hw/nvram/chrp_nvram.c

   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 "hw/nvram/chrp_nvram.h"
  25 #include "sysemu/sysemu.h"
  26
  27 static int chrp_nvram_set_var(uint8_t *nvram, int addr, const char *str)
  28 {
  29     int len;
  30
  31     len = strlen(str) + 1;
  32     memcpy(&nvram[addr], str, len);
  33
  34     return addr + len;
  35 }
  36
  37 /**
  38  * Create a "system partition", used for the Open Firmware
  39  * environment variables.
  40  */
  41 int chrp_nvram_create_system_partition(uint8_t *data, int min_len)
  42 {
  43     ChrpNvramPartHdr *part_header;
  44     unsigned int i;
  45     int end;
  46
  47     part_header = (ChrpNvramPartHdr *)data;
  48     part_header->signature = CHRP_NVPART_SYSTEM;
  49     pstrcpy(part_header->name, sizeof(part_header->name), "system");
  50
  51     end = sizeof(ChrpNvramPartHdr);
  52     for (i = 0; i < nb_prom_envs; i++) {
  53         end = chrp_nvram_set_var(data, end, prom_envs[i]);
  54     }
  55
  56     /* End marker */
  57     data[end++] = '\0';
  58
  59     end = (end + 15) & ~15;
  60     /* XXX: OpenBIOS is not able to grow up a partition. Leave some space for
  61        new variables. */
  62     if (end < min_len) {
  63         end = min_len;
  64     }
  65     chrp_nvram_finish_partition(part_header, end);
  66
  67     return end;
  68 }
  69
  70 /**
  71  * Create a "free space" partition
  72  */
  73 int chrp_nvram_create_free_partition(uint8_t *data, int len)
  74 {
  75     ChrpNvramPartHdr *part_header;
  76
  77     part_header = (ChrpNvramPartHdr *)data;
  78     part_header->signature = CHRP_NVPART_FREE;
  79     pstrcpy(part_header->name, sizeof(part_header->name), "free");
  80
  81     chrp_nvram_finish_partition(part_header, len);
  82
  83     return len;
  84 }