Pass kernel start/end physical address to Kmain

arch/x86_64/asm/rt0_64.s

@@ -1,4 +1,5 @@
 ; vim: set ft=nasm :
+%include "constants.inc"
 
 section .bss
 align 8
@@ -55,8 +56,14 @@ _rt0_64_entry:
 	; Call the kernel entry point passing a pointer to the multiboot data
 	; copied by the 32-bit entry code
 	extern multiboot_data
+	extern _kernel_start
+	extern _kernel_end
 	extern kernel.Kmain
 	
+	mov rax, _kernel_end - PAGE_OFFSET
+	push rax
+	mov rax, _kernel_start - PAGE_OFFSET
+	push rax
 	mov rax, multiboot_data
 	push rax
 	call kernel.Kmain

arch/x86_64/script/linker.ld.in

@@ -7,6 +7,8 @@ SECTIONS {
 	 * but load it at physical address 1M */
 	. = VMA;
 
+	_kernel_start = .;
+
 	.text BLOCK(4K) : AT(ADDR(.text) - PAGE_OFFSET)
 	{
 		/* The multiboot header must be present in the first 4K of the kernel 
@@ -36,4 +38,6 @@ SECTIONS {
 		*(COMMON)
 		*(.bss)
 	}
+	
+	_kernel_end = ALIGN(4K);
 }