Linux USB驱动（3）---Intel Hex文件解析

CY68013使用的固件是Intel的HEX格式的文件，文件的格式如下:

:[LL][ADDR][TYPE][DATA][CHKSUM]

: --- 1字节 标示一个有效的HEX记录的开始

LL --- 2字节 记录中有效数据（DATA）的字节数

ADDR --- 4字节 数据（data）需要下载到内存中的地址

TYPE --- 2字节 标示数据是否结束，00正常数据，01结束

DATA --- LL字节 数据,大小有LL指定

CHKSUM --- 2字节 整个HEX记录的校验和

校验和的计算公式如下，HEX是ASCII文本，需要将以上的数据转换为二进制格式再处理：

CHKSUM = ~(LL + ADDR高8位 + ADDR低8位 + TYPE + DATA) + 1

  6 typedef struct{
  7 unsigned char size; /* Hex data size */
  8 unsigned char type; /* Hex data type */
  9 unsigned short addr; /* Downloader address */
 10 unsigned char data[256]; /* Hex data */
 11 }HEX_INFO, *P_HEX_INFO;



 15 /* Conversion ascii code to hex data */
 16 static unsigned char ascii_to_hex(const unsigned char n)
 17 {
 18 if (n >= '0' && n <= '9')
 19 return n - '0';
 20 else if (n >= 'A' && n <= 'F')
 21 return n - ('A' - 10);
 22 else if (n >= 'a' && n <= 'f')
 23 return n - ('a' - 10);
 24
 25 return 0;
 26 }


 28 /*******************************************************
 29 Desc : Parse a hex recode specified by recode
 30 cache the result to hex struct
 31 recode : which hex recode need parse
 32 hex : after parse hex recode
 33 result : 0 success recode in hex
 34 1 it was not a hex recode
 35 2 recode lengrh have error
 36 3 recode check sum have error
 37 *******************************************************/
 38 static unsigned int parse_hex(const char *recode, P_HEX_INFO hex)
 39 {
 40
 41 const char *src = recode;
 42 unsigned char buf[256];
 43 unsigned int chksum, recode_chksum;
 44 unsigned int idx = 0, cnt, total;
 45
 46 /* It was not a hex recode */
 47 if (*src != ':'){
 48 return 1;
 49 }
 50
 51 /* Move to read data */
 52 src++;
 53 bzero(buf, sizeof(buf));
 54
 55 /* Conversion ascii data to hex */
 56 for (idx = 0; *src; src++, idx++){
 57
 58 buf[idx] = ascii_to_hex(*src);
 59 }
 60
 61 /* Hex data total */
 62 total = idx;
 63
 64 /* Get data size length and check */
 65 hex->size = (buf[0] << 4) | buf[1];
 66
 67 if (!(hex->size >= 0 && hex->size < 256))return 2;
 68
 69 /* Get download addr */
 70 hex->addr = (buf[2] << 12) | (buf[3] << 8) | (buf[4] << 4) | buf[5];
 71
 72 /* Get this line data type */
 73 hex->type = (buf[6] << 4) | buf[7];
 74
 75 /* Get data and calc each of the chksum */
 76 chksum = hex->size + hex->addr + (hex->addr >> 8) + hex->type;

 77
 78 for (cnt = 0, idx = 8; (cnt < hex->size) && (idx < total);){
 79
 80 hex->data[cnt] = (buf[idx] << 4) | buf[idx + 1];
 81
 82 chksum += hex->data[cnt];
 83 cnt ++;
 84 idx += 2;
 85 }
 86
 87 /* Get file chksum */
 88 recode_chksum = (buf[idx] << 4) | buf[idx + 1];
 89
 90 /* Check total check sum */
 91 if ((recode_chksum + chksum) & 0xff)return 3;
 92
 93 return 0;
 94 }