drivers/bootcount/bootcount_ext.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2017 General Electric Company. All rights reserved.
   4  */
   5
   6 #include <bootcount.h>
   7 #include <fs.h>
   8 #include <mapmem.h>
   9
  10 #define BC_MAGIC        0xbd
  11 #define BC_VERSION      1
  12
  13 typedef struct {
  14         u8 magic;
  15         u8 version;
  16         u8 bootcount;
  17         u8 upgrade_available;
  18 } bootcount_ext_t;
  19
  20 static u8 upgrade_available = 1;
  21
  22 void bootcount_store(ulong a)
  23 {
  24         bootcount_ext_t *buf;
  25         loff_t len;
  26         int ret;
  27
  28         if (fs_set_blk_dev(CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE,
  29                            CONFIG_SYS_BOOTCOUNT_EXT_DEVPART, FS_TYPE_EXT)) {
  30                 puts("Error selecting device\n");
  31                 return;
  32         }
  33
  34         /* Only update bootcount during upgrade process */
  35         if (!upgrade_available)
  36                 return;
  37
  38         buf = map_sysmem(CONFIG_SYS_BOOTCOUNT_ADDR, sizeof(bootcount_ext_t));
  39         buf->magic = BC_MAGIC;
  40         buf->version = BC_VERSION;
  41         buf->bootcount = (a & 0xff);
  42         buf->upgrade_available = upgrade_available;
  43         unmap_sysmem(buf);
  44
  45         ret = fs_write(CONFIG_SYS_BOOTCOUNT_EXT_NAME,
  46                        CONFIG_SYS_BOOTCOUNT_ADDR, 0, sizeof(bootcount_ext_t),
  47                        &len);
  48         if (ret != 0)
  49                 puts("Error storing bootcount\n");
  50 }
  51
  52 ulong bootcount_load(void)
  53 {
  54         bootcount_ext_t *buf;
  55         loff_t len_read;
  56         int ret;
  57
  58         if (fs_set_blk_dev(CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE,
  59                            CONFIG_SYS_BOOTCOUNT_EXT_DEVPART, FS_TYPE_EXT)) {
  60                 puts("Error selecting device\n");
  61                 return 0;
  62         }
  63
  64         ret = fs_read(CONFIG_SYS_BOOTCOUNT_EXT_NAME, CONFIG_SYS_BOOTCOUNT_ADDR,
  65                       0, sizeof(bootcount_ext_t), &len_read);
  66         if (ret != 0 || len_read != sizeof(bootcount_ext_t)) {
  67                 puts("Error loading bootcount\n");
  68                 return 0;
  69         }
  70
  71         buf = map_sysmem(CONFIG_SYS_BOOTCOUNT_ADDR, sizeof(bootcount_ext_t));
  72         if (buf->magic == BC_MAGIC && buf->version == BC_VERSION) {
  73                 upgrade_available = buf->upgrade_available;
  74                 if (upgrade_available)
  75                         ret = buf->bootcount;
  76         } else {
  77                 puts("Incorrect bootcount file\n");
  78         }
  79
  80         unmap_sysmem(buf);
  81
  82         return ret;
  83 }