cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

chrp_nvram.c (2764B)

      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}