iPXE
basemem.c
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1 /*
2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA.
18  *
19  * You can also choose to distribute this program under the terms of
20  * the Unmodified Binary Distribution Licence (as given in the file
21  * COPYING.UBDL), provided that you have satisfied its requirements.
22  */
23 
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25 
26 #include <stdint.h>
27 #include <realmode.h>
28 #include <bios.h>
29 #include <basemem.h>
30 #include <ipxe/hidemem.h>
31 
32 /** @file
33  *
34  * Base memory allocation
35  *
36  */
37 
38 /**
39  * Set the BIOS free base memory counter
40  *
41  * @v new_fbms New free base memory counter (in kB)
42  */
43 void set_fbms ( unsigned int new_fbms ) {
44  uint16_t fbms = new_fbms;
45 
46  /* Update the BIOS memory counter */
47  put_real ( fbms, BDA_SEG, BDA_FBMS );
48 
49  /* Update our hidden memory region map */
50  hide_basemem();
51 }
FILE_LICENCE(GPL2_OR_LATER_OR_UBDL)
unsigned short uint16_t
Definition: stdint.h:11
#define BDA_FBMS
Definition: bios.h:9
Base memory allocation.
#define put_real
Definition: libkir.h:150
#define BDA_SEG
Definition: bios.h:6
Hidden memory regions.
void set_fbms(unsigned int new_fbms)
Set the BIOS free base memory counter.
Definition: basemem.c:43
void hide_basemem(void)
Hide used base memory.
Definition: hidemem.c:107