/*
 * Simple tool to dump the AP_Param contents from an EEPROM dump
 * Andrew Tridgell February 2012
 */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

uint8_t	eeprom[0x1000];

#pragma pack(1)

struct EEPROM_header {
  uint8_t     magic[2];
  uint8_t     revision;
  uint8_t     spare;
};

static const uint16_t   k_EEPROM_magic0     = 0x50;
static const uint16_t   k_EEPROM_magic1     = 0x41;
static const uint16_t   k_EEPROM_revision   = 5;

enum ap_var_type {
    AP_PARAM_NONE    = 0,
    AP_PARAM_INT8,
    AP_PARAM_INT16,
    AP_PARAM_INT32,
    AP_PARAM_FLOAT,
    AP_PARAM_VECTOR3F,
    AP_PARAM_VECTOR6F,
    AP_PARAM_MATRIX3F,
    AP_PARAM_GROUP
};

static const char *type_names[8] = {
	"NONE", "INT8", "INT16", "INT32", "FLOAT", "VECTOR3F", "MATRIX6F", "GROUP"
};

struct Param_header {
        uint8_t    key;
        uint8_t    group_element;
        uint8_t    type;
};


static const uint8_t  _sentinal_key   = 0xFF;
static const uint8_t  _sentinal_type  = 0xFF;
static const uint8_t  _sentinal_group = 0xFF;

static uint8_t type_size(enum ap_var_type type)
{
    switch (type) {
    case AP_PARAM_NONE:
    case AP_PARAM_GROUP:
        return 0;
    case AP_PARAM_INT8:
        return 1;
    case AP_PARAM_INT16:
        return 2;
    case AP_PARAM_INT32:
        return 4;
    case AP_PARAM_FLOAT:
        return 4;
    case AP_PARAM_VECTOR3F:
        return 3*4;
    case AP_PARAM_VECTOR6F:
        return 6*4;
    case AP_PARAM_MATRIX3F:
        return 3*3*4;
    }
    printf("unknown type %u\n", type);
    return 0;
}

static void
fail(const char *why)
{
  fprintf(stderr, "ERROR: %s\n", why);
  exit(1);
}

int
main(int argc, char *argv[])
{
	FILE			*fp;
	struct EEPROM_header	*header;
	struct Param_header	*var;
	unsigned		index;
	unsigned		i;

	if (argc != 2) {
		fail("missing EEPROM file name");
	}
	if (NULL == (fp = fopen(argv[1], "rb"))) {
		fail("can't open EEPROM file");
	}
	if (1 != fread(eeprom, sizeof(eeprom), 1, fp)) {
		fail("can't read EEPROM file");
	}
	fclose(fp);

	header = (struct EEPROM_header *)&eeprom[0];
	if (header->magic[0] != k_EEPROM_magic0 ||
	    header->magic[1] != k_EEPROM_magic1) {
		fail("bad magic in EEPROM file");
	}
	if (header->revision != k_EEPROM_revision) {
		fail("unsupported EEPROM format revision");
	}
	printf("Header OK\n");

	index = sizeof(*header);
	for (;;) {
		uint8_t size;
		var = (struct Param_header *)&eeprom[index];
		if (var->key == _sentinal_key ||
		    var->group_element == _sentinal_group ||
		    var->type == _sentinal_type) {
			printf("end sentinel at %u\n", index);
			break;
		}
		size = type_size(var->type);
		printf("%04x: type %u (%s) key %u size %d\n ",
		       index, var->type, type_names[var->type], var->key, size);
		index += sizeof(*var);
		for (i = 0; i <= size; i++) {
			printf(" %02x", eeprom[index + i]);
		}
		printf("\n");
		index += size;
		if (index >= sizeof(eeprom)) {
			fflush(stdout);
			fail("missing end sentinel");
		}
	}
	return 0;
}