src/mainboard/motorola/sandpoint/nvram/nvram.c

   1 /* $Id$ */
   2 /* Copyright 2000  AG Electronics Ltd. */
   3 /* This code is distributed without warranty under the GPL v2 (see COPYING) */
   4
   5 #include <types.h>
   6 #include <printk.h>
   7 #include <stdlib.h>
   8 #include "../nvram.h"
   9
  10 /* NVRAM layout
  11  *
  12  * Environment variable record runs:
  13  * [length]NAME=value[length]NAME=value[0]\0
  14  * A deleted variable is:
  15  * [length]\0AME=value
  16  *
  17  * When memory is full, we compact.
  18  *
  19  */
  20 static nvram_device *nvram_dev = 0;
  21 static unsigned char *nvram_buffer = 0;
  22 static unsigned nvram_size = 0;
  23 static u8 nvram_csum = 0;
  24 #define NVRAM_INVALID (! nvram_dev)
  25
  26 static void update_device(unsigned i, unsigned char data)
  27 {
  28     if (i < nvram_size)
  29     {
  30         nvram_csum -= nvram_buffer[i];
  31         nvram_buffer[i] = data;
  32         nvram_dev->write_byte(nvram_dev, i, data);
  33         nvram_csum += data;
  34     }
  35     else
  36         printk_info("Offset %d out of range in nvram\n", i);
  37 }
  38
  39 static void update_csum(void)
  40 {
  41     nvram_dev->write_byte(nvram_dev, nvram_size, nvram_csum);
  42     if (nvram_dev->commit)
  43         nvram_dev->commit(nvram_dev);
  44 }
  45
  46 static void update_string_device(unsigned i, const unsigned char *data,
  47                             unsigned len)
  48 {
  49     if (i + len < nvram_size)
  50     {
  51         unsigned j;
  52         for(j = 0; j < len; j++)
  53         {
  54             nvram_csum -= nvram_buffer[i];
  55             nvram_buffer[i] = *data;
  56             nvram_dev->write_byte(nvram_dev, i, *data);
  57             nvram_csum += *data;
  58             data++;
  59             i++;
  60         }
  61     }
  62     else
  63         printk_info("Offset %d out of range in nvram\n", i + len);
  64 }
  65
  66 int nvram_init (struct nvram_device *dev)
  67 {
  68     nvram_dev = dev;
  69
  70     if (! nvram_size)
  71         nvram_size = dev->size(dev) - 1;
  72     printk_info("NVRAM size is %d\n", nvram_size);
  73     if (!nvram_buffer)
  74     {
  75         unsigned i;
  76
  77         nvram_buffer = malloc (nvram_size);
  78         if (!nvram_buffer)
  79             return -1;
  80
  81         nvram_csum = 0;
  82         dev->read_block(dev, 0, nvram_buffer, nvram_size+1);
  83         for(i = 0; i < nvram_size; i++)
  84             nvram_csum += nvram_buffer[i];
  85
  86         if (nvram_csum != nvram_buffer[nvram_size])
  87         {
  88             printk_info("NVRAM checksum invalid - erasing\n");
  89             //update_device(0, 0);
  90             //update_csum();
  91         }
  92     }
  93     printk_info("Initialised nvram\n");
  94     return 0;
  95 }
  96
  97 void nvram_clear(void)
  98 {
  99     printk_info("Erasing NVRAM\n");
 100     update_device(0, 0);
 101     update_csum();
 102 }
 103