src/mainboard/motorola/sandpointx3_altimus_mpc7410/nvram/nvram.c

   1 /* Copyright 2000  AG Electronics Ltd. */
   2 /* This code is distributed without warranty under the GPL v2 (see COPYING) */
   3
   4 #include <console/console.h>
   5 #include <stdlib.h>
   6 #include "../nvram.h"
   7
   8 /* NVRAM layout
   9  *
  10  * Environment variable record runs:
  11  * [length]NAME=value[length]NAME=value[0]\0
  12  * A deleted variable is:
  13  * [length]\0AME=value
  14  *
  15  * When memory is full, we compact.
  16  *
  17  */
  18 static nvram_device *nvram_dev = 0;
  19 static unsigned char *nvram_buffer = 0;
  20 static unsigned nvram_size = 0;
  21 static uint8_t nvram_csum = 0;
  22 #define NVRAM_INVALID (! nvram_dev)
  23
  24 static void update_device(unsigned i, unsigned char data)
  25 {
  26     if (i < nvram_size)
  27     {
  28         nvram_csum -= nvram_buffer[i];
  29         nvram_buffer[i] = data;
  30         nvram_dev->write_byte(nvram_dev, i, data);
  31         nvram_csum += data;
  32     }
  33     else
  34         printk_info("Offset %d out of range in nvram\n", i);
  35 }
  36
  37 static void update_csum(void)
  38 {
  39     nvram_dev->write_byte(nvram_dev, nvram_size, nvram_csum);
  40     if (nvram_dev->commit)
  41         nvram_dev->commit(nvram_dev);
  42 }
  43
  44 static void update_string_device(unsigned i, const unsigned char *data,
  45                             unsigned len)
  46 {
  47     if (i + len < nvram_size)
  48     {
  49         unsigned j;
  50         for(j = 0; j < len; j++)
  51         {
  52             nvram_csum -= nvram_buffer[i];
  53             nvram_buffer[i] = *data;
  54             nvram_dev->write_byte(nvram_dev, i, *data);
  55             nvram_csum += *data;
  56             data++;
  57             i++;
  58         }
  59     }
  60     else
  61         printk_info("Offset %d out of range in nvram\n", i + len);
  62 }
  63
  64 int nvram_init (struct nvram_device *dev)
  65 {
  66     nvram_dev = dev;
  67
  68     if (! nvram_size)
  69         nvram_size = dev->size(dev) - 1;
  70     printk_info("NVRAM size is %d\n", nvram_size);
  71     if (!nvram_buffer)
  72     {
  73         unsigned i;
  74
  75         nvram_buffer = malloc (nvram_size);
  76         if (!nvram_buffer)
  77             return -1;
  78
  79         nvram_csum = 0;
  80         dev->read_block(dev, 0, nvram_buffer, nvram_size+1);
  81         for(i = 0; i < nvram_size; i++)
  82             nvram_csum += nvram_buffer[i];
  83
  84         if (nvram_csum != nvram_buffer[nvram_size])
  85         {
  86             printk_info("NVRAM checksum invalid - erasing\n");
  87             //update_device(0, 0);
  88             //update_csum();
  89         }
  90     }
  91     printk_info("Initialised nvram\n");
  92     return 0;
  93 }
  94
  95 void nvram_clear(void)
  96 {
  97     printk_info("Erasing NVRAM\n");
  98     update_device(0, 0);
  99     update_csum();
 100 }
 101