LXR qemu/hw/nvram/chrp

   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 "sysemu/sysemu.h"
  27
  28static 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 */
  48int 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
  83fail:
  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 */
  91int 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}
 103