readme.txt
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2Technexion i.MX8M Pico board
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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