MASM basic kernel

.686 ;32 bit code
.Model flat, StdCall ;32 bit memory model
Option CaseMap:none ;case sensitive

; setting up the Multiboot header - see GRUB docs for details
.Const
    MODULEALIGN Equ 1 Shl 0 ; align loaded modules on page boundaries
    MEMINFO Equ 1 Shl 1 ; provide memory map

Align 4
.Data
    MAGIC DD 1BADB002h
    FLAGS DD (MODULEALIGN or MEMINFO)
    CHECKSUM DD (-(1BADB002h + (MODULEALIGN or MEMINFO)))

Align 4
.Data?
    Stack Byte 4000h Dup(?)
.Code
    Start:
        Mov Ecx, Offset Stack
        Add Ecx, 4000h
        Mov Esp, Ecx; set up the stack
        push eax ; pass Multiboot magic number
        push ebx ; pass Multiboot info structure
        call kmain ; call kernel proper
        cli
        hang:
            hlt ; halt machine should kernel return
            jmp hang
        kmain:
            Pop Eax
            Pop Ebx
            Mov Ah, 65
            Mov Ecx, 0B80000h
            Mov Byte Ptr[Ecx], Ah
            Mov Ah, 07h
            Inc Ecx
            Mov Byte Ptr[Ecx], Ah
    End Start