From 0628944b1560d9308ded23a46be4801e4ded6089 Mon Sep 17 00:00:00 2001
From: Daniel Samson <12231216+daniel-samson@users.noreply.github.com>
Date: Mon, 13 Jul 2026 03:32:37 +0100
Subject: [PATCH] Docs: close the discovery migration (M20.3)
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discovery.md records ACPI enumeration leaving the kernel; device-manager.md
increment 8 marked done — enumeration now runs entirely in ring 3.
---
 docs/device-manager.md |  6 ++++--
 docs/discovery.md      | 14 ++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/docs/device-manager.md b/docs/device-manager.md
index b28d998..2b50bc9 100644
--- a/docs/device-manager.md
+++ b/docs/device-manager.md
@@ -136,8 +136,10 @@ published exit events, signals + `runtime.process`). On top of those:
    the mouse and keyboard QEMU already hangs off it.
 7. **App surface**: `enumerate`/`subscribe` over IPC; `device_enumerate` retreats
    to a manager-internal seam.
-8. **Discovery migration**: pci-bus driver first, acpi service second, kernel scan
-   retired last. (AML-in-user-space is its own track.)
+8. **Discovery migration** — DONE (M19–M20, 2026-07-13): pci-bus driver (M19)
+   then the acpi service (M20) moved enumeration to ring 3; the kernel seeds
+   only the host bridge and the acpi-tables node. See
+   [m19-m20-plan.md](m19-m20-plan.md).
 
 ## Settled questions (2026-07-12)
 
diff --git a/docs/discovery.md b/docs/discovery.md
index 6dad24b..94a0579 100644
--- a/docs/discovery.md
+++ b/docs/discovery.md
@@ -177,3 +177,17 @@ window). The per-function walk moved to the ring-3 `pci-bus` driver
 ECAM scan through its mmio grant, and `device_register`s what it finds, which
 the device manager mirrors and matches. The ACPI namespace walk follows in M20;
 the static tables (MADT, HPET, MCFG, FADT + `\\_S5`) stay kernel-side.
+
+## Update (M20.3, 2026-07-13): ACPI enumeration left the kernel too
+
+The kernel no longer folds the AML namespace's Device objects into the device
+tree. It still parses the *static* tables (MADT for SMP, HPET for the tick, MCFG
+for the host bridge, FADT) and still builds the AML namespace — but only to read
+the `\\_S5` sleep type for poweroff. Device discovery is the ring-3 **acpi
+service** ([device-manager.md](device-manager.md)): it claims the `acpi-tables`
+node the kernel publishes (the AML blobs, a broad io_port grant, the SCI),
+re-parses the same blobs with the shared AML module, evaluates `_STA`/`_CRS`,
+and registers + reports each `_HID` device — the device manager matches drivers
+(ps2-bus) from those reports. With M19's pci-bus driver, discovery now runs
+entirely in user space; the kernel seeds only the host bridge and the
+acpi-tables node.