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VIM4 is capable of boot-up from: eMMC
, TF Card
, SPI-Flash
This page mainly introduces about the first-stage SoC boot. The second-stage OS flashing is possible for USB storage and NVMe, which depends on u-boot
configurations
We can swap the boot priority of the eMMC
and SPI-Flash
via the KBI(Khadas Boot Instructions) from u-boot shell
Change boot priority to: TF-Card ⇒ eMMC ⇒ SPI-Flash
kvim4# kbi bootmode w emmc
Change boot priority to: TF-Card ⇒ SPI-Flash ⇒ eMMC
kvim4# kbi bootmode w spi
To make the booting priority swap take effect, you can reboot via mcu, or you can reboot the hardware by clicking the Reset button, or plugging the power supply or cable.
i2cset -f -y 6 0x18 0x20 1 # setup default eMMC boot-mode
i2cset -f -y 6 0x18 0x20 0 # setup SPI-flash boot-mode
i2cset -f -y 6 0x18 0x91 1
Hold FUNCTION
and short press RESET
to force boot OOWOW service from SPI-flash, and skip other boot sources
TF-card slot must be empty