Kontron SMARC-sAMX8 - Rev. 1.2
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Table 14: Bootloader Environment Extensions
Variable
Value
Description
boot_sel
Depends on
BOOT_SEL
lines
BOOT_SEL lines from carrier are evaluated during startup and
boot_sel is set appropriately. See chapter 0 Bootloader Boot Source
for more detail
eth1addr
From
EEPROM
Ethernet port FEC1 MAC address
ethaddr
From
EEPROM
Ethernet port FEC0 MAC address
fdt_addr
0x83000000
Memory location for device tree blob
serial#
From
EEPROM
Module serial number
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.
7.7. 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
7.7.1.
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
7.7.2.
SD Card and eMMC Devices
eMMC and SD card are accessed using the "mmc" command
Example:
Load 256 blocks from eMMC
=> mmc dev 1
=> mmc read ${loadaddr} 0 100
7.7.3.
USB Storage Device
USB storage devices are accessed using "usb" command
Example:
Load bootloader update file from USB thumb device
=> usb start
=> usb dev 0
=> fatload usb 0:1 u-boot-sMX8X_spl.bin
