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diff --git a/user/bsps/arm/imxrt.rst b/user/bsps/arm/imxrt.rst index 6dacfd9..30b1437 100644 --- a/user/bsps/arm/imxrt.rst +++ b/user/bsps/arm/imxrt.rst @@ -1,29 +1,48 @@ .. SPDX-License-Identifier: CC-BY-SA-4.0 -.. Copyright (C) 2020 embedded brains GmbH +.. Copyright (C) 2020 embedded brains GmbH & Co. KG .. Copyright (C) 2020 Christian Mauderer imxrt (NXP i.MXRT) ================== -This BSP offers only one variant, the `imxrt1052`. This variant supports the -i.MXRT 1052 processor on a IMXRT1050-EVKB (tested with rev A1). You can also -configure it to work with custom boards. +This BSP offers multiple variants. The `imxrt1052` supports the i.MXRT 1052 +processor on a IMXRT1050-EVKB (tested with rev A1). Some possibilities to adapt +it to a custom board are described below. NOTE: The IMXRT1050-EVKB has an backlight controller that must not be enabled without load. Make sure to either attach a load, disable it by software or disable it by removing the 0-Ohm resistor on it's input. +The `imxrt1166-cm7-saltshaker` supports an application specific board. Adapting +it to another i.MXRT1166 based board works similar like for the `imxrt1052` BSP. + Build Configuration Options --------------------------- Please see the documentation of the `IMXRT_*` and `BSP_*` configuration options for that. You can generate a default set of options with:: - ./waf bsp_defaults --rtems-bsps=arm/imxrt1052 > config.ini + ./waf bspdefaults --rtems-bsps=arm/imxrt1052 > config.ini -Boot Process ------------- +Adapting to a different board +----------------------------- + +This is only a short overview for the most important steps to adapt the BSP to +another board. Details for most steps follow further below. + +#. The device tree has to be adapted to fit the target hardware. +#. A matching clock configuration is necessary (simplest method is to generate + it with the NXP PinMux tool) +#. The `dcd_data` has to be adapted. That is used for example to initialize + SDRAM. +#. `imxrt_flexspi_config` has to be adapted to match the Flash connected to + FlexSPI (if that is used). +#. `BOARD_InitDEBUG_UARTPins` should be adapted to match the used system + console. + +Boot Process of IMXRT1050-EVKB +------------------------------ There are two possible boot processes supported: @@ -39,7 +58,7 @@ For programming the HyperFlash in case 1, you can use the on board debugger integrated into the IMXRT1050-EVKB. You can generate a flash image out of a compiled RTEMS application with for example:: - arm-rtems6-objcopy -O binary build/arm/imxrt1052/testsuites/samples/hello.exe hello.bin + arm-rtems@rtems-ver-major@-objcopy -O binary build/arm/imxrt1052/testsuites/samples/hello.exe hello.bin Then just copy the generated binary to the mass storage provided by the debugger. Wait a bit till the mass storage vanishes and re-appears. After that, @@ -82,34 +101,36 @@ ones that need different values): You can find the default definitions in `bsps/arm/imxrt/start/flash-*.c`. Take a look at the `i.MX RT1050 Processor Reference Manual, Rev. 4, 12/2019` chapter -`9.7 Program image` for details about the contents. +`9.7 Program image` or `i.MX RT1166 Processor Reference Manual, Rev. 0, 05/2021` +chapter `10.7 Program image` for details about the contents. FDT --- The BSP uses a FDT based initialization. The FDT is linked into the application. -You can find the default FDT used in the BSP in -`bsps/arm/imxrt/dts/imxrt1050-evkb.dts`. The FDT is split up into two parts. The -core part is put into an `dtsi` file and is installed together with normal -headers into `${PREFIX}/arm-rtems6/imxrt1052/lib/include`. You can use that to +You can find the default FDT used in the BSPs in `bsps/arm/imxrt/dts`. The FDT +is split up into two parts. The controller specific part is put into an `dtsi` +file. The board specific one is in the dts file. Both are installed together +with normal headers into +`${PREFIX}/arm-rtems@rtems-ver-major@/${BSP}/lib/include`. You can use that to create your own device tree based on that. Basically use something like:: /dts-v1/; - + #include <imxrt/imxrt1050-pinfunc.h> #include <imxrt/imxrt1050.dtsi> - + &lpuart1 { pinctrl-0 = <&pinctrl_lpuart1>; status = "okay"; }; - + &chosen { stdout-path = &lpuart1; }; - + /* put your further devices here */ - + &iomuxc { pinctrl_lpuart1: lpuart1grp { fsl,pins = < @@ -117,43 +138,25 @@ create your own device tree based on that. Basically use something like:: IMXRT_PAD_GPIO_AD_B0_13__LPUART1_RX 0x13000 >; }; - + /* put your further pinctrl groups here */ }; You can then convert your FDT into a C file with (replace `YOUR.dts` and similar -with your FDT source names):: +with your FDT source names): + +.. code-block:: none - sh> arm-rtems6-cpp -P -x assembler-with-cpp \ - -I ${PREFIX}/arm-rtems6/imxrt1052/lib/include \ - -include "YOUR.dts" /dev/null | \ - dtc -O dtb -o "YOUR.dtb" -b 0 -p 64 + sh> arm-rtems@rtems-ver-major@-cpp -P -x assembler-with-cpp \ + -I ${PREFIX}/arm-rtems@rtems-ver-major@/imxrt1052/lib/include \ + -include "YOUR.dts" /dev/null | \ + dtc -O dtb -o "YOUR.dtb" -b 0 -p 64 sh> rtems-bin2c -A 8 -C -N imxrt_dtb "YOUR.dtb" "YOUR.c" You'll get a C file which defines the `imxrt_dtb` array. Make sure that your new C file is compiled and linked into the application. It will overwrite the existing definition of the `imxrt_dtb` in RTEMS. -PLL Settings ------------- - -The commercial variant of the i.MXRT1052 on the evaluation board allows a clock -up to 600MHz for the ARM core. For some industrial variants only up to 528MHz -are specified. To make it possible to adapt to these variants the application -can overwrite the following constant: - -.. code-block:: c - - #include "fsl_clock_config.h" - - const clock_arm_pll_config_t armPllConfig_BOARD_BootClockRUN = { - .loopDivider = 100, - .src = 0, - }; - -With the default configuration of a 24MHz oscillator, the loopDivider has to be -88 for the 528MHz. - Clock Driver ------------ @@ -195,10 +198,38 @@ Note that the SPI-pins on the evaluation board are shared with the SD card. Populate R278, R279, R280, R281 on the IMXRT1050-EVKB (Rev A) to use the SPI pins on the Arduino connector. +By default, the native chip selects are used. If you want to use GPIOs as chip +select instead, you can use the `cs-gpios` and `num-cs` attributes just like on +a Linux SPI controller. A maximum of `IMXRT_LPSPI_MAX_CS` pins can be used. + +The hardware doesn't support selecting no native chip select during a transfer. +Therefore one native chip select has to be reserved as a dummy if you want to be +able to use GPIOs. The pin function for this chip select must not be configured +on any pin. Dummy will be the first of the first four chip selects that is not a +native one. Example configuration:: + + &lpspi4 { + status = "okay"; + pinctrl-0 = <&my_pinctrl_lpspi4>; + cs-gpios = <0>, <0>, <&gpio1 1 0>, <0>, <&gpio11 5 1>; + num-cs = <5>; + } + +In this case, CS2 will be the dummy chip select and no pin must be configured +with that function. CS0, CS1 and CS3 are just native chip selects and should be +used via pin functions. GPIO1.1 is used as a high active CS and GPIO11.5 a low +active one. + Limitations: * Only a basic SPI driver is implemented. This is mostly a driver limitation and not a hardware one. +* GPIO CS pins on i.MXRT10xx are not tested. The chip has a lot of errate so + they might not work. +* Switching from one mode (CPOL/CPHA) to another one can lead to single wrong + edges on the CLK line if GPIO CS pins are involved. Make sure to stuff a dummy + transfer with `SPI_NO_CS` set if you use multiple modes together with a GPIO + CS. Network Interface Driver ------------------------ @@ -222,13 +253,58 @@ the SDK. But please note that they are not tested and maybe won't work out of the box. Everything that works with interrupts most likely needs some special treatment. -Caveats -------- +The SDK files are imported to RTEMS from the NXP mcux-sdk git repository that +you can find here: https://github.com/nxp-mcuxpresso/mcux-sdk/ + +The directory structure has been preserved and all files are in a +`bsps/arm/imxrt/mcux-sdk` directory. All patches to the files are marked with +`#ifdef __rtems__` markers. + +The suggested method to import new or updated files is to apply all RTEMS +patches to the mcux-sdk repository, rebase them to the latest mcux-sdk release +and re-import the files. The new base revision should be mentioned in the commit +description to make future updates simpler. + +A import helper script (that might or might not work on newer releases of the +mcux-sdk) can be found here: +https://raw.githubusercontent.com/c-mauderer/nxp-mcux-sdk/d21c3e61eb8602b2cf8f45fed0afa50c6aee932f/export_to_RTEMS.py + +Clocks and SDRAM +---------------- The clock configuration support is quite rudimentary. The same is true for SDRAM. It mostly relies on the DCD and on a static clock configuration that is taken from the NXP SDK example projects. -The MPU settings are currently quite permissive. +If you need to adapt the DCD or clock config to support a different hardware, +you should generate these files using the NXP MCUXpresso Configuration Tools. +You can add the generated files to your application to overwrite the default +RTEMS ones or you can add them to RTEMS in a new BSP variant. + +As a special case, the imxrt1052 BSP will adapt it's PLL setting based on the +chip variant. The commercial variant of the i.MXRT1052 will use a core clock of +600MHz for the ARM core. The industrial variants only uses 528MHz. For other +chip or BSP variants, you should adapt the files generated with the MCUXpresso +Configuration Tools. + +Caveats +------- + +* The MPU settings are currently quite permissive. + +* There is no power management support. + +* On the i.MXRT1166, sleeping of the Cortex M7 can't be disabled even for + debugging purposes. That makes it hard for a debugger to access the + controller. To make debugging a bit easier, it's possible to overwrite the + idle thread with the following one in the application: + + .. code-block:: c -There is no power management support. + void * _CPU_Thread_Idle_body(uintptr_t ignored) + { + (void)ignored; + while (true) { + /* void */ + } + } |