Kernel: Kmalloc now has its memory statically allocated

We don't use the memory map given by bootloader since this automatically
maps the memory to a available space.

kernel/arch/i386/MMU.cpp

@@ -47,6 +47,8 @@ MMU::MMU()
 		m_highest_paging_struct[i] = (uint64_t)page_directory | Flags::Present;
 	}
 
+	// FIXME: We should just identity map until g_kernel_end
+
 	// create and identity map first 6 MiB
 	uint64_t* page_directory1 = (uint64_t*)(m_highest_paging_struct[0] & PAGE_MASK);
 	for (uint64_t i = 0; i < 3; i++)

kernel/arch/i386/boot.S

@@ -28,9 +28,7 @@ g_boot_stack_bottom:
 g_boot_stack_top:
 
 # 0 MiB -> 1 MiB: bootloader stuff
-# 1 MiB -> 2 MiB: kernel
+# 1 MiB ->      : kernel
-# 2 MiB -> 3 MiB: kmalloc
-# 3 MiB -> 4 Mib: kmalloc_fixed
 .align 32
 boot_page_directory_pointer_table:
 	.skip 4 * 8

kernel/arch/x86_64/MMU.cpp

@@ -35,7 +35,9 @@ static uint64_t* allocate_page_aligned_page()
 
 MMU::MMU()
 {
-	// Identity map from 4 KiB -> 6 MiB
+	// FIXME: We should just identity map until g_kernel_end
+
+	// Identity map from 0 -> 6 MiB
 	m_highest_paging_struct = allocate_page_aligned_page();
 	
 	uint64_t* pdpt = allocate_page_aligned_page();

kernel/arch/x86_64/boot.S

@@ -41,9 +41,7 @@
 	# we will identity map first 4 MiB
 
 	# 0 MiB -> 1 MiB: bootloader stuff
-	# 1 MiB -> 4 MiB: kernel
+	# 1 MiB ->      : kernel
-	# 4 MiB -> 5 MiB: kmalloc
-	# 5 MiB -> 6 MiB: kmalloc_fixed
 	.align 4096
 	boot_pml4:
 		.skip 512 * 8

kernel/kernel/Memory/kmalloc.cpp

@@ -2,7 +2,6 @@
 #include <kernel/CriticalScope.h>
 #include <kernel/kprint.h>
 #include <kernel/Memory/kmalloc.h>
-#include <kernel/multiboot.h>
 
 #include <kernel/Thread.h>
 
@@ -10,6 +9,8 @@
 
 static constexpr size_t s_kmalloc_min_align = alignof(max_align_t);
 
+static uint8_t s_kmalloc_storage[2 * MB];
+
 struct kmalloc_node
 {
 	void set_align(ptrdiff_t align)			{ m_align = align; }
@@ -60,9 +61,9 @@ static_assert(sizeof(kmalloc_node) == s_kmalloc_min_align);
 
 struct kmalloc_info
 {
-	static constexpr uintptr_t	base = 0x00400000;
+	const uintptr_t	base = (uintptr_t)s_kmalloc_storage;
-	static constexpr size_t		size = 1 * MB;
+	const size_t	size = sizeof(s_kmalloc_storage) / 2;
-	static constexpr uintptr_t	end = base + size;
+	const uintptr_t	end = base + size;
 
 	kmalloc_node* first() { return (kmalloc_node*)base; }
 	kmalloc_node* from_address(void* addr)
@@ -91,11 +92,10 @@ struct kmalloc_fixed_info
 {
 	using node = kmalloc_fixed_node<64>;
 
-	static constexpr uintptr_t	base = s_kmalloc_info.end;
+	const uintptr_t	base = s_kmalloc_info.end;
-	static constexpr size_t		size = 1 * MB;
+	const size_t	size = (uintptr_t)s_kmalloc_storage + sizeof(s_kmalloc_storage) - base;
-	static constexpr uintptr_t	end = base + size;
+	const uintptr_t	end = base + size;
-	static constexpr size_t		node_count = size / sizeof(node);
+	const size_t	node_count = size / sizeof(node);
-	static_assert(node_count < (1 << 16));
 
 	node* free_list_head = NULL;
 	node* used_list_head = NULL;
@@ -108,42 +108,9 @@ struct kmalloc_fixed_info
 };
 static kmalloc_fixed_info s_kmalloc_fixed_info;
 
-extern "C" uintptr_t g_kernel_end;
-
 void kmalloc_initialize()
 {
-	if (!(g_multiboot_info->flags & (1 << 6)))
+	dprintln("kmalloc {8H}->{8H}", (uintptr_t)s_kmalloc_storage, (uintptr_t)s_kmalloc_storage + sizeof(s_kmalloc_storage));
-		Kernel::panic("Kmalloc: Bootloader didn't provide a memory map");
-
-	if ((uintptr_t)&g_kernel_end > s_kmalloc_info.base)
-		Kernel::panic("Kmalloc: Kernel end ({}) is over kmalloc base ({})", &g_kernel_end, (void*)s_kmalloc_info.base);
-
-	// Validate kmalloc memory
-	bool valid = false;
-	for (size_t i = 0; i < g_multiboot_info->mmap_length;)
-	{
-		multiboot_memory_map_t* mmmt = (multiboot_memory_map_t*)(g_multiboot_info->mmap_addr + i);
-
-		if (mmmt->type == 1)
-		{
-			if (mmmt->base_addr <= s_kmalloc_info.base && s_kmalloc_fixed_info.end <= mmmt->base_addr + mmmt->length)
-			{
-				valid = true;
-				break;
-			}
-		}
-
-		i += mmmt->size + sizeof(uint32_t);
-	}
-
-	if (!valid)
-	{
-		size_t kmalloc_total_size = s_kmalloc_info.size + s_kmalloc_fixed_info.size;
-		Kernel::panic("Kmalloc: Could not find {}.{} MB of memory",
-			kmalloc_total_size / MB,
-			kmalloc_total_size % MB
-		);
-	}
 
 	// initialize fixed size allocations
 	{