# Next comparison: info logging through kmsg

The [physical info/console comparison](../evidence/mainline-initrd-info-logging/physical-2026-10-05/README.md) produced a fresh kernel and pre-exec init announcement, without systemd startup or login within 180 seconds. Lowering verbosity did not restore observed progress. This leaves the failing instruction unknown.

Read-only inspection of the exact selected systemd 261.2 archive uses the source pin and raw-file hashes in the [preceding source audit](mainline-initrd-info-console-comparison-2026-10-05.md). Pinned [log.c](https://github.com/systemd/systemd/blob/4925d9f07fc697efccd98a93046ff535b8832445/src/basic/log.c) maps kmsg at raw lines1514–1517, opens `/dev/kmsg` at129–139, and closes console on successful backend opening at323–332. Priority-tagged synchronous writes occur at606–619. Its per-emitter limit is200 messages/5 seconds at588. Opening/writing failure or an absent backend can fall back to console at337–340 and822–830. Selecting kmsg therefore does not prove console was unused or delivery succeeded.

The selected [kernel printk source](https://github.com/torvalds/linux/blob/72d3fcf802c45d00b300f25b848a93c3a2bd7c7e/kernel/printk/printk.c) preserves the userspace severity in devkmsg_write; it may discard disabled/rate-limited records. INFO priority6 is eligible under the existing console threshold7, whose filter suppresses severity>=7. Eligibility is source proof, not runtime delivery. Raw references refer to files, not browser extraction numbering.

Change only `rd.systemd.log_target=console` to `rd.systemd.log_target=kmsg`, retaining info, all current p2/24h artifacts, source/config/Image/DT/initrd/init/root/masks/join/marker-free controls and existing verbosity. This produces352 argument and370 literal command bytes. Use typed begin-only `--initrd-info-kmsg-logging`, requiring both existing parent selectors and excluding debug/info-console. Save/restore it with old state defaulting false; reject aliases/types/conflicts before UART. No generic logging editor, tracing, masks, alternate PID1 or rebuild.

After independently reviewed source fixtures, actual artifact qualification and NEW protected recovery, run one180-second passive capture with exact loads/CRCs/printed/live arguments, full private logging and no candidate input on unknown readiness. Record independent recovery or explicit pending NEW reset. A changed boundary shows backend-selection sensitivity, not a blocked console call; silence cannot distinguish earlier setup, backend, filtering, dropped output or scheduling. [Implementation and actual artifact qualification](../evidence/mainline-initrd-info-kmsg-logging/host/README.md) passed independent review. Physical delivery remains **UNVERIFIED**. Ordinary root/panel/glass task5b.5 stays open.

Read-only startup audit additionally finds INFO is the manager default, while [main.c](https://github.com/systemd/systemd/blob/4925d9f07fc697efccd98a93046ff535b8832445/src/core/main.c) later selects journal-or-kmsg and reapplies commandline/environment settings. Explicit kmsg therefore is not fully equivalent to baseline. Console setup and separate status output also remain. If silent, the smallest next discriminator is one unchanged ordinary-baseline repeat, without any rd.systemd.log_* tokens, to check reproducibility before further interventions; that repeat has not been run.