1**************************** 2Technexion i.MX8M Pico board 3**************************** 4 5This file documents the Buildroot support for the Technexion i.MX8M 6Pico board. The Pico i.MX8M system-on-module [1] is present in 7development kits like the Pico Pi i.MX8M [2]. 8 9Build 10===== 11 12First, configure Buildroot for the i.MX8M Pico board: 13 14 make imx8mpico_defconfig 15 16Build all components: 17 18 make 19 20You will find in output/images/ the following files: 21 - bl31.bin 22 - boot.vfat 23 - Image 24 - imx8-boot-sd.bin 25 - lpddr4_pmu_train_fw.bin 26 - pico-8m-dcss-ili9881c.dtb 27 - pico-8m.dtb 28 - rootfs.ext4 29 - sdcard.img 30 - signed_hdmi_imx8m.bin 31 - u-boot.imx 32 33Flashing sdcard.img on the eMMC 34=============================== 35 36i.MX8M Pico board does not have a SD card slot. The storage is an 37eMMC. An easy way to flash the eMMC is to use the u-boot ums 38command. The boards are sold pre-flashed with such a u-boot. It is 39assumed here that the board has already a working u-boot on eMMC and 40jumpers are set to boot on eMMC. See [3]. 41 42Jumper configuration for eMMC boot: 43J1: jumper on pins 4 and 6. 44J2: jumper on pins 2 and 4. 45 46In case the board was flashed with a wrong u-boot, or the eMMC is 47erased, u-boot can be loaded by USB Serial Download boot mode, using 48imx-usb-loader. See [3] and [4]. 49 50For flashing: 51- Plug the micro USB cable from the Debug USB Port, to your computer 52- Plug the USB Type C to your computer, this will power up the board 53 54In the U-Boot prompt launch: 55 56=> ums 0 mmc 0 57 58This will mount the eMMC content in the host PC as a mass storage device. 59 60To determine the device associated to the eMMC card have a look in the 61/proc/partitions file: 62 63 cat /proc/partitions 64 65If your system automatically mount some device partitions, make sure 66to unmount them. 67 68Buildroot prepares a bootable "sdcard.img" image in the output/images/ 69directory, ready to be dumped on the eMMC. Launch the following 70command as root: 71 72 dd if=output/images/sdcard.img of=/dev/<your-sd-device> 73 74*** WARNING! This will destroy all the eMMC content. Use with care! *** 75 76This operation can take several minutes, depending on the image 77size. When tested, a 2MB/s transfer rate was observed. 78 79For details about the medium image layout, see the definition in 80board/freescale/common/imx/genimage.cfg.template. 81 82Boot the i.MX8M Pico board 83========================== 84 85To boot your newly created system: 86- put a micro USB cable into the Debug USB Port and connect using a terminal 87 emulator at 115200 bps, 8n1; 88- power on the board, with USB Type C connector. 89 90Enjoy! 91 92[1]. https://www.technexion.com/products/system-on-modules/pico/pico-compute-modules/detail/PICO-IMX8M 93[2]. https://www.technexion.com/products/system-on-modules/pico-evaluation-kits/detail/PICO-PI-IMX8M-BASIC 94[3]. https://www.technexion.com/support/knowledgebase/boot-configuration-settings-for-pico-baseboards/ 95[4]. https://www.technexion.com/support/knowledgebase/loading-bootable-software-images-onto-the-emmc-of-picosom-on-pico-pi/ 96