readme.txt
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2Technexion i.MX8M Mini Pico board
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4
5This file documents the Buildroot support for the Technexion i.MX8M
6Mini Pico board. The Pico i.MX8M Mini system-on-module [1] is present
7in development kits like the Pico Pi i.MX8M Mini [2].
8
9Build
10=====
11
12First, configure Buildroot for the i.MX8M Mini Pico board:
13
14 make imx8mmpico_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 - imx8mm-pico-pi.dtb
26 - imx8mm-pico-pi-ili9881c.dtb
27 - imx8mm-pico-pi-sn65dsi84-hj070na.dtb
28 - lpddr4_pmu_train_fw.bin
29 - rootfs.ext2
30 - rootfs.ext4
31 - sdcard.img
32 - u-boot.imx
33
34Flashing sdcard.img on the eMMC
35===============================
36
37i.MX8M Mini Pico board does not have a SD card slot. The storage is an
38eMMC. An easy way to flash the eMMC is to use the u-boot ums
39command. The boards are sold pre-flashed with such a u-boot. It is
40assumed here that the board has already a working u-boot on eMMC and
41jumpers are set to boot on eMMC. See [3].
42
43Jumper configuration for eMMC boot:
44J1: jumper on pins 4 and 6.
45J2: jumper on pins 2 and 4.
46
47In case the board was flashed with a wrong u-boot, or the eMMC is
48erased, u-boot can be loaded by USB Serial Download boot mode, using
49imx-usb-loader. See [3] and [4].
50
51For flashing:
52- Plug the micro USB cable from the Debug USB Port, to your computer
53- Plug the USB Type C to your computer, this will power up the board
54
55In the U-Boot prompt launch:
56
57=> ums 0 mmc 1
58
59This will mount the eMMC content in the host PC as a mass storage device.
60
61To determine the device associated to the eMMC card have a look in the
62/proc/partitions file:
63
64 cat /proc/partitions
65
66If your system automatically mount some device partitions, make sure
67to unmount them.
68
69Buildroot prepares a bootable "sdcard.img" image in the output/images/
70directory, ready to be dumped on the eMMC. Launch the following
71command as root:
72
73 dd if=output/images/sdcard.img of=/dev/<your-sd-device>
74
75*** WARNING! This will destroy all the eMMC content. Use with care! ***
76
77This operation can take several minutes, depending on the image
78size. When tested, a 2MB/s transfer rate was observed.
79
80For details about the medium image layout, see the definition in
81board/freescale/common/imx/genimage.cfg.template.
82
83Boot the i.MX8M Mini Pico board
84===============================
85
86To boot your newly created system:
87- put a micro USB cable into the Debug USB Port and connect using a terminal
88 emulator at 115200 bps, 8n1;
89- power on the board, with USB Type C connector.
90
91Enjoy!
92
93[1]. https://www.technexion.com/products/system-on-modules/pico/pico-compute-modules/detail/PICO-IMX8M-MINI
94[2]. https://www.technexion.com/products/pico-evaluation-kits/detail/PICOPIIMX8MM1GDEV
95[3]. https://www.technexion.com/support/knowledgebase/boot-configuration-settings-for-pico-baseboards/
96[4]. https://www.technexion.com/support/knowledgebase/loading-bootable-software-images-onto-the-emmc-of-picosom-on-pico-pi/
97