| .. _pico_pi: |
| |
| Pico-Pi i.MX7D - Android Things IoT Development Platform |
| ############################################################# |
| |
| Overview |
| ******** |
| |
| The i.MX7D SoC is a Hybrid multi-core processor composed of Single Cortex A7 |
| core and Single Cortex M4 core. |
| Zephyr was ported to run on the M4 core. In a later release, it will also |
| communicate with the A7 core (running Linux) via RPmsg. |
| |
| |
| .. image:: pico_pi.jpg |
| :align: center |
| :alt: Pico-Pi i.MX7D |
| |
| Hardware |
| ******** |
| |
| The Pico-Pi Platform is composed of a CPU and IO board. |
| |
| Pico-Pi IO Board |
| ================ |
| - S1 - On/Off (MX7_ONOFF signal) |
| - Board to board connector : Edison compatible connector (70 configurable pins) |
| - mikroBUS expansion connector ADC, GPIO, I²C, PWM, SPI, UART) |
| - 10-pin needle JTAG Connector |
| - Debug USB exposing One UART |
| - MIPI DSI 1 lane Connector |
| - LCD Touch Connector |
| - Audio Jack: Mic and Stereo Headphone |
| |
| Pico-Pi CPU Board |
| ================= |
| |
| - CPU i.MX7 Dual with a Single Cortex A7 (1 GHz) core and |
| Single Cortex M4 (200MHz) core |
| - Memory |
| |
| - RAM -> A7: 4GB |
| - RAM -> M4: 3x32KB (TCML, TCMU, OCRAM_S), 1x128KB (OCRAM) and 1x256MB (DDR) |
| - Flash -> A7: 8GB eMMC |
| |
| For more information about the i.MX7 SoC and Pico-Pi i.MX7D, see these references: |
| |
| - `i.MX 7 Series Website`_ |
| - `i.MX 7 Dual Datasheet`_ |
| - `i.MX 7 Dual Reference Manual`_ |
| |
| Supported Features |
| ================== |
| |
| The Pico-Pi i.MX7D configuration supports the following hardware features on the |
| Cortex M4 Core: |
| |
| +-----------+------------+-------------------------------------+ |
| | Interface | Controller | Driver/Component | |
| +===========+============+=====================================+ |
| | NVIC | on-chip | nested vector interrupt controller | |
| +-----------+------------+-------------------------------------+ |
| | SYSTICK | on-chip | systick | |
| +-----------+------------+-------------------------------------+ |
| | GPIO | on-chip | gpio | |
| +-----------+------------+-------------------------------------+ |
| | I2C | on-chip | i2c | |
| +-----------+------------+-------------------------------------+ |
| | UART | on-chip | serial port-polling; | |
| | | | serial port-interrupt | |
| +-----------+------------+-------------------------------------+ |
| |
| The default configuration can be found in the defconfig file: |
| :zephyr_file:`boards/technexion/pico_pi/pico_pi_mcimx7d_m4_defconfig` |
| |
| Other hardware features are not currently supported by the port. |
| |
| Connections and IOs |
| =================== |
| |
| The Pico-Pi board Board was tested with the following pinmux controller |
| configuration. |
| |
| +---------------+---------------------+--------------------------------+ |
| | Board Name | SoC Name | Usage | |
| +===============+=====================+================================+ |
| | UART_TX232 | UART1_TX | UART Console | |
| +---------------+---------------------+--------------------------------+ |
| | UART_RX232 | UART1_RX | UART Console | |
| +---------------+---------------------+--------------------------------+ |
| | RX_E | UART6_TX | UART (mikroBUS and Edison) | |
| +---------------+---------------------+--------------------------------+ |
| | TX_E | UART6_RX | UART (mikroBUS and Edison) | |
| +---------------+---------------------+--------------------------------+ |
| | I2CX_SDA_3V | I2C1_SDA | I2C (mikroBUS and Edison) | |
| +---------------+---------------------+--------------------------------+ |
| | I2CX_SCL_3V | I2C1_SCL | I2C (mikroBUS and Edison) | |
| +---------------+---------------------+--------------------------------+ |
| |
| System Clock |
| ============ |
| |
| The M4 Core is configured to run at a 200 MHz clock speed. |
| |
| Serial Port |
| =========== |
| |
| The iMX7D SoC has seven UARTs. The number 6 is configured for the console and |
| the number 2 is used in the mikroBUS connector. |
| |
| Programming and Debugging |
| ************************* |
| |
| The Pico-Pi i.MX7D doesn't have QSPI flash for the M4 and it needs to be started by |
| the A7 core. The A7 core is responsible to load the M4 binary application into |
| the RAM, put the M4 in reset, set the M4 Program Counter and Stack Pointer, and |
| get the M4 out of reset. |
| The A7 can perform these steps at bootloader level or after the Linux system |
| has booted. |
| |
| The M4 can use up to 5 different RAMs. These are the memory mapping for A7 and |
| M4: |
| |
| +------------+-----------------------+------------------------+-----------------------+----------------------+ |
| | Region | Cortex-A7 | Cortex-M4 (System Bus) | Cortex-M4 (Code Bus) | Size | |
| +============+=======================+========================+=======================+======================+ |
| | DDR | 0x80000000-0xFFFFFFFF | 0x80000000-0xDFFFFFFF | 0x10000000-0x1FFEFFFF | 2048MB (less for M4) | |
| +------------+-----------------------+------------------------+-----------------------+----------------------+ |
| | OCRAM | 0x00900000-0x0091FFFF | 0x20200000-0x2021FFFF | 0x00900000-0x0091FFFF | 128KB | |
| +------------+-----------------------+------------------------+-----------------------+----------------------+ |
| | TCMU | 0x00800000-0x00807FFF | 0x20000000-0x20007FFF | | 32KB | |
| +------------+-----------------------+------------------------+-----------------------+----------------------+ |
| | TCML | 0x007F8000-0x007FFFFF | | 0x1FFF8000-0x1FFFFFFF | 32KB | |
| +------------+-----------------------+------------------------+-----------------------+----------------------+ |
| | OCRAM_S | 0x00180000-0x00187FFF | 0x20180000-0x20187FFF | 0x00000000-0x00007FFF | 32KB | |
| +------------+-----------------------+------------------------+-----------------------+----------------------+ |
| |
| References |
| ========== |
| |
| - `i.MX 7 Dual Reference Manual`_ from page 182 (section 2.1.2 and 2.1.3) |
| - `Toradex Wiki`_ |
| |
| |
| At compilation time you have to choose which RAM will be used. This |
| configuration is done in the file :zephyr_file:`boards/technexion/pico_pi/pico_pi_mcimx7d_m4.dts` with |
| "zephyr,flash" (when CONFIG_XIP=y) and "zephyr,sram" properties. The available |
| configurations are: |
| |
| .. code-block:: none |
| |
| "zephyr,flash" |
| - &ddr_code |
| - &tcml_code |
| - &ocram_code |
| - &ocram_s_code |
| - &ocram_pxp_code |
| - &ocram_epdc_code |
| |
| "zephyr,sram" |
| - &ddr_sys |
| - &tcmu_sys |
| - &ocram_sys |
| - &ocram_s_sys |
| - &ocram_pxp_sys |
| - &ocram_epdc_sys |
| |
| |
| Below you will find the instructions to load and run Zephyr on M4 from A7 using |
| u-boot. |
| |
| Connect both micro USB interfaces into the PC. This is the A7 console and the |
| UART6 in the Edison connector is M4 console for Zephyr with both configured to work at 115200 8N1. |
| The USB interface is used to power the CPU and IO boards and is connected |
| to the USB OTG interface of the i.MX7D. |
| |
| After powering up the platform stop the u-boot execution on the A7 core and |
| expose the eMMC as mass storage with the following command in the u-boot |
| prompt: ``ums 0 mmc 0``. Copy the compiled zephyr.bin to the first FAT |
| partition and remove the mounted device on the PC by issuing a "Ctrl+C" in the |
| u-boot prompt. |
| Set the u-boot environment variables and run the zephyr.bin from the |
| appropriated memory configured in the Zephyr compilation: |
| |
| .. code-block:: console |
| |
| setenv bootm4 'fatload mmc 0:1 $m4addr $m4fw && dcache flush && bootaux $m4addr' |
| # TCML |
| setenv m4tcml 'setenv m4fw zephyr.bin; setenv m4addr 0x007F8000' |
| setenv bootm4tcml 'run m4tcml && run bootm4' |
| run bootm4tcml |
| # TCMU |
| setenv m4tcmu 'setenv m4fw zephyr.bin; setenv m4addr 0x00800000' |
| setenv bootm4tcmu 'run m4tcmu && run bootm4' |
| run bootm4tcmu |
| # OCRAM |
| setenv m4ocram 'setenv m4fw zephyr.bin; setenv m4addr 0x00900000' |
| setenv bootm4ocram 'run m4ocram && run bootm4' |
| run bootm4ocram |
| # OCRAM_S |
| setenv m4ocrams 'setenv m4fw zephyr.bin; setenv m4addr 0x00180000' |
| setenv bootm4ocrams 'run m4ocrams && run bootm4' |
| run bootm4ocrams |
| # DDR |
| setenv m4ddr 'setenv m4fw zephyr.bin; setenv m4addr 0x80000000' |
| setenv bootm4ddr 'run m4ddr && run bootm4' |
| run bootm4ddr |
| |
| :ref:`build_an_application` and :ref:`application_run` for more details). |
| |
| References |
| ========== |
| |
| - `Loading Code on Cortex-M4 from Linux for the i.MX 6SoloX and i.MX 7Dual/7Solo Application Processors`_ |
| - `J-Link iMX7D Instructions`_ |
| |
| .. _i.MX 7 Series Website: |
| https://www.nxp.com/products/processors-and-microcontrollers/applications-processors/i.mx-applications-processors/i.mx-7-processors:IMX7-SERIES?fsrch=1&sr=1&pageNum=1 |
| |
| .. _i.MX 7 Dual Datasheet: |
| https://www.nxp.com/docs/en/data-sheet/IMX7DCEC.pdf |
| |
| .. _i.MX 7 Dual Reference Manual: |
| https://www.nxp.com/webapp/Download?colCode=IMX7DRM |
| |
| .. _J-Link Tools: |
| https://www.segger.com/downloads/jlink/#J-LinkSoftwareAndDocumentationPack |
| |
| .. _NXP iMX7D Connect CortexM4.JLinkScript: |
| https://wiki.segger.com/images/8/86/NXP_iMX7D_Connect_CortexM4.JLinkScript |
| |
| .. _Loading Code on Cortex-M4 from Linux for the i.MX 6SoloX and i.MX 7Dual/7Solo Application Processors: |
| https://www.nxp.com/docs/en/application-note/AN5317.pdf |
| |
| .. _J-Link iMX7D Instructions: |
| https://wiki.segger.com/IMX7D |
| |
| .. _Toradex Wiki: |
| https://developer.toradex.com/knowledge-base/freertos-on-the-cortex-m4-of-a-colibri-imx7#Memory_areas |