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by snvzz 967 days ago
>I had to use UART

There's u-boot patches with video and USB support. There's also work in progress UEFI, which already boots Linux fine.

Once these are finalized, you won't need UART. You'll be selecting where to boot or configuring the firmware in the same manner you do on an IBM PC clone.

It will of course still be possible to use the simpler, reliable UART.
1 comments
snvzz 967 days ago
To add to that (edit no longer possible): Selecting boot from SD card via the boot DIP switches is already possible.

This ROM won't even initialize RAM. All it does is fetch next stage from SPI, eMMC, SD or UART (xmodem), into SRAM (CPU cache used as RAM) and jump to it.

What's not possible is USB, as the (non-updatable) early boot code ROM within the SoC is trivial and obviously has no USB support.

Thus UEFI or u-boot are needed for USB or NVME boot.

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