1 #include <stdio.h>

     2 

     3 

     4 /* size of NVRAM in bytes */

     5 #define NVRAM_MAX_SIZE 262144

     6 

     7 /* size of block in byte */

     8 #define NVRAM_BLOCK_SIZE 256

     9 

    10 #define NVRAM_FILE_NAME "__nvram__"

    11 

    12 FILE *nvram_file = NULL;

    13 

    14 

    15 void iat_flash_read_regs();

    16 void iat_flash_write_regs();

    17 void iat_flash_write_page(unsigned int);

    18 void iat_flash_read_page(unsigned int);

    19 

    20 

    21 short data_len; /* 0 to NVRAM_BLOCK_SIZE bytes */

    22 short data_num_pages;

    23 unsigned int *data_page = NULL;

    24 unsigned int data_addr;

    25 

    26 unsigned int *regs_page = NULL;

    27 

    28 int iat_init()

    29 {

    30 	int i;

    31 

    32 	nvram_file = fopen(NVRAM_FILE_NAME, "wr");

    33 	if (nvram_file  == NULL)

    34 		return -1;

    35 

    36 	int n = NVRAM_BLOCK_SIZE / sizeof(unsigned int);

    37 

    38 	/* some actions to initialise the flash */

    39 	data_len = 0;

    40 	data_num_pages = 0;

    41 

    42 	data_page = (unsigned int *)malloc(sizeof(unsigned int) * n);

    43 	memset(data_page, 0, sizeof(unsigned int)*n);

    44 

    45 	if (data_page == NULL)

    46 		return -1;

    47 

    48 	regs_page = (unsigned int *)malloc(sizeof(unsigned int) * n);

    49 	memset(regs_page, 0, sizeof(unsigned int)*n);

    50 	if (regs_page == NULL)

    51 		return -2;

    52 

    53 	iat_flash_read_regs();

    54 

    55 	/* start the data at the location specified in the registers */ 

    56 	if (0) /* for now it is 0, but put here a test to know whether

    57                   or not the NVRAM has been written before */

    58 		data_addr = regs_page[1];

    59 	else

    60 		data_addr = NVRAM_BLOCK_SIZE; /* let start at block 1 */

    61 

    62 	/* create a file the size of the simulated NVRAM */

    63 	for(i=0; i<NVRAM_MAX_SIZE/NVRAM_BLOCK_SIZE + 1; i++)

    64 		fwrite(data_page, sizeof(unsigned int), n, nvram_file);

    65 

    66 	return 0;

    67 }

    68 

    69 

    70 void iat_end()

    71 {

    72 	iat_flash_write_page(data_addr);

    73 

    74 	iat_flash_write_regs();

    75 

    76 	fclose(nvram_file);

    77 }

    78 

    79  

    80 void iat_flash_read_regs()

    81 {

    82 	fseek(nvram_file, 0, SEEK_SET);

    83 	fread(regs_page, sizeof(unsigned int), NVRAM_BLOCK_SIZE, nvram_file);

    84 }

    85 

    86 

    87 void iat_flash_write_regs()

    88 {

    89 	fseek(nvram_file, 0, SEEK_SET);

    90 	fwrite(regs_page, sizeof(unsigned int), NVRAM_BLOCK_SIZE, nvram_file);

    91 }

    92 

    93 

    94 void iat_flash_read_page(unsigned int addr)

    95 {

    96 	fseek(nvram_file, addr*sizeof(unsigned int), SEEK_SET);

    97 	fread(data_page, sizeof(unsigned int), NVRAM_BLOCK_SIZE, nvram_file);

    98 }

    99 

   100 

   101 void iat_flash_write_page(unsigned int addr)

   102 {

   103 	fseek(nvram_file, addr*sizeof(unsigned int), SEEK_SET);

   104 	fwrite(data_page, sizeof(unsigned int), NVRAM_BLOCK_SIZE, nvram_file);

   105 }

   106 

   107 

   108 /*------------------------------------------------------*/

   109 int main()

   110 {

   111 	iat_init();

   112 	iat_end();

   113 }

   114 /*------------------------------------------------------*/