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VIM4 OS Boot Priority
VIM4 is capable of boot-up from: eMMC, TF Card, SPI-Flash
We talking there only about 1st stage SOC boot,
next second stage OS loading possible for any other devices like USB storage's,
NVMe etc … and depends from u-boot configurations
Default boot priority
- TF-Card always have highest priority
- eMMC
- SPI-Flash
U-boot shell usage
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 reset via MCU, or you can reboot the hardware by clicking the Reset button, or plugging the power supply or cable.
need reboot device by RESET button or re-plug power cable or power-off device or reboot via mcu
Linux command-line usage
i2cset -f -y 6 0x18 0x20 1 # setup default eMMC boot-mode
i2cset -f -y 6 0x18 0x20 0 # setup SPI-flash boot-mode
Hot apply setting changes via mcu reboot
i2cset -f -y 6 0x18 0x91 1
OOWOW boot special shortcut
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