1 /*
2 * Common Hardware Reference Platform NVRAM helper functions.
3 *
4 * The CHRP NVRAM layout is used by OpenBIOS and SLOF. See CHRP
5 * specification, chapter 8, or the LoPAPR specification for details
6 * about the NVRAM layout.
7 *
8 * This code is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published
10 * by the Free Software Foundation; either version 2 of the License,
11 * or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "qemu/osdep.h"
23 #include "qemu/cutils.h"
24 #include "qemu/error-report.h"
25 #include "hw/nvram/chrp_nvram.h"
26 #include "sysemu/sysemu.h"
27
chrp_nvram_set_var(uint8_t * nvram,int addr,const char * str,int max_len)28 static int chrp_nvram_set_var(uint8_t *nvram, int addr, const char *str,
29 int max_len)
30 {
31 int len;
32
33 len = strlen(str) + 1;
34
35 if (max_len < len) {
36 return -1;
37 }
38
39 memcpy(&nvram[addr], str, len);
40
41 return addr + len;
42 }
43
44 /**
45 * Create a "system partition", used for the Open Firmware
46 * environment variables.
47 */
chrp_nvram_create_system_partition(uint8_t * data,int min_len,int max_len)48 int chrp_nvram_create_system_partition(uint8_t *data, int min_len, int max_len)
49 {
50 ChrpNvramPartHdr *part_header;
51 unsigned int i;
52 int end;
53
54 if (max_len < sizeof(*part_header)) {
55 goto fail;
56 }
57
58 part_header = (ChrpNvramPartHdr *)data;
59 part_header->signature = CHRP_NVPART_SYSTEM;
60 pstrcpy(part_header->name, sizeof(part_header->name), "system");
61
62 end = sizeof(ChrpNvramPartHdr);
63 for (i = 0; i < nb_prom_envs; i++) {
64 end = chrp_nvram_set_var(data, end, prom_envs[i], max_len - end);
65 if (end == -1) {
66 goto fail;
67 }
68 }
69
70 /* End marker */
71 data[end++] = '\0';
72
73 end = (end + 15) & ~15;
74 /* XXX: OpenBIOS is not able to grow up a partition. Leave some space for
75 new variables. */
76 if (end < min_len) {
77 end = min_len;
78 }
79 chrp_nvram_finish_partition(part_header, end);
80
81 return end;
82
83 fail:
84 error_report("NVRAM is too small. Try to pass less data to -prom-env");
85 exit(EXIT_FAILURE);
86 }
87
88 /**
89 * Create a "free space" partition
90 */
chrp_nvram_create_free_partition(uint8_t * data,int len)91 int chrp_nvram_create_free_partition(uint8_t *data, int len)
92 {
93 ChrpNvramPartHdr *part_header;
94
95 part_header = (ChrpNvramPartHdr *)data;
96 part_header->signature = CHRP_NVPART_FREE;
97 pstrcpy(part_header->name, sizeof(part_header->name), "free");
98
99 chrp_nvram_finish_partition(part_header, len);
100
101 return len;
102 }
103