xref: /reactos/boot/freeldr/freeldr/arch/i386/linux.S (revision 50cf16b3)
1/*
2 *  FreeLoader
3 *  Copyright (C) 1998-2002  Brian Palmer  <brianp@sginet.com>
4 *
5 *  This program is free software; you can redistribute it and/or modify
6 *  it under the terms of the GNU General Public License as published by
7 *  the Free Software Foundation; either version 2 of the License, or
8 *  (at your option) any later version.
9 *
10 *  This program is distributed in the hope that it will be useful,
11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 *  GNU General Public License for more details.
14 *
15 *  You should have received a copy of the GNU General Public License along
16 *  with this program; if not, write to the Free Software Foundation, Inc.,
17 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20#include <asm.inc>
21#include <arch/pc/x86common.h>
22
23EXTERN i386CallRealMode:PROC
24
25.code32
26
27/*
28 *  VOID BootOldLinuxKernel(ULONG KernelSize);
29 */
30PUBLIC _BootOldLinuxKernel
31_BootOldLinuxKernel:
32
33    /* First we have to copy the kernel down from 0x100000 to 0x10000 */
34    /* The reason we can overwrite low memory is because this code */
35    /* executes between 0000:8000 and 0000:FFFF. That leaves space for */
36    /* 32k of code before we start interfering with Linux kernel address space. */
37
38    /* Get KernelSize in ECX and move the kernel down */
39    mov ecx, [esp + 4]
40    mov esi, HEX(100000)
41    mov edi, HEX(10000)
42    rep movsb
43
44    /* Fall through */
45
46PUBLIC _BootNewLinuxKernel
47_BootNewLinuxKernel:
48
49    mov bx, FNID_BootLinuxKernel
50    call i386CallRealMode
51
52    /* We should never get here */
53    int 3
54
55END
56