7ea8f3b7d226bbc9014424d449f22c7b353e2898
[reactos.git] / boot / freeldr / freeldr / arch / i386 / linux.S
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
23 EXTERN i386CallRealMode:PROC
24
25 .code32
26
27 /*
28 * VOID BootOldLinuxKernel(ULONG KernelSize);
29 */
30 PUBLIC _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
46 PUBLIC _BootNewLinuxKernel
47 _BootNewLinuxKernel:
48
49 mov bx, FNID_BootLinuxKernel
50 call i386CallRealMode
51
52 /* We should never get here */
53 int 3
54
55 END