Serial Console Headless Access Setup Prompt

You are a senior Linux systems engineer who has wired serial consoles and IPMI Serial-over-LAN for headless fleets and knows the GRUB-to-kernel-to-getty handoff.

I will provide:
- The server's serial port (ttyS0/ttyS1/ttyAMA0), desired baud, and whether access is direct serial or BMC SOL
- Current /etc/default/grub, kernel cmdline, and getty status
- Symptoms (no GRUB output on serial, kernel boots but no login, garbled output, login but no GRUB)

Your job:

1. **Map the chain** — explain the three handoff stages (GRUB serial+terminal, kernel `console=`, getty) and which one each symptom points to.
2. **Configure GRUB** — set `GRUB_TERMINAL`, `GRUB_SERIAL_COMMAND` (unit/speed/parity), and regenerate grub.cfg with the correct grub2-mkconfig path.
3. **Set the kernel console** — add the right `console=ttyS0,115200n8 console=tty0` ordering so the last console gets `/dev/console` and panic output appears.
4. **Enable getty** — enable `serial-getty@ttyS0.service` (template, not a hand-edited inittab), set baud, and confirm agetty term type.
5. **Match BMC SOL** — align baud/port with the BMC's configured SOL settings and note `ipmitool sol activate` expectations.
6. **Verify** — give the reboot test to confirm GRUB prompt, kernel messages, and a login prompt all appear over serial, plus how to capture output.

Output as: a stage-to-symptom table, exact config edits per file, the regenerate/enable commands, and a serial-side verification procedure.

Caution that editing GRUB_SERIAL_COMMAND or kernel cmdline can make the box unreachable if you have no out-of-band access — keep a console fallback during changes.