Boot from floppy, boot from HD,
— Kieran Bingham (@kieranbingham) October 5, 2019
Boot from network, boot from CD,
Boot from SD, even boot from USB.
Boot from HDMI… wait, come again? https://t.co/sRQSI72KLc
(courtesy of @Superna9999 )
It’s not really « boot from HDMI » the bootROM will fetch 8bytes from the HDMI ddc link from a non-standard i2c address and offset to force a specific boot mode (Usb, sdcard, eMMC, nand, SPI) for debug purposes
— Neil Armstrong (@Superna9999) October 5, 2019
https://github.com/superna9999/linux/wiki/Amlogic-HDMI-Boot-Dongle
Firmware Security 