Kernel: Don't ignore modules passed with multiboot2

kernel/arch/i686/boot.S

@@ -36,6 +36,12 @@ multiboot2_start:
 	.long 12
 	.long V2P(_start)
 
+	# page align modules
+	.align 8
+	.short 6
+	.short 0
+	.long 8
+
 	.align 8
 	.short 0
 	.short 0

kernel/arch/x86_64/boot.S

@@ -36,6 +36,12 @@ multiboot2_start:
 	.long 12
 	.long V2P(_start)
 
+	# page align modules
+	.align 8
+	.short 6
+	.short 0
+	.long 8
+
 	.align 8
 	.short 0
 	.short 0

kernel/include/kernel/BootInfo.h

@@ -41,6 +41,12 @@ namespace Kernel
 		Type     type;
 	};
 
+	struct BootModule
+	{
+		paddr_t start;
+		size_t size;
+	};
+
 	struct BootInfo
 	{
 		BAN::String     command_line;
@@ -48,6 +54,7 @@ namespace Kernel
 		RSDP            rsdp         {};
 		paddr_t         kernel_paddr {};
 
+		BAN::Vector<BootModule> modules;
 		BAN::Vector<MemoryMapEntry>	memory_map_entries;
 	};
 

kernel/include/kernel/multiboot2.h

@@ -6,6 +6,7 @@
 
 #define MULTIBOOT2_TAG_END			0
 #define MULTIBOOT2_TAG_CMDLINE		1
+#define MULTIBOOT2_TAG_MODULES		3
 #define MULTIBOOT2_TAG_MMAP			6
 #define MULTIBOOT2_TAG_FRAMEBUFFER	8
 #define MULTIBOOT2_TAG_OLD_RSDP		14
@@ -33,6 +34,13 @@ struct multiboot2_cmdline_tag_t : public multiboot2_tag_t
 	char cmdline[];
 } __attribute__((packed));
 
+struct multiboot2_modules_tag_t : public multiboot2_tag_t
+{
+	uint32_t mod_start;
+	uint32_t mod_end;
+	uint8_t string[];
+} __attribute__((packed));
+
 struct multiboot2_mmap_entry_t
 {
 	uint64_t base_addr;

kernel/kernel/BootInfo.cpp

@@ -26,12 +26,21 @@ namespace Kernel
 
 		for (const auto* tag = multiboot2_info.tags; tag->type != MULTIBOOT2_TAG_END; tag = tag->next())
 		{
-			if (tag->type == MULTIBOOT2_TAG_CMDLINE)
+			switch (tag->type)
+			{
+				case MULTIBOOT2_TAG_CMDLINE:
 				{
 					const auto& command_line_tag = *static_cast<const multiboot2_cmdline_tag_t*>(tag);
 					MUST(g_boot_info.command_line.append(command_line_tag.cmdline));
+					break;
 				}
-			else if (tag->type == MULTIBOOT2_TAG_FRAMEBUFFER)
+				case MULTIBOOT2_TAG_MODULES:
+				{
+					const auto& modules_tag = *static_cast<const multiboot2_modules_tag_t*>(tag);
+					MUST(g_boot_info.modules.emplace_back(modules_tag.mod_start, modules_tag.mod_end - modules_tag.mod_start));
+					break;
+				}
+				case MULTIBOOT2_TAG_FRAMEBUFFER:
 				{
 					const auto& framebuffer_tag = *static_cast<const multiboot2_framebuffer_tag_t*>(tag);
 					g_boot_info.framebuffer.address	= framebuffer_tag.framebuffer_addr;
@@ -45,8 +54,9 @@ namespace Kernel
 						g_boot_info.framebuffer.type = FramebufferInfo::Type::Text;
 					else
 						g_boot_info.framebuffer.type = FramebufferInfo::Type::Unknown;
+					break;
 				}
-			else if (tag->type == MULTIBOOT2_TAG_MMAP)
+				case MULTIBOOT2_TAG_MMAP:
 				{
 					const auto& mmap_tag = *static_cast<const multiboot2_mmap_tag_t*>(tag);
 
@@ -66,19 +76,23 @@ namespace Kernel
 						g_boot_info.memory_map_entries[i].length  = mmap_entry.length;
 						g_boot_info.memory_map_entries[i].type    = bios_number_to_memory_type(mmap_entry.type);
 					}
+					break;
 				}
-			else if (tag->type == MULTIBOOT2_TAG_OLD_RSDP)
+				case MULTIBOOT2_TAG_OLD_RSDP:
 				{
 					if (g_boot_info.rsdp.length == 0)
 					{
 						memcpy(&g_boot_info.rsdp, static_cast<const multiboot2_rsdp_tag_t*>(tag)->data, 20);
 						g_boot_info.rsdp.length = 20;
 					}
+					break;
 				}
-			else if (tag->type == MULTIBOOT2_TAG_NEW_RSDP)
+				case MULTIBOOT2_TAG_NEW_RSDP:
 				{
 					const auto& rsdp = *reinterpret_cast<const RSDP*>(static_cast<const multiboot2_rsdp_tag_t*>(tag)->data);
 					memcpy(&g_boot_info.rsdp, &rsdp, BAN::Math::min<uint32_t>(rsdp.length, sizeof(g_boot_info.rsdp)));
+					break;
+				}
 			}
 		}
 

kernel/kernel/Memory/Heap.cpp

@@ -58,9 +58,13 @@ namespace Kernel
 			if (entry.type != MemoryMapEntry::Type::Available)
 				continue;
 
+			// FIXME: only reserve kernel area and modules, not everything from 0 -> kernel end
 			paddr_t start = entry.address;
 			if (start < (vaddr_t)g_kernel_end - KERNEL_OFFSET + g_boot_info.kernel_paddr)
 				start = (vaddr_t)g_kernel_end - KERNEL_OFFSET + g_boot_info.kernel_paddr;
+			for (const auto& module : g_boot_info.modules)
+				if (start < module.start + module.size)
+					start = module.start + module.size;
 			if (auto rem = start % PAGE_SIZE)
 				start += PAGE_SIZE - rem;
 

kernel/kernel/kernel.cpp

@@ -258,6 +258,9 @@ static void init2(void*)
 	VirtualFileSystem::initialize(cmdline.root);
 	dprintln("VFS initialized");
 
+	// FIXME: release memory used by modules. If modules are used
+	//        they are already loaded in here
+
 	TTY::initialize_devices();
 
 	auto console_path = MUST(BAN::String::formatted("/dev/{}", cmdline.console));