[boot] Don't use custom UEFI memory types

The UEFI spec specifically calls out memory types with the high bit set
as being available for OS loaders' custom use. However, it seems many
UEFI firmware implementations don't handle this well. (Virtualbox, and
the firmware on my Intel NUC and Dell XPS laptop to name a few.)

So sadly since we can't rely on this feature of UEFI in all cases, we
can't use it at all. Instead, treat _all_ memory tagged as EfiLoaderData
as possibly containing data that's been passed to the OS by the
bootloader and don't free it yet.

This will need to be followed up with a change that copies anything we
need to save and frees this memory.

See: https://github.com/kiznit/rainbow-os/blob/master/boot/machine/efi/README.md

src/boot/loader.cpp

@@ -82,7 +82,7 @@ load_program(
 
 	try_or_raise(
 		bs->allocate_pages(uefi::allocate_type::any_pages,
-			memory::program_type, num_pages, &pages),
+			uefi::memory_type::loader_data, num_pages, &pages),
 		L"Failed allocating space for program");
 
 	bs->set_mem(pages, total_size, 0);

src/boot/main.cpp

@@ -67,7 +67,7 @@ allocate_args_structure(
 		max_programs * sizeof(args::program); // The program structures
 
 	try_or_raise(
-		bs->allocate_pool(memory::args_type, args_size,
+		bs->allocate_pool(uefi::memory_type::loader_data, args_size,
 			reinterpret_cast<void**>(&args)),
 		L"Could not allocate argument memory");
 
@@ -119,9 +119,8 @@ uefi_preboot(uefi::handle image, uefi::system_table *st)
 
 	fs::file disk = fs::get_boot_volume(image, bs);
 
-	const uefi::memory_type mod_type = memory::module_type;
 	buffer symbols = loader::load_file(disk, L"symbol table", L"symbol_table.dat",
-				memory::module_type);
+				uefi::memory_type::loader_data);
 	add_module(args, args::mod_type::symbol_table, symbols);
 
 	for (auto &desc : program_list) {

src/boot/memory.cpp

@@ -39,19 +39,10 @@ static const wchar_t *memory_type_names[] = {
 static const wchar_t *
 memory_type_name(uefi::memory_type t)
 {
-	if (t < uefi::memory_type::max_memory_type) {
+	if (t < uefi::memory_type::max_memory_type)
 		return memory_type_names[static_cast<uint32_t>(t)];
-	}
 
-	switch(t) {
-		/*
-		case args_type:		return L"jsix kernel args";
-		case module_type:	return L"jsix bootloader module";
-		case program_type:	return L"jsix kernel or program code";
-		case table_type:	return L"jsix page tables";
-		*/
-		default: return L"Bad Type Value";
-	}
+	return L"Bad Type Value";
 }
 
 void
@@ -141,7 +132,7 @@ build_kernel_mem_map(kernel::args::header *args, uefi::boot_services *bs)
 	try_or_raise(
 		bs->allocate_pages(
 			uefi::allocate_type::any_pages,
-			module_type,
+			uefi::memory_type::loader_data,
 			bytes_to_pages(map_size),
 			reinterpret_cast<void**>(&kernel_map)),
 		L"Error allocating kernel memory map module space");
@@ -166,13 +157,16 @@ build_kernel_mem_map(kernel::args::header *args, uefi::boot_services *bs)
 				continue;
 
 			case uefi::memory_type::loader_code:
-			case uefi::memory_type::loader_data:
 			case uefi::memory_type::boot_services_code:
 			case uefi::memory_type::boot_services_data:
 			case uefi::memory_type::conventional_memory:
 				type = mem_type::free;
 				break;
 
+			case uefi::memory_type::loader_data:
+				type = mem_type::pending;
+				break;
+
 			case uefi::memory_type::runtime_services_code:
 			case uefi::memory_type::runtime_services_data:
 				type = mem_type::uefi_runtime;
@@ -191,24 +185,6 @@ build_kernel_mem_map(kernel::args::header *args, uefi::boot_services *bs)
 				type = mem_type::persistent;
 				break;
 
-				/*
-			case args_type:
-				type = mem_type::args;
-				break;
-
-			case module_type:
-				type = mem_type::module;
-				break;
-
-			case program_type:
-				type = mem_type::program;
-				break;
-
-			case table_type:
-				type = mem_type::table;
-				break;
-			*/
-
 			default:
 				error::raise(
 					uefi::status::invalid_parameter,

src/boot/memory.h

@@ -18,28 +18,6 @@ inline constexpr size_t bytes_to_pages(size_t bytes) {
 	return ((bytes - 1) / page_size) + 1;
 }
 
-/// \defgroup memory_types
-/// Custom UEFI memory type values used for data being passed to the kernel
-/// @{
-
-/// Memory containing the kernel args structure
-constexpr uefi::memory_type args_type =
-	static_cast<uefi::memory_type>(0x80000000);
-
-/// Memory containing any loaded modules to be passed to the kernel
-constexpr uefi::memory_type module_type =
-	static_cast<uefi::memory_type>(0x80000001);
-
-/// Memory containing loaded kernel or program code and data sections
-constexpr uefi::memory_type program_type =
-	static_cast<uefi::memory_type>(0x80000002);
-
-/// Memory containing page tables set up by the loader
-constexpr uefi::memory_type table_type =
-	static_cast<uefi::memory_type>(0x80000003);
-
-/// @}
-
 /// \defgroup pointer_fixup
 /// Memory virtualization pointer fixup functions. Handles changing affected pointers
 /// when calling UEFI's `set_virtual_address_map` function to change the location of

src/boot/paging.cpp

@@ -202,7 +202,7 @@ allocate_tables(kernel::args::header *args, uefi::boot_services *bs)
 	try_or_raise(
 		bs->allocate_pages(
 			uefi::allocate_type::any_pages,
-			memory::table_type,
+			uefi::memory_type::loader_data,
 			tables_needed,
 			&addr),
 		L"Error allocating page table pages.");

src/include/kernel_args.h

@@ -44,10 +44,7 @@ struct program {
 
 enum class mem_type : uint32_t {
 	free,
-	args,
-	program,
-	module,
-	table,
+	pending,
 	acpi,
 	uefi_runtime,
 	mmio,

src/kernel/memory_bootstrap.cpp

@@ -110,6 +110,7 @@ memory_initialize_pre_ctors(args::header *kargs)
 	const size_t count = kargs->map_count;
 	for (unsigned i = 0; i < count; ++i) {
 		// TODO: use entry attributes
+		// TODO: copy anything we need from "pending" memory and free it
 		args::mem_entry &e = entries[i];
 		if (e.type == args::mem_type::free)
 			g_frame_allocator.free(e.start, e.pages);