include/hw/nvram/chrp_nvram.h

   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
  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