# # Copyright (C) 2001-2004 Jakub Jermar # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # # - Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # - Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # - The name of the author may not be used to endorse or promote products # derived from this software without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # .section K_TEXT_START .global kernel_image_start .code16 # # This is where we require any SPARTAN-kernel-compatible boot loader # to pass control in real mode. # # Protected mode tables are statically initialised during compile # time. So we can just load the respective table registers and # switch to protected mode. # kernel_image_start: call memmap_arch_init cli xorw %ax,%ax movw %ax,%ds lgdt gdtr movl %cr0,%eax orl $0x1,%eax movl %eax,%cr0 jmp 0f 0: movw $16,%ax movw %ax,%es movw %ax,%gs movw %ax,%fs movw %ax,%ds # kernel data + stack movw %ax,%ss movl $0x7c00,%esp jmpl $8,$meeting_point meeting_point: .code32 lidt idtr call main_bsp # never returns cli hlt