qemu/hw/nvram/chrp_nvram.c
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   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
  28static 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 */
  42int 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 */
  74int 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}
  86