; xandu - a unix like kernel
; written by Aaron "Dark_Aaron" Blakely, Michael "OoO" Raines, and Daniel "Yay" Heinrichs
;
; glue assembly - for

global loader               ; make entry point visable to linker
extern kernel_start         ; defined in kernel.c

; setup Multiboot headers for GRUB
MODULEALGIN     equ     1<<0                        ; align loaded modules on page boundaries
MEMINFO         equ     1<<1                        ; provide memory map
FLAGS           equ     MODULEALIGN | MEMINFO       ; this is the Multiboot 'flag' field
MAGIC           equ     0x1BADB002                  ; 'magic number' lets bootloader find the header
CHECKSUM        equ     -(MAGIC + FLAGS)            ; checksum

section .text
align 4

MultiBootHeader:
    dd  MAGIC
    dd  FLAGS
    dd  CHECKSUM

; reserver inital kernel stack space
STACKSIZE       equ     0x4000          ; 16k

loader:
    mov     esp, stack+STACKSIZE        ; setup the stack
    push    eax                         ; pass Multiboot magic number
    push    ebx                         ; pass Multiboot info structure

    call    kernel_start                ; call the kernel_start function
    cli

hang:
    hlt                                 ; hault the machine, if the kernel returns
    jmp     hang

section .bss
align 4
stack:
    resb STACKSTIZE                     ; reserve the kernel stack memory