S&T 44011-0208-13-2, User Manual

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pITX-iMX8M – User Guide Rev. 1.4
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7.7. Kontron Bootloader Environment Extensions
To support PITX-iMX8M board properly, Kontron adds some environment variables to the standard set of variables
provided by mainline U-Boot. These variables are shown below.
Table 47: Bootloader Environment Extensions
Variable Value Description
board_name pitx-imx8m
board_serial UTD080002 Board serial number read from KEU EEPROM
cpu armv8 CPU family
eth1addr From I210/I211 iNVM Ethernet port FEC1 MAC address
ethaddr From EEPROM Ethernet port FEC0 MAC address
fdt_addr_r 0x43000000 DTB load address used by distroboot
kernel_addr_r 0x40480000 Kernel load address used by distroboot
pxefile_addr_r 0x40480000 PXE load address as required by distroboot spec.
ramdisk_addr_r 0x44000000 Ramdisk load address used by distroboot
fdtfile pitx-imx8m_hdmi.dtb Default device tree file for the module
hw_rev L130 Board revision read from strappings
scriptaddr 0x40400000 Script file load address used by distroboot
serial# From SoC SoC internal serial number
soc imx8m SoC and SoC type
soc_type imx8mq
vendor kontron
video_off no Enable video by default
Variables from the table above marked in bold are set automatically each time U-Boot
starts. They will override different settings possibly stored in persistent environment.
7.8. Bootloader Mass Storage Support
U-Boot provides support to read and write from mass storage devices like
 QSPI flash
 eMMC device
 SD card
 USB thumb device
7.8.1. QSPI flash
QSPI flash is accessed using the "sf" command
Example: Load one sector (64K) from SPI flash
=> sf probe 0
=> sf read ${loadaddr} 0 10000