boot: make bare/base driver-manager + netstack non-blocking; changelog

Base submodule 1f826240: 00_pcid-spawner (/usr) and 10_smolnetd base-default
init units switched to oneshot_async so init never blocks the boot-to-login
path on PCI driver enumeration or a network adapter binding. Adds the
2026-07-16 CHANGELOG entry (mini login restored, kernel MSR #GP guard,
build-system staleness/lock/override fixes).

CHANGELOG.md

@@ -6,6 +6,63 @@ When a commit changes the visible system surface, supported hardware, build flow
 or major documentation status, add a short note here and keep the README "What's New" section in
 sync with the newest highlights.
 
+## 2026-07-16 — Boot path restored: Mini ISO reaches a working login prompt
+
+### Boot / init (the login blockers)
+
+- **base-env no longer hangs the boot.** `00_base.service` ran a full `zsh`
+  as an init oneshot; zsh's interactive startup hangs in the oneshot before
+  the login stack. Switched to `mkdir` (uutils). An earlier "echo/mkdir also
+  hang" result was a false negative — a silent config `[[files]]` override
+  (`redbear-legacy-base.toml` shadowing `base.toml`) was still running zsh.
+- **ptyd no longer blocks init.** `00_ptyd.service` was `type = "notify"`,
+  but ptyd signals readiness via its scheme cap fd (`ready_sync_scheme`), so
+  init waited on a readiness byte that never came and blocked forever at
+  ptyd. Corrected to `type = { scheme = "pty" }` (base recipe default +
+  `redbear-mini` override).
+- **Driver-manager + netstack no longer wedge the boot.** The post-switchroot
+  `/usr` `00_pcid-spawner.service` was a blocking oneshot (init waited for
+  every PCI driver to reach readiness) and `10_smolnetd.service` was
+  `type = "notify"` (blocks until a NIC binds). Both are now `oneshot_async`;
+  the login path renders on the initfs framebuffer and needs neither ready
+  first. (The initfs driver spawner stays blocking — disk must mount.)
+
+### Kernel
+
+- **Root can no longer panic the kernel via `/scheme/sys/msr`.** A bad MSR
+  write (e.g. cpufreqd's legacy P-state MSR, unsupported under KVM) raised a
+  kernel-mode `#GP` on the raw `wrmsr`, which was unrecoverable and panicked
+  the whole machine (`unreachable!()` in `exit_this_context`). Added
+  `wrmsr_safe`/`rdmsr_safe` with `#GP` fault recovery (the same labeled-region
+  mechanism as usercopy page-fault recovery); the MSR scheme and the cross-CPU
+  MSR IPI handler now return `EIO` instead of faulting.
+
+### Noise
+
+- hwd ACPI `_LNK` interrupt-routing enumeration (50+ INFO lines per boot on
+  QEMU) demoted to `debug`.
+
+### Build system
+
+- **Host fstools staleness fixed** — `make live`'s `redox_installer`/`redoxfs`
+  are rebuilt when their sources change (the `build/fstools` dir target had no
+  source prerequisite, so edits silently never reached image assembly).
+- **Prefix no longer rebuilds every build** — `make prefix` is a no-op tarball
+  extract, so `libc.a`'s mtime never advanced past the fork commit; now stamped
+  after a successful prefix step.
+- **Concurrent-build lock** (`flock`) prevents two builds corrupting caches.
+- **Config `[[files]]` overrides are now visible** — the installer warns when a
+  later-included config redefines a file path (was a silent last-wins accumulate).
+
+### Status
+
+- **Mini ISO**: boots to the `Red Bear login:` prompt on VT2 (framebuffer) and
+  the serial debug console, verified on q35/KVM both with and without a NIC,
+  zero kernel panics.
+- **Bare ISO**: driver-manager/netstack blocking fixes applied; login bring-up
+  in progress.
+- **Full ISO** (KWin/Wayland `redbear-greeterd`): unchanged, still experimental.
+
 ## 2026-07-01 — Phase I/II complete: full s2idle + S3 entry + LG Gram DMI
 
 ### Phase I.5 (kernel ↔ acpid s2idle wire end-to-end)