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/hw.h"
  25 #include "hw/nvram/chrp_nvram.h"
  26 #include "sysemu/sysemu.h"
  27
  28 static int chrp_nvram_set_var(uint8_t *nvram, int addr, const char *str)
  29 {
  30     int len;
  31
  32     len = strlen(str) + 1;
  33     memcpy(&nvram[addr], str, len);
  34
  35     return addr + len;
  36 }
  37
  38 /**
  39  * Create a "system partition", used for the Open Firmware
  40  * environment variables.
  41  */
  42 int chrp_nvram_create_system_partition(uint8_t *data, int min_len)
  43 {
  44     ChrpNvramPartHdr *part_header;
  45     unsigned int i;
  46     int end;
  47
  48     part_header = (ChrpNvramPartHdr *)data;
  49     part_header->signature = CHRP_NVPART_SYSTEM;
  50     pstrcpy(part_header->name, sizeof(part_header->name), "system");
  51
  52     end = sizeof(ChrpNvramPartHdr);
  53     for (i = 0; i < nb_prom_envs; i++) {
  54         end = chrp_nvram_set_var(data, end, prom_envs[i]);
  55     }
  56
  57     /* End marker */
  58     data[end++] = '\0';
  59
  60     end = (end + 15) & ~15;
  61     /* XXX: OpenBIOS is not able to grow up a partition. Leave some space for
  62        new variables. */
  63     if (end < min_len) {
  64         end = min_len;
  65     }
  66     chrp_nvram_finish_partition(part_header, end);
  67
  68     return end;
  69 }
  70
  71 /**
  72  * Create a "free space" partition
  73  */
  74 int chrp_nvram_create_free_partition(uint8_t *data, int len)
  75 {
  76     ChrpNvramPartHdr *part_header;
  77
  78     part_header = (ChrpNvramPartHdr *)data;
  79     part_header->signature = CHRP_NVPART_FREE;
  80     pstrcpy(part_header->name, sizeof(part_header->name), "free");
  81
  82     chrp_nvram_finish_partition(part_header, len);
  83
  84     return len;
  85 }