How to see u-boot prompt?

snickerdoodle general
1
I currently supply power to snickerdoodle via the USB port and I assume I should be able to interrupt u-boot if I can get to the console in time to press a key. When I disconnect and reconnect USB power, I also need to restart my terminal program and so I'm not fast enough to catch the u-boot prompt. Pressing the reset button doesn't seem to do anything. Has anyone been able to interrupt u-boot and get to its prompt? Should I be able to do so if I supply power via J2 connector instead of USB port?
2
let it boot up to linux, then do a "reboot" command in linux and then intervene with a keystroke as it goes back to uboot the second time around. You can also adjust the uboot delay.


On Saturday, July 16, 2016 at 1:48:46 PM UTC-7, Edward Wingate wrote:
I currently supply power to snickerdoodle via the USB port and I assume I should be able to interrupt u-boot if I can get to the console in time to press a key. When I disconnect and reconnect USB power, I also need to restart my terminal program and so I'm not fast enough to catch the u-boot prompt. Pressing the reset button doesn't seem to do anything. Has anyone been able to interrupt u-boot and get to its prompt? Should I be able to do so if I supply power via J2 connector instead of USB port?
3
Supplying power from J2 or from the barrel jack on breakyBreaky will boot the board using the default environment so you won't have an opportunity to interrupt U-Boot. Probably the easiest way to prevent booting as normal would be to change the uenvcmd declaration in uEnv.txt. You can remove the run mmc_loadbit; run boot_snickerdoodle specification from this line to prevent the normal boot process from occurring.

On Saturday, July 16, 2016 at 1:48:46 PM UTC-7, Edward Wingate wrote:
I currently supply power to snickerdoodle via the USB port and I assume I should be able to interrupt u-boot if I can get to the console in time to press a key. When I disconnect and reconnect USB power, I also need to restart my terminal program and so I'm not fast enough to catch the u-boot prompt. Pressing the reset button doesn't seem to do anything. Has anyone been able to interrupt u-boot and get to its prompt? Should I be able to do so if I supply power via J2 connector instead of USB port?
4
On Saturday, July 16, 2016 at 2:13:24 PM UTC-7, Rob Barris wrote:
You can also adjust the uboot delay.

Thank you! So obvious in hindsight.