| 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 "system/system.h" |
| 27 | |
| 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 | */ |
| 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 | */ |
| 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 | } |