeTraceable 1 frequencyTraceable 0 timeSource 0xa0" $ ./check_clocks -d eth0 4.  Run demo 4.1.        ALSA AAF audio To run the alsa AAF demo, please add aaf0 and converter0 plugin device into /etc/asound.conf: pcm.aaf0 {    type aaf    ifname eth0.5    addr 01:AA:AA:AA:AA:AA    prio 2    streamid AA:BB:CC:DD:EE:FF:000B    mtt 50000    time_uncertainty 1000    frames_per_pdu 12    ptime_tolerance 100 } pcm.converter0 {    type linear    slave {                  pcm "hw:0,0"                  format S16_LE    } } The “aaf0” plugin device defines the ethernet interface which AAF runs on, the socket priority which mapping to Traffic Class in kernel TC, the stream-id for the aaf streaming. The “converter0” plugin device is used for convert the S16_BE format to S16_LE for the wm8960 PCM audio.   Select one device as AVB talker, and run: $ speaker-test -p 25000 -F S16_BE -c 2 -r 48000 -D aaf0   Select one device as AVB listener, and run: $ arecord -F 25000 -t raw -f S16_BE -c 2 -r 48000 -D aaf0 | aplay -F 25000 -t raw -f S16_BE -c 2 -r 48000 -D converter0   You can hear the sound on the listener device.   You can also check which qdisc queue is used for AAF by: $ tc -s qdisc   4.2.        Gstreamer AAF audio Select one device as AVB talker, and run: $ gst-launch-1.0 clockselect. \( clock-id=realtime audiotestsrc samplesperbuffer=12 is-live=true ! audio/x-raw,format=S16BE,channels=2,rate=48000 ! avtpaafpay mtt=50000000 tu=1000000 streamid=0xAABBCCDDEEFF000B processing-deadline=0 ! avtpsink ifname=eth0.5 address=06:98:c0:22:df:35 priority=3 processing-deadline=0 \)   Select one device as AVB listener, and run: $ gst-launch-1.0 clockselect. \( clock-id=realtime avtpsrc ifname=eth0.5 ! avtpaafdepay streamid=0xAABBCCDDEEFF000B ! queue max-size-bytes=0 max-size-buffers=0 max-size-time=0 ! audioconvert ! audioresample !  alsasink device="hw:0,0" \)   5.  Packet sniffer Use tcpdump on board to dump the L2 ethernet packet: $ tcpdump -i eth0 ether proto 0x22f0 -w dump.pcap The AVTP ether protocol code is 0x22f0 embedded inside the ether frame, or you can use "vlan 5" VLAN id for tcpdump parameters to dump. Then open this dump.pcap in the windows/Linux PC by the wireshark tool, it will automatically show the protocol inside the package, it can also parser the IEEE1722 (AVTP) CVF/AFF package header as below:   To measure the package latency from transmit port (talker) to receive port (listener), you can use the tcpdump on both end-points. And compare the Epoch Time the packet dumped: "Epoch Time: 1596252905.688243000 seconds". The delta of the epoch time of the same packet is around 100us~500us. This latency actually includes the AF_PACKET clone cost in kernel netfilter, also the tcpdump application schedule latency.   6.  Revision history summarizes the changes done to this document since the initial release. Table2. Revision history Revision number Date Substantive changes 1 5/2021 Initial release    

This is a detailed programming aid for the registers associated with i.MX 8M (m850D) DDR initialization.  For more details, refer to the main mScale DDR tools page: https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-MX-8M-Family-DDR-Tool-Release/ta-p/1104467 Please note that this page is only intended to store the RPA spreadsheets. For questions, please create a new community thread.

Important: If you have any questions or would like to report any issues with the DDR tools or supporting documents please create a support ticket in the i.MX community. Please note that any private messages or direct emails are not monitored and will not receive a response.   These are the detailed programming aids for the registers associated with MMDC DDR3 and LPDDR2 initialization for the MX6DQ SoC. The last sheet formats the register settings for use with ARM RealView ICE. It can also be used with the windows executable for the DDR Stress Test. This programming aid was used for internal NXP boards.  

This is the procedure and patch to set up Ubuntu 12.04 64bit Linux Host PC and building i.MX28 L2.6.35_1.1.0_130130.  It has been tested to build GNOME profile and with FSL Standard MM codec. A) Basic Requirement: Set up the Linux Host PC using ubuntu-12.04.3-desktop-amd64.iso Make sure the previous LTIB installation and the /opt/freescale have been removed B) Installed the needed packages to the Linux Host PC $ sudo apt-get update $ sudo apt-get install gettext libgtk2.0-dev rpm bison m4 libfreetype6-dev $ sudo apt-get install libdbus-glib-1-dev liborbit2-dev intltool $ sudo apt-get install ccache ncurses-dev zlib1g zlib1g-dev gcc g++ libtool $ sudo apt-get install uuid-dev liblzo2-dev $ sudo apt-get install tcl dpkg $ sudo apt-get install asciidoc texlive-latex-base dblatex xutils-dev $ sudo apt-get install texlive texinfo $ sudo apt-get install ia32-libs libc6-dev-i386 lib32z1 $ sudo apt-get install uboot-mkimage $ sudo apt-get install scrollkeeper $ sudo apt-get install gparted $ sudo apt-get install nfs-common nfs-kernel-server $ sudo apt-get install git-core git-doc git-email git-gui gitk $ sudo apt-get install meld atftpd C) Unpack and install the LTIB source package and assume done on the home directory: $ cd ~ $ tar -zxvf L2.6.35_1.1.0_130130_source.tar.gz $ ./L2.6.35_1.1.0_130130_source/install After that, you will find ~/ltib directory created D) Apply the patch to make L2.6.35_1.1.0 could be installed and compiled on Ubuntu 12.04 64bit OS $ cd ~/ltib $ git apply 0001_make_L2.6.35_1.1.0_130130_compile_on_ubuntu_12.04_64bit_OS.patch a) The patch modifies the following files:    dist/lfs-5.1/base_libs/base_libs.spec    dist/lfs-5.1/lkc/lkc.spec    dist/lfs-5.1/mux_server/mux_server.spec    dist/lfs-5.1/ncurses/ncurses.spec b) Add the following files to the pkgs directory:    pkgs/lkc-1.4-lib.patch    pkgs/lkc-1.4-lib.patch.md5 E) Then, it is ready to proceed the rest of the LTIB env setup process: $ cd ~/ltib $ ./ltib -m config $ ./ltib Reference: L2.6.35_1.1.0_130130_docs/doc/mx28/Setting_Up_LTIB_Host_on_Ubuntu_9_04.pdf https://community.freescale.com/docs/DOC-93394 https://community.freescale.com/message/332385#332385 https://community.freescale.com/thread/271675 https://community.freescale.com/message/360556#360556 scrollkeeper is for the gnome-desktop compilation NOTE: When compiling gstreamer, this warning was pop up.  Just ignore it seems okay.

The system controller timer service is responsible for: Watchdog - The watchdog resource is managed by the SCU. The SCFW exposes a "virtual" watchdog to all CPUs. This virtual watchdog is managed by software and it is based on a low power timer, the SCU also features a physical watchdog timer that is used to ensure the correct operation of the device. Some of the features implemented by this watchdog service are: - Update of the watchdog timeout - Start/stop of the watchdog - Refresh of the watchdog - Return of the watchdog status such as maximum watchdog timeout that can be set, watchdog timeout interval, and watchdog timeout interval remaining. Since this is usually handled by the OS itself no examples are provided in this guide. Real Time Clock (RTC) - The SCFW is responsible for providing access to the RTC. The features supported by the API are: - Set/get time - Setting alarms Only the partition that owns the SC_R_SYSTEM resource is allowed to set the time, alarms and calibration values for the RTC. All other partitions are able to read the RTC time.  Here is an example on setting the RTC from the M4 side: struct time_date{ uint16_t year; uint8_t month; uint8_t day; uint8_t hour; uint8_t min; uint8_t sec; } rtc_time; sc_err_t sc_status; sc_ipc_t ipc; /* Open IPC channel */ sc_status = sc_ipc_open(&ipc, SC_IPC_AP_CH0); if(sc_status != SC_ERR_NONE) printf("Error opening Inter Processor Channel\n"); /* Initialize RTC */ /* Hard code RTC time to January 5th 2018 at 12:00 hours */ sc_status = sc_timer_set_rtc_time(ipcHandle, 2018, 1, 5, 12, 0, 0); if(sc_status != SC_ERR_NONE) printf("Error initializing RTC. \r\n"); /* Return time */ sc_status = sc_timer_get_rtc_time(ipcHandle, &(rtc_time.year), &(rtc_time.month), &(rtc_time.day), &(rtc_time.hour), &(rtc_time.min), &(rtc_time.sec)); printf("Year: %d, Month: %d, Day: %d, Hour: %d, Minutes: %d, Seconds: %d. \r\n", rtc_time.year, rtc_time.month, rtc_time.day, rtc_time.hour, rtc_time.min, rtc_time.sec);‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ https://community.nxp.com/docs/DOC-342654 

According to iMX6DQRM chapter 46 (On-Chip OTP Controller), the UID field is located at offsets 0x410 and 0x420 from the base address of the OCOTP.  That is: OTP Bank0 Word1 - contains the first word of the UID OTP Bank0 Word2 - contains the second word of the UID. md.l 21bc410 021bc410: d72d7372 d72d7372 d72d7372 d72d7372    rs-.rs-.rs-.rs-. 021bc420: 906709d4 906709d4 906709d4 906709d4 ..g...g...g...g. Comparing to the read information under Linux shell: cat /proc/cpuinfo ......... Serial : 906709d4d72d7372 The value is identical from uboot and linux kernel reading back.

A tutorial on 'Freescale Yocto Project'. Source code is located here NOTE: When doing 'repo init -u .... -b <LATEST_STABLE_BRANCH_NAME>', make sure you are using the latest stable branch (dora is the latest when writing this note)

When to enable CONFIG_DEBUG_LL, choose the debug port and then CONFIG_EARLY_PRINTK on i.MX6, system will hang. There is no error information there as below, Uncompressing Linux... done, booting the kernel. Booting Linux on physical CPU 0x0 Initializing cgroup subsys cpu Initializing cgroup subsys cpuacct Linux version 4.1.15-00001-gd582989-dirty (jay@jay-ubuntu) (gcc version 4.9 20 150123 (prerelease) (GCC) ) #10 SMP PREEMPT Mon Jul 17 15:08:55 CST 2017 CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c53c7d CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache Machine model: Freescale i.MX6 Quad SABRE Smart Device Board bootconsole [earlycon0] enabled cma: Reserved 448 MiB at 0x2a000000 Memory policy: Data cache writealloc -------------- hang -----------------‍‍‍‍‍‍‍‍‍‍‍‍‍ The patch fix it on android n7.1.1_1.0.0, kernel: 4.1.15.

   Some of Chinese customer couldn’t normally download android source code from google site, here give a way to download android source from Mirror site of Tsinghua University. Customers in other areas can refer to the configurations of ubuntu 18.04 in the document. Updating software packages for ubuntu18.04 LTS 1、Using software updater to update software packages Press Install Now button to update software. Restart ubuntu18.04 2、Installing necessary software packages #sudo apt-get install flex # sudo apt-get install bison # sudo apt-get install gperf # sudo apt-get install build-essential # sudo apt-get install zlib1g-dev # sudo apt-get install lib32ncurses5-dev # sudo apt-get install x11proto-core-dev # sudo apt-get install libx11-dev # sudo apt-get install lib32z1-dev # sudo apt-get install libgl1-mesa-dev # sudo apt-get install tofrodos # sudo apt-get install python-markdown # sudo apt-get install libxml2-utils # sudo apt-get install xsltproc # sudo apt-get install uuid-dev:i386 liblzo2-dev:i386 # sudo apt-get install gcc-multilib g++-multilib # sudo apt-get install subversion # sudo apt-get install openssh-server openssh-client # sudo apt-get install uuid uuid-dev # sudo apt-get install zlib1g-dev liblz-dev # sudo apt-get install liblzo2-2 liblzo2-dev # sudo apt-get install lzop # sudo apt-get install git-core curl # sudo apt-get install u-boot-tools # sudo apt-get install mtd-utils # sudo apt-get install android-tools-fsutils # sudo apt-get install openjdk-8-jdk # sudo apt-get install device-tree-compiler # sudo apt-get install aptitude # sudo aptitude install libcurl4-openssl-dev nss-updatedb 3、Downloading and unpacking Android release package https://www.nxp.com/products/processors-and-microcontrollers/applications-processors/i.mx-applications-processors/android-os-for-i.mx-applications-processors:IMXANDROID?tab=Design_Tools_Tab --O8.1.0_1.3.0_ANDROID_SOURCE_8MQ_GA File name is imx-o8.1.0_1.3.0_8m.tar.gz # cd ~ # tar xzvf imx-o8.1.0_1.3.0_8m.tar.gz Downloading android8.1.0-1.3.0 source code Getting repo # cd ~ # mkdir bin # cd bin # curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo # chmod a+x ~/bin/repo # export PATH=${PATH}:~/bin   Modifying repo File Open ~/bin/repo file with 'gedit' and Change google address From REPO_URL = 'https://gerrit.googlesource.com/git-repo' To REPO_URL = 'https://mirrors.tuna.tsinghua.edu.cn/git/git-repo/' 3、Setting email address # git config --global user.email "[email protected]" # git config --global user.name "xxxx" [ Email & Name should be yours] 4、Modifying android setup script and Running it Open ~/ imx-o8.1.0_1.3.0_8m /imx_android_setup.sh and add a line like below: ...       if [ "$rc" != 0 ]; then          echo "---------------------------------------------------"          echo "-----Repo Init failure"          echo "---------------------------------------------------"          return 1       fi find -name 'aosp-O8.1.0-1.3.0.xml'| xargs perl -pi -e 's|https://android.googlesource.com/|https://aosp.tuna.tsinghua.edu.cn/|g' fi   # Don't Delete .repo directory and hidden files #rm -rf $android_builddir/.??* ... Then save it and exit. # cd ~/ # source ~/ imx-o8.1.0_1.3.0_8m/imx_android_setup.sh Then android_build directory is created at ~/ # export MY_ANDROID=~/android_build          48 hours later: Compiling android8.1.0-1.3.0 BSP # cd ~/android_build # gedit ./prebuilts/sdk/tools/jack-admin               And find “JACK_SERVER_COMMAND” ,change it to be: JACK_SERVER_COMMAND="java -XX:MaxJavaStackTraceDepth=-1 -Djava.io.tmpdir=$TMPDIR $JACK_SERVER_VM_ARGUMENTS -Xmx4096m -cp $LAUNCHER_JAR $LAUNCHER_NAME"          Save and exit. And run: # ./prebuilts/sdk/tools/jack-admin stop-server # ./prebuilts/sdk/tools/jack-admin start-server # export ARCH=arm64 # export CROSS_COMPILE=~/android_build/prebuilts/gcc/linux-x86/aarch64/aarch64-linuxandroid-4.9/bin/aarch64-linux-android- # export LC_ALL=C # source build/envsetup.sh # lunch evk_8mq-userdebug               Begin to build android BSP for i.MX8MQ # make –j4 NXP TIC weidong sun 2018-08-15

Update 2 Nov 2016: The work begun with this current sensor board has been superseded by this 4-channel solution. The ribbon cables used below, although easier to solder, were very stiff and tended to lift the sensors off the double sticky foam tape, which endangered the target application board. This post remains for historical purposes. This little board set was put together quickly to measure run current as well as sleep current. The sensor board is intended to be affixed with double sided tape to the board under test. A flat ribbon cable connects to the connection board where the power and current sensor connections may be made. The holes accommodate banana jacks. The current range is selected via the dip switch on the connection board. Below is an image of the schematic. The attached PDF contains the schematic, layout and partial Digikey parts lists along with embedded source files (look for the thumb-tacks).   The DMN1019USN FETs have a Vgs of 8V, which limits the maximum current which may be measured (currents above will starve the output of the current sensor amplifiers since the output cannot swing high enough). With a supply of ~7.5V, a maximum high current of ~3A is possible with the 2V/A gain (A4) version of the INA250. With a 2 Ohm shunt for the low current range, the maximum current with an INA212 (1000V/V gain) is ~3mA. Two FETs in parallel were used to decrease the series resistance when shorting the low current shunt. [NOTE: The voltage applied to the gates of the FETs assumes that the ground on the both board under test and the current sense board combo are in common.  An isolated supply could have been used but was not for simplicity.] The high current range is intended for normal operation, i.e., measuring run currents.The low current range should only be selected once the board is configured for a low power mode. Once in that mode, the low power mode may be selected.  To use an instrumented target board without having to have the connection board hooked up and powered, jump the two vias (spaced 0.1", labeled "Jump" by the current input connections). These vias short the 2 Ohm low current shunt resistor. The target board is connected via the 3-pin header. The outer two points are the negative input connection; the center is the positive. Two negative connections are provided to avoid having to cross the connection wires. These wires should be kept as short as possible. The series resistance at the input in the high range (dip switch off) was under 25mOhms, so the connections wires only add to that. The board set may be used as-is before snapping apart since connections between the boars runs through the row of snap-vias. A ribbon cable needs be used after snapping them apart. Finer pitch ribbon could have been used but it'd be much less friendly for hand soldering. Board sets in multiples of 3 may be ordered here. Here are some photos of the prototype board (some silk screen errors and the banana jack holes were drilled too small). Before snapping apart on the left and after with the ribbon cable and connectors added on the right. Here is a photo of the i.MX6SL on the EVK instrumented for low-power sleep-mode current measurement on VDD_HIGH_IN: SENSOR CALIBRATION CHECK: The calibration of three sensor boards was checked by forcing an accurate, known current with a Keysight B2902A Source Measure Unit (SMU). The average sensor output was measured for each forced current in the high and low range. The data was plotted and best fit lines were applied: The data for each sensor was very linear. The coefficients and offsets of all 6 best fit lines were very similar as can be seen above. The data can be perused in the attached Excel file (HiLo-sensors-1-3-calib.xlsx). The three sets of coefficients for the high range sensor (the INA250A4) were averaged. For each sensor's output, the current was calculated using these averaged coefficients and tabulated next to the forced current (the brown data). All of the calculated currents were within at most 20mA of the actual current forced by the SMU. TO DO: Two outputs are somewhat cumbersome; it'd be handier to just switch which sensor is outputting to the measurement device. It'd also be really handy to have a 4 channel distribution board and 4 sensor boards, which would allow the use of a 4 channel oscilloscope. Some LEDs on the distribution board indicating which measurement range is in use would also be nice... UPDATE 7 OCT 2016: Working now on a Kinetis-based, data-logging capable, 4-channel power profiler for run and sleep. The Kinetis ADCs will be used to measure the sensor outputs and power supply rail voltages, which should be fine given the level of accuracy that is required. Data is sent up the line in real time via a USB serial port, which opens the possibility of the target board profiling it's own power consumption, including low power modes (a wake-up line for the target board is provided for just that purpose). For more information on current measurements in general, see this tutorial series: A Current Sensing Tutorial--Part 1: Fundamentals | EE Times  A Current Sensing Tutorial-Part II: Devices | EE Times  A Current Sensing Tutorial--Part III: Accuracy | EE Times  A Current Sensing Tutorial-Part IV: Layout and Troubleshooting Guidelines | EE Times 

Instruction On Linux OS, we have two major audio system API to play/record audio pcm, alsa-lib and pulseaudio. Pulseaudio is in Freescale Ubuntu root fs release, while alsa-lib is used by default in LTIB release. This article is to tell how to configure alsa-lib by configuration file. Architecture Alsa-lib has a set of standard API which allows application to develop easily. At the same time, it provides a scalable mechanism to fulfill its features, including resample, channels remix, sound mixing from different applications, and so on. As above figure describes, alsa plugin provide fundamental function, and the whole pipeline makes customization possible. Alsa-lib API pretend to be an alsa device and provide a name for caller to open. What kind of plugin the name represents for is decided by configuration. For example, pcm.card0 {    type hw    card 0 } card0 is the fake alsa device name, with type hw, which represents for the first real alsa device. pcm.plug {     @args [ SLAVE ]     @args.SLAVE {         type string     }     type plug     slave.pcm $SLAVE } plug is the fake alsa device name, with type plug, which represents for audio conversion processor. In addition, it's also receive arguments from application that make it more flexible. When we call snd_pcm_open(.., "plug:card0",..); in the application, we create a pipeline which will first convert the source pcm to sound card 0 capable pcm if necessary in "plug" plugin, then play it to sound card 0 in "card0" plugin.  "slave.pcm" is the key to link different plugins. The number of arguments could be more than one, with definition pcm.xxx {     @args [ arg1 arg2 arg3 ]     @args.arg1 { type string }     @args.arg2 { type string }     @args.arg3 { type string }     ... } The argument could also have default value, please refer to /usr/share/alsa/alsa.conf. To pass the arguments, use snd_pcm_open(.., "xxx:arg1,arg2,arg3",..); From the name, we can always follow the pipeline to the last plugin, which type might be hw(to alsa driver), file(to file), or others (pulse, bluetooth...) to network, protocol stack and so on. The Configuration Files In configuration file, we mainly define the fake alsa device name. The root configuration file is /usr/share/alsa/alsa.conf, which will load additional configuration files which might overwrite previous name definition in the previously loaded file. The load sequence is: 1. /usr/share/alsa/alsa.conf 2. /usr/share/alsa/alsa.conf.d/* 3. /etc/asound.conf for administrator 4. $(HOME)/.asoundrc for certain user In practice, alsa applications (e.g. aplay or speaker-test) are always using "default" as the fake device name, so that the most important thing to customize your own pipeline is to overwirte "default". For example, pcm.dmix_44100{     type dmix     ipc_key 5678293     ipc_key_add_uid yes     slave{         pcm "hw:0,0"         period_time 10000         format S16_LE         rate 44100     } } pcm.!default{     type plug     route_policy "average"     slave.pcm "tee:dmix_44100,/home/wayne/a.pcm" } The "!" in "pcm.!default" means forcing overwrite. The pipeline defined above is as following figure: The next example is the "default" definition on ubuntu root fs. pcm.!default {     type pulse     hint {         show on         description "Playback/recording through the PulseAudio sound server"     } } The only alsa plugin is "pulse", and the pipeline is as following: Additional Resources There are a lot of alsa plugins developed, with various configuration parameters, I won't list them in detail. Please refer to .asoundrc - ALSA wiki for more details.