1 /*
2 * Common Hardware Reference Platform NVRAM functions.
3 *
4 * This code is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published
6 * by the Free Software Foundation; either version 2 of the License,
7 * or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU 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, see <http://www.gnu.org/licenses/>.
16 */
17
18 #ifndef CHRP_NVRAM_H
19 #define CHRP_NVRAM_H
20
21 #include "qemu/bswap.h"
22
23 /* OpenBIOS NVRAM partition */
24 typedef struct {
25 uint8_t signature;
26 uint8_t checksum;
27 uint16_t len; /* Big endian, length divided by 16 */
28 char name[12];
29 } ChrpNvramPartHdr;
30
31 #define CHRP_NVPART_SYSTEM 0x70
32 #define CHRP_NVPART_FREE 0x7f
33
34 static inline void
chrp_nvram_finish_partition(ChrpNvramPartHdr * header,uint32_t size)35 chrp_nvram_finish_partition(ChrpNvramPartHdr *header, uint32_t size)
36 {
37 unsigned int i, sum;
38 uint8_t *tmpptr;
39
40 /* Length divided by 16 */
41 header->len = cpu_to_be16(size >> 4);
42
43 /* Checksum */
44 tmpptr = (uint8_t *)header;
45 sum = *tmpptr;
46 for (i = 0; i < 14; i++) {
47 sum += tmpptr[2 + i];
48 sum = (sum + ((sum & 0xff00) >> 8)) & 0xff;
49 }
50 header->checksum = sum & 0xff;
51 }
52
53 /* chrp_nvram_create_system_partition() failure is fatal */
54 int chrp_nvram_create_system_partition(uint8_t *data, int min_len, int max_len);
55 int chrp_nvram_create_free_partition(uint8_t *data, int len);
56
57 #endif
58