Kernel: root partition is now passed from the commandline

disk.sh

@@ -30,14 +30,9 @@ sed -e 's/\s*\([-\+[:alnum:]]*\).*/\1/' << EOF | fdisk $DISK_NAME
   t     # set type
   2     # ... of partition 2
   20    # Linux filesystem
-  x		# expert menu
-  n		# partition name
-  3		# ... of partition 3
-  mount-test
-  n		# partition name
-  2		# ... of partition 2
-  banan-root
-  r		# back to main menu
+  t     # set type
+  3     # ... of partition 3
+  20    # Linux filesystem
   w     # write changes
 EOF
 
@@ -63,16 +58,16 @@ sudo grub-install --no-floppy --target=i386-pc --modules="normal ext2 multiboot"
 
 echo -e '
 menuentry "banan-os" {
-	multiboot /boot/banan-os.kernel
+	multiboot /boot/banan-os.kernel root=/dev/hda1
 }
 menuentry "banan-os (no serial)" {
-	multiboot /boot/banan-os.kernel noserial
+	multiboot /boot/banan-os.kernel root=/dev/hda1 noserial
 }
 menuentry "banan-os (no apic)" {
-	multiboot /boot/banan-os.kernel noapic
+	multiboot /boot/banan-os.kernel root=/dev/hda1 noapic
 }
 menuentry "banan-os (no apic, no serial)" {
-	multiboot /boot/banan-os.kernel noapic noserial
+	multiboot /boot/banan-os.kernel root=/dev/hda1 noapic noserial
 }
 ' | sudo tee ${MOUNT_DIR}/boot/grub/grub.cfg
 

kernel/include/kernel/FS/VirtualFileSystem.h

@@ -12,7 +12,7 @@ namespace Kernel
 	class VirtualFileSystem : public FileSystem
 	{
 	public:
-		static BAN::ErrorOr<void> initialize();
+		static BAN::ErrorOr<void> initialize(BAN::StringView);
 		static VirtualFileSystem& get();
 		virtual ~VirtualFileSystem() {};
 

kernel/kernel/FS/VirtualFileSystem.cpp

@@ -12,7 +12,7 @@ namespace Kernel
 
 	static VirtualFileSystem* s_instance = nullptr;
 
-	BAN::ErrorOr<void> VirtualFileSystem::initialize()
+	BAN::ErrorOr<void> VirtualFileSystem::initialize(BAN::StringView root)
 	{
 		ASSERT(s_instance == nullptr);
 		s_instance = new VirtualFileSystem();
@@ -20,8 +20,13 @@ namespace Kernel
 			return BAN::Error::from_errno(ENOMEM);
 		BAN::ScopeGuard guard([] { delete s_instance; s_instance = nullptr; } );
 
-		auto partition_inode = TRY(DeviceManager::get().read_directory_inode("hda1"));
+		if (root.size() < 5 || root.substring(0, 5) != "/dev/")
+			return BAN::Error::from_c_string("root must be in /dev/");
+		root = root.substring(5);
+
+		auto partition_inode = TRY(DeviceManager::get().read_directory_inode(root));
 		s_instance->m_root_fs = TRY(Ext2FS::create(*(Partition*)partition_inode.ptr()));
+
 		TRY(s_instance->mount(&DeviceManager::get(), "/dev"));
 
 		guard.disable();
@@ -76,7 +81,7 @@ namespace Kernel
 
 		const auto path_parts = TRY(path.split('/'));
 
-		for (const auto& path_part : path_parts)
+		for (auto path_part : path_parts)
 		{
 			if (path_part.empty() || path_part == "."sv)
 			{

kernel/kernel/kernel.cpp

@@ -27,14 +27,13 @@ struct ParsedCommandLine
 {
 	bool force_pic		= false;
 	bool disable_serial	= false;
+	BAN::StringView root;
 };
 
-ParsedCommandLine ParseCommandLine()
+static bool should_disable_serial()
 {
-	ParsedCommandLine result;
-
 	if (!(g_multiboot_info->flags & 0x02))
-		return result;
+		return false;
 
 	const char* start = g_kernel_cmdline;
 	const char* current = g_kernel_cmdline;
@@ -42,12 +41,8 @@ ParsedCommandLine ParseCommandLine()
 	{
 		if (!*current || *current == ' ' || *current == '\t')
 		{
-			if (current - start == 6 && memcmp(start, "noapic", 6) == 0)
-				result.force_pic = true;
-
 			if (current - start == 8 && memcmp(start, "noserial", 8) == 0)
-				result.disable_serial = true;
-
+				return true;
 			if (!*current)
 				break;
 			start = current + 1;
@@ -55,7 +50,28 @@ ParsedCommandLine ParseCommandLine()
 		current++;
 	}
 
-	return result;
+	return false;
+}
+
+static ParsedCommandLine cmdline;
+
+static void parse_command_line()
+{
+	if (!(g_multiboot_info->flags & 0x02))
+		return;
+
+	BAN::StringView full_command_line(g_kernel_cmdline);
+	auto arguments = MUST(full_command_line.split(' '));
+
+	for (auto argument : arguments)
+	{
+		if (argument == "noapic")
+			cmdline.force_pic = true;
+		else if (argument == "noserial")
+			cmdline.disable_serial = true;
+		else if (argument.size() > 5 && argument.substring(0, 5) == "root=")
+			cmdline.root = argument.substring(5);
+	}
 }
 
 struct Test
@@ -87,8 +103,7 @@ extern "C" uintptr_t g_userspace_end;
 
 extern void userspace_entry();
 
-void init2(void*);
-void device_updater(void*);
+static void init2(void*);
 
 extern "C" void kernel_main()
 {
@@ -96,9 +111,7 @@ extern "C" void kernel_main()
 
 	DISABLE_INTERRUPTS();
 
-	auto cmdline = ParseCommandLine();
-
-	if (!cmdline.disable_serial)
+	if (!should_disable_serial())
 		Serial::initialize();
 	if (g_multiboot_magic != 0x2BADB002)
 	{
@@ -119,6 +132,9 @@ extern "C" void kernel_main()
 	MMU::intialize();
 	dprintln("MMU initialized");
 
+	parse_command_line();
+	dprintln("command line parsed, root='{}'", cmdline.root);
+
 	PCI::initialize();
 	dprintln("PCI initialized");
 
@@ -189,16 +205,7 @@ extern "C" void kernel_main()
 	ASSERT(false);
 }
 
-void device_updater(void*)
-{
-	while (true)
-	{
-		Kernel::DeviceManager::get().update();
-		PIT::sleep(1);
-	}
-}
-
-void init2(void* tty1_ptr)
+static void init2(void* tty1_ptr)
 {
 	using namespace Kernel;
 	using namespace Kernel::Input;
@@ -207,7 +214,7 @@ void init2(void* tty1_ptr)
 
 	DeviceManager::initialize();
 
-	MUST(VirtualFileSystem::initialize());
+	MUST(VirtualFileSystem::initialize(cmdline.root));
 
 	if (auto res = PS2Controller::initialize(); res.is_error())
 		dprintln("{}", res.error());