First step towards x86_64

kernel.settings

@@ -1,10 +1,15 @@
-arch = x86
+arch = x86_64
 #MODE = debug
 MODE = release # enables optimization
 
 export PATH := $(HOME)/opt/bin:$(PATH)
-#PREFIX =
-PREFIX = i686-elf-
+ifeq ($(arch),x86)
+  PREFIX = i686-elf-
+else
+  ifeq ($(arch),x86_64)
+    PREFIX = x86_64-elf-
+  endif
+endif
 
 ifeq ($(MODE),debug)
   	CFLAGS += -g3 -DDEBUG

kernel/hal/x86_64/boot/boot.S

@@ -0,0 +1,127 @@
+.code32
+.section multiboot
+#define MB_MAGIC 0x1BADB002
+#define MB_FLAGS 0x0
+#define MB_CHECKSUM -(MB_MAGIC + MB_FLAGS)
+.align 4
+.int MB_MAGIC
+.int MB_FLAGS
+.int MB_CHECKSUM
+.section .text
+.extern init
+.global _start
+_start:
+  mov $mb_ptr, %edi
+  stosl
+  mov %ebx, %eax
+  stosl //Temponarily store both multiboot header pointer and multiboot
+  mov $kernel_stack, %esp
+  mov $0x80000001, %eax //Check if Long Mode is supported
+  cpuid
+  and $0x20000000, %edx
+  jz x86_64_err
+
+  xor %eax, %eax //Check if PAE is supported
+  inc %eax
+  cpuid
+  and $0x40, %dl
+  jz x86_64_err
+  jmp x86_64_OK
+x86_64_err:
+  cli
+  hlt
+  jmp x86_64_err
+x86_64_OK:
+  //Fill one entry of both the pagemap L4 and the Pagedir PT
+  mov $pmfill, %esi
+  mov $pagemapL4, %edi
+  lodsl
+  stosl
+  lodsl
+  stosl
+  mov $pagedirPT, %edi
+  lodsl
+  stosl
+  lodsl
+  stosl
+  //Activate PAE
+  mov %cr4, %eax
+  or $0x20, %al
+  mov %eax, %cr4
+  //Activate x86_64
+  mov $0xC0000080, %ecx
+  rdmsr
+  or $0x00000100, %eax
+  wrmsr
+  //Load Page Table
+  mov $pagemapL4, %eax
+  mov %eax, %cr3
+  //Activate Paging
+  mov %cr0, %eax
+  bswap %eax
+  or $0x80, %al
+  bswap %eax
+  mov %eax, %cr0
+  //Jump to x86_64loader
+  lgdt gdtr
+  jmp $0x18, $start
+
+.code64
+//extern "C" void init(uint32_t eax, multiboot_info * ebx, uint64_t **** pt);
+.global init
+start:
+  xor %rax, %rax
+  mov $mb_ptr, %rsi
+  lodsl
+  mov %rax, %rdi
+  lodsl
+  mov %rax, %rsi
+  mov $pagemapL4, %rdx
+  call init
+stop:
+  cli
+  hlt
+  jmp stop
+.section .data
+gdt:
+//NULL-descriptor
+.quad 0
+//32-bit code
+.word 0xFFFF
+.word 0x0000
+.byte 0x00
+.byte 0x98
+.byte 0xCF
+.byte 0x00
+//data
+.word 0xFFFF
+.word 0x0000
+.byte 0x00
+.byte 0x92
+.byte 0xCF
+.byte 00
+//64-bit code
+.int 0
+.byte 0
+.byte 0x98
+.byte 0x20
+.byte 0
+
+gdtr:
+  .word 4 * 8
+  .int gdt
+pmfill:
+.int pagedirPT + 0x7
+.int 0
+pdptfill:
+.quad 0x87
+.section .bss
+mb_ptr:
+// These 8 Bytes will never be used when the stack comes near it
+.space 4096
+kernel_stack:
+.align 4096
+pagemapL4:
+.space 4096
+pagedirPT:
+.space 4096