This works. I am blown away!
My initial setup:
- Ubuntu 24.04
- FTDI 3.3v ttl serial
- HW-667 USB relay module for controlling power
Claude instructions:
# Router investigation
## Goal
Get Uboot-lantiq to run on the router from TFTP boot.
## Environment
- Ubuntu host (192.168.1.10)
- Router control scripts:
/home/home/src/local_scripts/reboot.py
/home/home/src/local_scripts/enter_tftp.py
- Router TTY terminal is at /tmp/serial-console. It operates at 115200 speed rate.
- Router default ip: 192.168.1.1
- Working directory: ~/router-investigation
- Toolchain directory: ~/src/openwrt
## Safety
- Power cycling is permitted
- Flashing is permitted
## Workflow
- Read next-steps.md at the start of each new session.
- Read findings.md for established facts.
- Save raw logs under logs/ and refer to them by filename.
- Distinguish observed facts, hypotheses, and unverified claims.
- Don't repeat completed tests unless needed to resolve a specific uncertainty.
- Review existing openwrt patch that adds support for DrayBoot Vigor 2860 in here: /home/home/src/patches/26084.patch; Vigor 2862 might be similar
- If changes are needed to uboot-lantiq package, create a new target; we might want to create a patch file later for the new target
After around 2h, around 50 trials, and ~50k tokens I got uboot on the board with no interaction from my end. The AI agent went through:
- toolchain configuration & compilation
- router discovery
- boot process discovery and mapping of registers
- compilation and patching of uboot to make it boot correctly on the device
TFTP detected.
RX: Filename: 'v2862_0.bin'\r
RX: Loading:\r
RX: \rD\rr\ra\ry\rT\re\rk\r \rD\rr\ra\ry\rT\re\rk\r \rD\r
RX: done\r
RX: Transferred = 524548 (0x80104) Bytes\r
RX: Got .bin file\r
RX: >> CodeStart=0x80024000\r
RX: Go~~\r
RX: \r
RX: \r
RX: U-Boot 2013.10-openwrt4 (Oct 25 2026 - 14:46:18) Vigor2862\r
RX: \r
RX: Board: DrayTek Vigor 2862\r
RX: Unknown partnum: 11\r
RX: SoC: Lantiq v1.1\r
RX: CPU: 600 MHz\r
RX: IO: 300 MHz\r
RX: BUS: 300 MHz\r
RX: BOOT: unknown\r
RX: DRAM: 128 MiB\r
RX: Using default environment\r
RX: \r
RX: In: serial\r
RX: Out: serial\r
RX: Err: serial\r
RX: Vigor2862 #
