From f90dc6c1212ce9c6884c7cb2214ea7bde1ab18e7 Mon Sep 17 00:00:00 2001
From: Daniel Samson <12231216+daniel-samson@users.noreply.github.com>
Date: Wed, 22 Jul 2026 20:49:07 +0100
Subject: [PATCH] =?UTF-8?q?reorg:=20begin=20library/protocol/=20=E2=80=94?=
 =?UTF-8?q?=20move=20block=20+=20usb-transfer?=
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Start the protocol tree: wire protocols move to library/protocol/<name>/,
entry file <name>-protocol.zig, module name unchanged. block and usb-transfer
are pure moves — every consumer already imports them by module name, so only
the b.addModule paths change and the empty system/services/block/ is removed.

  block-protocol         -> library/protocol/block/block-protocol.zig
  usb-transfer-protocol  -> library/protocol/usb-transfer/usb-transfer-protocol.zig

zig build + test green.
---
 build.zig                                                 | 4 ++--
 .../protocol/block/block-protocol.zig                     | 0
 .../protocol/usb-transfer}/usb-transfer-protocol.zig      | 0
 system/services/device-manager/device-manager.zig         | 8 ++++++++
 4 files changed, 10 insertions(+), 2 deletions(-)
 rename system/services/block/protocol.zig => library/protocol/block/block-protocol.zig (100%)
 rename {system/drivers/usb-xhci-bus => library/protocol/usb-transfer}/usb-transfer-protocol.zig (100%)

diff --git a/build.zig b/build.zig
index 562938a..e609877 100644
--- a/build.zig
+++ b/build.zig
@@ -314,12 +314,12 @@ pub fn build(b: *std.Build) void {
     // driver to drive its device (open / control / interrupt / bulk). A protocol
     // module like vfs-protocol, shared by the bus driver and every class driver.
     const usb_transfer_protocol_module = b.addModule("usb-transfer-protocol", .{
-        .root_source_file = b.path("system/drivers/usb-xhci-bus/usb-transfer-protocol.zig"),
+        .root_source_file = b.path("library/protocol/usb-transfer/usb-transfer-protocol.zig"),
     });
     // The block-device protocol: read/write of fixed-size blocks, spoken between a
     // filesystem and a block driver (usb-storage). A protocol module like the rest.
     const block_protocol_module = b.addModule("block-protocol", .{
-        .root_source_file = b.path("system/services/block/protocol.zig"),
+        .root_source_file = b.path("library/protocol/block/block-protocol.zig"),
     });
 
     // Kernel tunables (maximum_cpus, stack sizes, tick rate). A dependency-free module of
diff --git a/system/services/block/protocol.zig b/library/protocol/block/block-protocol.zig
similarity index 100%
rename from system/services/block/protocol.zig
rename to library/protocol/block/block-protocol.zig
diff --git a/system/drivers/usb-xhci-bus/usb-transfer-protocol.zig b/library/protocol/usb-transfer/usb-transfer-protocol.zig
similarity index 100%
rename from system/drivers/usb-xhci-bus/usb-transfer-protocol.zig
rename to library/protocol/usb-transfer/usb-transfer-protocol.zig
diff --git a/system/services/device-manager/device-manager.zig b/system/services/device-manager/device-manager.zig
index 0623b99..fd4c000 100644
--- a/system/services/device-manager/device-manager.zig
+++ b/system/services/device-manager/device-manager.zig
@@ -42,6 +42,13 @@ const virtio_gpu_pci_class: u64 = pci_class.ClassCode.pack(.{
     .prog_if = 0,
 });
 
+
+const vga_compatible_gpu_pci_class: u64 = pci_class.ClassCode.pack(.{
+    .base = @intFromEnum(pci_class.BaseClass.display),
+    .subclass = @intFromEnum(pci_class.display.SubClass.vga_compatible),
+    .prog_if = 0,
+});
+
 /// The driver that serves a *reported* PCI function (M19.3: matching moved
 /// from the boot snapshot to the bus reports), or null. A machine can carry
 /// several identical controllers — one driver instance per reported device,
@@ -49,6 +56,7 @@ const virtio_gpu_pci_class: u64 = pci_class.ClassCode.pack(.{
 fn pciDriverForIdentity(identity: u64) ?[]const u8 {
     return switch (identity) {
         xhci_pci_class => "/system/drivers/usb-xhci-bus",
+        vga_compatible_gpu_pci_class => "/system/drivers/display",
         virtio_gpu_pci_class => "/system/drivers/virtio-gpu",
         else => null,
     };