drivers: log devices.csv columns + friendly labels for all buses

Each bus's discovery line now prints the device's would-be /etc/devices.csv row
(bus, base, class, prog_if, vendor, device, subsystem / hid) in uppercase hex,
followed by the human-readable names — so a row for a new driver reads straight
off the boot log, for pci, usb, and acpi alike.

- pci-bus: logFunction moved to registerAndReport (where vendor/device/subsystem
  are read from config space) and reformatted to columns + names; subsystem
  prints '*' when the function has none. Read unclaimed via the bridge ECAM, so
  no per-function claim is needed.
- usb-xhci-bus, acpi: the same column framing on their existing discovery lines.
- qemu_test.py: the acpi-ps2 and acpi-report regexes updated to the new ACPI
  format (both verified passing in QEMU).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KJqSiLLchDUUCoXn5jsiwd

system/drivers/pci-bus/pci-bus.zig

@@ -21,19 +21,20 @@ const logging = @import("logging");
 const device_manager_protocol = @import("device-manager-protocol");
 const pci_class = @import("pci-class");
 
-/// Log a discovered function with its (class / subclass / prog-IF) triple decoded
-/// to human names — the boot-log breadcrumb that says *what* the hardware is, so
-/// "class 0x01 (Mass Storage Controller) subclass 0x06 (Serial ATA Controller)
-/// progif 0x01 (AHCI 1.0)" reads straight off the log when writing a new driver.
-/// A dedicated wider buffer than `writeLine`'s, since the decoded names are long.
-fn logFunction(bus: u64, dev: u64, function: u64, class_triple: u32) void {
+/// Log a discovered function as its would-be /etc/devices.csv columns (bus, base,
+/// class, prog_if, vendor, device, subsystem) followed by the human-readable
+/// class/subclass/prog-IF names — so a row for a new driver reads straight off the
+/// boot log. `subsystem` prints as `*` when the function has none, matching the CSV
+/// wildcard. All read unclaimed, through the bridge's ECAM: the enumerator never
+/// claims the functions it probes (pci.zig's header — the device-owned pci.Function
+/// view is what needs a claim, not this one). A wide buffer: the names are long.
+fn logFunction(bus: u64, dev: u64, function: u64, class_triple: u32, vendor_id: u16, product_id: u16, subsystem: u32) void {
     const cc = pci_class.ClassCode.unpack(@truncate(class_triple));
     const pif = pci_class.progIfName(cc.base, cc.subclass, cc.prog_if);
-    var line: [200]u8 = undefined;
-    const text = if (pif.len != 0)
-        std.fmt.bufPrint(&line, "/system/drivers/pci-bus: {d}:{d}.{d} class 0x{x:0>2} ({s})  subclass 0x{x:0>2} ({s})  progif 0x{x:0>2} ({s})\n", .{ bus, dev, function, cc.base, pci_class.className(cc.base), cc.subclass, pci_class.subclassName(cc.base, cc.subclass), cc.prog_if, pif }) catch return
-    else
-        std.fmt.bufPrint(&line, "/system/drivers/pci-bus: {d}:{d}.{d} class 0x{x:0>2} ({s})  subclass 0x{x:0>2} ({s})  progif 0x{x:0>2}\n", .{ bus, dev, function, cc.base, pci_class.className(cc.base), cc.subclass, pci_class.subclassName(cc.base, cc.subclass), cc.prog_if }) catch return;
+    var sub_buffer: [8]u8 = undefined;
+    const sub = if (subsystem == 0) "*" else std.fmt.bufPrint(&sub_buffer, "{X:0>8}", .{subsystem}) catch "*";
+    var line: [320]u8 = undefined;
+    const text = std.fmt.bufPrint(&line, "/system/drivers/pci-bus: {d}:{d}.{d}  bus=pci base={X:0>2} class={X:0>2} prog_if={X:0>2} vendor={X:0>4} device={X:0>4} subsystem={s}  —  {s} / {s}{s}{s}\n", .{ bus, dev, function, cc.base, cc.subclass, cc.prog_if, vendor_id, product_id, sub, pci_class.className(cc.base), pci_class.subclassName(cc.base, cc.subclass), if (pif.len != 0) " / " else "", pif }) catch return;
     _ = logging.write(text);
 }
 
@@ -136,7 +137,6 @@ fn scan() void {
                 if (vendor_device & 0xFFFF == 0xFFFF) continue;
                 const class_revision = configRead(bus, dev, function, 0x08);
                 found += 1;
-                logFunction(bus, dev, function, class_revision >> 8);
                 registerAndReport(bus, dev, function, class_revision >> 8);
             }
         }
@@ -221,6 +221,10 @@ fn registerAndReport(bus: u64, dev: u64, function: u64, class_triple: u32) void
         configWrite16(bus, dev, function, 0x04, command);
     }
 
+    // The devices.csv-column + friendly-name breadcrumb, now that vendor/device/
+    // subsystem are read. Every discovered function is logged, matched or not.
+    logFunction(bus, dev, function, class_triple, descriptor.vendor, descriptor.device, descriptor.subsystem);
+
     const registered = device.register(bridge_id, &descriptor) orelse {
         std.log.info("register refused for {d}:{d}.{d}", .{ bus, dev, function });
         return;

system/drivers/usb-xhci-bus/usb-xhci-bus.zig

@@ -390,13 +390,16 @@ fn reportInterface(manager: ipc.Handle, port: u32, interface: library.InterfaceI
         std.log.info("child report for port {d} interface {d} failed", .{ port, interface.number });
         return null;
     };
-    std.log.info("port {d} interface {d}: {s} ({d}/{d}/{d}) registered as device {d}", .{
+    // The devices.csv columns (bus=usb, and the class triple as base/class/prog_if)
+    // then the human-readable interface name — a would-be /etc/devices.csv row read
+    // straight off the boot log.
+    std.log.info("port {d} interface {d}  bus=usb base={X:0>2} class={X:0>2} prog_if={X:0>2}  —  {s}  registered as device {d}", .{
         port,
         interface.number,
-        usb_ids.interfaceName(interface.class, interface.subclass, interface.protocol),
         interface.class,
         interface.subclass,
         interface.protocol,
+        usb_ids.interfaceName(interface.class, interface.subclass, interface.protocol),
         registered,
     });
     return registered;

system/services/acpi/acpi.zig

@@ -214,11 +214,13 @@ fn onInit(endpoint: ipc.Handle) bool {
     while (i < registered_count) : (i += 1) {
         const entry = registered[i];
         const hid = entry.hid[0..entry.hid_len];
+        // The devices.csv columns (bus=acpi, hid) then the human-readable name — a
+        // would-be /etc/devices.csv row read straight off the boot log.
         const desc = acpi_ids.description(hid);
         if (desc.len != 0)
-            std.log.info("reported {s} (device {d}, {d} resources) — {s}", .{ hid, entry.device_id, entry.resource_count, desc })
+            std.log.info("device {d}  bus=acpi hid={s}  —  {s}  ({d} resources)", .{ entry.device_id, hid, desc, entry.resource_count })
         else
-            std.log.info("reported {s} (device {d}, {d} resources)", .{ hid, entry.device_id, entry.resource_count });
+            std.log.info("device {d}  bus=acpi hid={s}  ({d} resources)", .{ entry.device_id, hid, entry.resource_count });
         if (manager) |h| {
             var report = device_manager_protocol.ChildAdded{ .bus = @intFromEnum(device_manager_protocol.BusKind.acpi), .parent = node_id, .bus_address = entry.device_id, .identity = 0, .device_id = entry.device_id };
             @memcpy(report.hid[0..entry.hid_len], entry.hid[0..entry.hid_len]);