From 368f5e979920e9719ebbfe1a8397a70fe2c8973c Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Fri, 16 Aug 2024 22:09:24 +0300
Subject: [PATCH] Kernel: Add command lineoption `nousb` that will disable usb
 controller

---
 kernel/include/kernel/PCI.h |  2 +-
 kernel/kernel/PCI.cpp       |  6 ++++--
 kernel/kernel/kernel.cpp    | 12 +++++++++---
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/kernel/include/kernel/PCI.h b/kernel/include/kernel/PCI.h
index 940fd6fe..4fd88308 100644
--- a/kernel/include/kernel/PCI.h
+++ b/kernel/include/kernel/PCI.h
@@ -139,7 +139,7 @@ namespace Kernel::PCI
 		static void initialize();
 		static PCIManager& get();
 
-		void initialize_devices();
+		void initialize_devices(bool disable_usb);
 
 		template<typename F>
 		void for_each_device(F callback)
diff --git a/kernel/kernel/PCI.cpp b/kernel/kernel/PCI.cpp
index 66c77c3a..828a03b9 100644
--- a/kernel/kernel/PCI.cpp
+++ b/kernel/kernel/PCI.cpp
@@ -177,7 +177,7 @@ namespace Kernel::PCI
 		}
 	}
 
-	void PCIManager::initialize_devices()
+	void PCIManager::initialize_devices(bool disable_usb)
 	{
 		for_each_device(
 			[&](PCI::Device& pci_device)
@@ -215,7 +215,9 @@ namespace Kernel::PCI
 						switch (pci_device.subclass())
 						{
 							case 0x03:
-								if (auto res = USBManager::get().add_controller(pci_device); res.is_error())
+								if (disable_usb)
+									dprintln("USB support disabled, will not initialize {2H}.{2H}.{2H}", pci_device.class_code(), pci_device.subclass(), pci_device.prog_if());
+								else if (auto res = USBManager::get().add_controller(pci_device); res.is_error())
 									dprintln("{}", res.error());
 								break;
 							default:
diff --git a/kernel/kernel/kernel.cpp b/kernel/kernel/kernel.cpp
index 3e84b9f1..de908d96 100644
--- a/kernel/kernel/kernel.cpp
+++ b/kernel/kernel/kernel.cpp
@@ -37,6 +37,7 @@ struct ParsedCommandLine
 	bool force_pic          = false;
 	bool disable_serial     = false;
 	bool disable_smp        = false;
+	bool disable_usb        = false;
 	BAN::StringView console = "tty0"_sv;
 	BAN::StringView root;
 };
@@ -75,6 +76,8 @@ static void parse_command_line()
 			cmdline.disable_serial = true;
 		else if (argument == "nosmp")
 			cmdline.disable_smp = true;
+		else if (argument == "nousb")
+			cmdline.disable_usb = true;
 		else if (argument.size() > 5 && argument.substring(0, 5) == "root=")
 			cmdline.root = argument.substring(5);
 		else if (argument.size() > 8 && argument.substring(0, 8) == "console=")
@@ -199,8 +202,11 @@ static void init2(void*)
 	PCI::PCIManager::initialize();
 	dprintln("PCI initialized");
 
-	MUST(USBManager::initialize());
-	dprintln("USBManager initialized");
+	if (!cmdline.disable_usb)
+	{
+		MUST(USBManager::initialize());
+		dprintln("USBManager initialized");
+	}
 
 	if (ACPI::ACPI::get().enter_acpi_mode(InterruptController::get().is_using_apic()).is_error())
 		dprintln("Failed to enter ACPI mode");
@@ -222,7 +228,7 @@ static void init2(void*)
 
 	// NOTE: PCI devices are the last ones to be initialized
 	//       so other devices can reserve predefined interrupts
-	PCI::PCIManager::get().initialize_devices();
+	PCI::PCIManager::get().initialize_devices(cmdline.disable_usb);
 	dprintln("PCI devices initialized");
 
 	VirtualFileSystem::initialize(cmdline.root);