I noticed that the manual (Booting from NVMe Drives — BeagleBoard Documentation) mentioned getting the root fs on NVME, which I did, and it worked.
However, /boot/firmware is still on /dev/mmcblk1p1. Is it possible to boot without any SD-card?
Kind Regards,
Johan Henselmans
Nope, sadly there is no onboard storage to load u-boot.
I should add the only important bit is the 256MB fat partition. So you could move that to a smaller microSD…
Regards,
I wonder, since it is such a small amount of memory, would there be a trick to store it on eeprom and attach and detect it via SPI or I2C, so it could be attached via some kind of HAT?
Kind Regards,
Johan Henselmans
SPI Nor should be possible over the GPIO pins, U-boot supports that but you’re still looking at an external device to boot the firmware from. Are you worried about SD corruption or something like that?
Yes, experience with SD-cards have been mixed. Most of the time they work as long as on-board storage, but when they’re hosed, they’re hosed.
On the other hand, a simple SD-card with only /boot on it should be easy replaceable, and as it is only used once during boot and read-only, it should be OK.
But as I am desiging a (simple) HAT anyway, I might just as well add some eeprom to it.
Do you know where I can find documentation about the GPIO-pins and uboot config?
Regards,
You need to have an SD card to boot. Yes you can add whatever extra storage you like, but u-boot still needs to reside on an SD card as that is where in internal boot rom is looking.
I haven’t checked to datasheet for the CPU to see what boots modes it supports but the boot config pins are on the PCB so you can change the boot mode by removing/adding resistors. Maybe you can change it to something else.
Okay let’s work thru the decoder:
VOUT0_DATAx goes straight to the HDMI framer…
BOOTMODE7…
B7=0: File-system mode.
Chaining B7 to 1, just switches it to raw mode…
So backup Ethernet mode, is a form of bootp/tftp…
5.4.5 Ethernet Boot page 696 : https://www.ti.com/lit/zip/sprujb3
Regards,
