I'm sorry, as surely this is an FAQ but I've spent quite a bit of time troubleshooting and reading. This is very similar to Kevin's thread from May subject 'u-boot devices broken after 2018.4 upgrade, strange u-boot interaction'. In that thread's case, the issue was that interrupt_char was being set to "\n". My symptoms are the same, but interrupt_char is set to " " or "d".

I'm running LAVA from the latest released containers (2018.11), and trying to use a beaglebone-black with a more recent u-boot than exists in validation.l.o. qemu works fine.

The problem seems to be that LAVA thinks there's a prompt when there isn't, and so it sends commands too quickly. Here's example output from the serial console (job link[2]):

U-Boot 2017.07 (Aug 31 2017 - 15:35:58 +0000)

CPU : AM335X-GP rev 2.1 I2C: ready DRAM: 512 MiB No match for driver 'omap_hsmmc' No match for driver 'omap_hsmmc' Some drivers were not found MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1 Net: cpsw, usb_ether Press SPACE to abort autoboot in 10 seconds => => setenv autoload no => setenv initrd_high 0xffffffff => setenv fdt_high 0xffffffff => dhcp link up on port 0, speed 100, full duplex BOOTP broadcast 1 BOOTP broadcast 2 BOOTP broadcast 3 DHCP client bound to address 10.100.0.55 (1006 ms) => 172.28.0.4 Unknown command '172.28.0.4' - try 'help' => tftp 0x82000000 57/tftp-deploy-t7xus3ey/kernel/vmlinuz link up on port 0, speed 100, full duplex *** ERROR: `serverip' not set ...

When I u-boot manually, after I hit SPACE (or 'd', both work), u-boot *deletes* the character and then prints '=> ' (is that delete the root cause?). When LAVA runs, it shows an extra => and starts typing as seen above. dhcp takes a second or two, and so the subsequent command starts to get lost (in the above log we see an IP, because 'setenv serverip' got lost).

If I set boot_character_delay to like 1000, it works because it gives enough time for dhcp to finish before typing the next character, but obviously makes the job very slow, and still not reliable.

I'm out of ideas.. help?

P.S. Two interesting things I've learned recently: 1) boot_character_delay must be specified in device_types file. it's ignored when specified in the device file (surprising, as I see it listed in some people's device files[3]). 2) If you install ser2net from sid, you can set max-connections and do some _very handy_ voyeurism on the serial console while lava does its thing (hat tip Kevin Hilman for that one).

Thanks, Dan

[1] https://lists.lavasoftware.org/pipermail/lava-users/2018-May/001064.html [2] https://lava.therub.org/scheduler/job/57 [3] https://git.linaro.org/lava/lava-lab.git/tree/lkft.validation.linaro.org/mas...