/*************************************************************************
  |  COPYRIGHT (c) 2000 BY ABATRON AG
  |*************************************************************************
  |
  |  PROJECT NAME: Linux Image to S-record Conversion Utility
  |  FILENAME    : img2srec.c
  |
  |  COMPILER    : GCC
  |
  |  TARGET OS   : LINUX / UNIX
  |  TARGET HW   : -
  |
  |  PROGRAMMER  : Abatron / RD
  |  CREATION    : 07.07.00
  |
  |*************************************************************************
  |
  |  DESCRIPTION :
  |
  |  Utility to convert a Linux Boot Image to S-record:
  |  ==================================================
  |
  |  This command line utility can be used to convert a Linux boot image
  |  (zimage.initrd) to S-Record format used for flash programming.
  |  This conversion takes care of the special sections "IMAGE" and INITRD".
  |
  |  img2srec [-o offset] image > image.srec
  |
  |
  |  Build the utility:
  |  ==================
  |
  |  To build the utility use GCC as follows:
  |
  |  gcc img2srec.c -o img2srec
  |
  |
  |*************************************************************************
  |
  |
  |  UPDATES     :
  |
  |  DATE      NAME  CHANGES
  |  -----------------------------------------------------------
  |  Latest update
  |
  |  07.07.00  aba   Initial release
  |
  |*************************************************************************/
  
  /*************************************************************************
  |  INCLUDES
  |*************************************************************************/

  #include "os_support.h"

  #include <stdbool.h>

  #include <stddef.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <ctype.h>
  #include <string.h>
  #include <elf.h>
  #include <unistd.h>
  #include <errno.h>

  /*************************************************************************

  |  FUNCTIONS
  |*************************************************************************/

  static char* ExtractHex (uint32_t* value,  char* getPtr)

  {

    uint32_t num;
    uint32_t digit;
    uint8_t  c;

  
    while (*getPtr == ' ') getPtr++;
    num = 0;
    for (;;) {
      c = *getPtr;

      if      ((c >= '0') && (c <= '9')) digit = (uint32_t)(c - '0');
      else if ((c >= 'A') && (c <= 'F')) digit = (uint32_t)(c - 'A' + 10);
      else if ((c >= 'a') && (c <= 'f')) digit = (uint32_t)(c - 'a' + 10);

      else break;
      num <<= 4;
      num += digit;
      getPtr++;
    } /* for */
    *value = num;
    return getPtr;
  } /* ExtractHex */

  static char* ExtractDecimal (uint32_t* value,  char* getPtr)

  {

    uint32_t num;
    uint32_t digit;
    uint8_t  c;

  
    while (*getPtr == ' ') getPtr++;
    num = 0;
    for (;;) {
      c = *getPtr;

      if      ((c >= '0') && (c <= '9')) digit = (uint32_t)(c - '0');

      else break;
      num *= 10;
      num += digit;
      getPtr++;
    } /* for */
    *value = num;
    return getPtr;
  } /* ExtractDecimal */

  static void ExtractNumber (uint32_t* value,  char* getPtr)

  {

    bool  neg = false;

  
    while (*getPtr == ' ') getPtr++;
    if (*getPtr == '-') {

      neg = true;

      getPtr++;
    } /* if */
    if ((*getPtr == '0') && ((*(getPtr+1) == 'x') || (*(getPtr+1) == 'X'))) {
      getPtr +=2;
      (void)ExtractHex(value, getPtr);
    } /* if */
    else {
      (void)ExtractDecimal(value, getPtr);
    } /* else */
    if (neg) *value = -(*value);
  } /* ExtractNumber */

  static uint8_t* ExtractWord(uint16_t* value, uint8_t* buffer)

  {

    uint16_t x;
    x = (uint16_t)*buffer++;
    x = (x<<8) + (uint16_t)*buffer++;

    *value = x;
    return buffer;
  } /* ExtractWord */

  static uint8_t* ExtractLong(uint32_t* value, uint8_t* buffer)

  {

    uint32_t x;
    x = (uint32_t)*buffer++;
    x = (x<<8) + (uint32_t)*buffer++;
    x = (x<<8) + (uint32_t)*buffer++;
    x = (x<<8) + (uint32_t)*buffer++;

    *value = x;
    return buffer;
  } /* ExtractLong */

  static uint8_t* ExtractBlock(uint16_t count, uint8_t* data, uint8_t* buffer)

  {
    while (count--) *data++ = *buffer++;
    return buffer;
  } /* ExtractBlock */

  static char* WriteHex(char* pa, uint8_t value, uint16_t* pCheckSum)

  {

    uint16_t  temp;

  
    static  char ByteToHex[] = "0123456789ABCDEF";
  
    *pCheckSum += value;
    temp  = value / 16;
    *pa++ = ByteToHex[temp];
    temp  = value % 16;
    *pa++ = ByteToHex[temp];
    return pa;
  }

  static char* BuildSRecord(char* pa, uint16_t sType, uint32_t addr,
  			  const uint8_t* data, int nCount)

  {

    uint16_t  addrLen;
    uint16_t  sRLen;
    uint16_t  checkSum;
    uint16_t  i;

  
    switch (sType) {
    case 0:
    case 1:
    case 9:
      addrLen = 2;
      break;
    case 2:
    case 8:
      addrLen = 3;
      break;
    case 3:
    case 7:
      addrLen = 4;
      break;
    default:
      return pa;
    } /* switch */
  
    *pa++ = 'S';
    *pa++ = (char)(sType + '0');
    sRLen = addrLen + nCount + 1;
    checkSum = 0;

    pa = WriteHex(pa, (uint8_t)sRLen, &checkSum);

  
    /* Write address field */
    for (i = 1; i <= addrLen; i++) {

      pa = WriteHex(pa, (uint8_t)(addr >> (8 * (addrLen - i))), &checkSum);

    } /* for */
  
    /* Write code/data fields */
    for (i = 0; i < nCount; i++) {
      pa = WriteHex(pa, *data++, &checkSum);
    } /* for */
  
    /* Write checksum field */
    checkSum = ~checkSum;

    pa = WriteHex(pa, (uint8_t)checkSum, &checkSum);

    *pa++ = '\0';
    return pa;
  }

  static void ConvertELF(char* fileName, uint32_t loadOffset)

  {
    FILE*         file;
    int           i;
    int           rxCount;

    uint8_t          rxBlock[1024];
    uint32_t         loadSize;
    uint32_t         firstAddr;
    uint32_t         loadAddr;
    uint32_t         loadDiff = 0;

    Elf32_Ehdr    elfHeader;
    Elf32_Shdr    sectHeader[32];

    uint8_t*         getPtr;

    char          srecLine[128];
    char		*hdr_name;
  
  
    /* open file */
    if ((file = fopen(fileName,"rb")) == NULL) {
      fprintf (stderr, "Can't open %s: %s
  ", fileName, strerror(errno));
      return;
    } /* if */
  
    /* read ELF header */
    rxCount = fread(rxBlock, 1, sizeof elfHeader, file);
    getPtr = ExtractBlock(sizeof elfHeader.e_ident, elfHeader.e_ident, rxBlock);
    getPtr = ExtractWord(&elfHeader.e_type, getPtr);
    getPtr = ExtractWord(&elfHeader.e_machine, getPtr);

    getPtr = ExtractLong((uint32_t *)&elfHeader.e_version, getPtr);
    getPtr = ExtractLong((uint32_t *)&elfHeader.e_entry, getPtr);
    getPtr = ExtractLong((uint32_t *)&elfHeader.e_phoff, getPtr);
    getPtr = ExtractLong((uint32_t *)&elfHeader.e_shoff, getPtr);
    getPtr = ExtractLong((uint32_t *)&elfHeader.e_flags, getPtr);

    getPtr = ExtractWord(&elfHeader.e_ehsize, getPtr);
    getPtr = ExtractWord(&elfHeader.e_phentsize, getPtr);
    getPtr = ExtractWord(&elfHeader.e_phnum, getPtr);
    getPtr = ExtractWord(&elfHeader.e_shentsize, getPtr);
    getPtr = ExtractWord(&elfHeader.e_shnum, getPtr);
    getPtr = ExtractWord(&elfHeader.e_shstrndx, getPtr);
    if (    (rxCount              != sizeof elfHeader)
         || (elfHeader.e_ident[0] != ELFMAG0)
         || (elfHeader.e_ident[1] != ELFMAG1)
         || (elfHeader.e_ident[2] != ELFMAG2)
         || (elfHeader.e_ident[3] != ELFMAG3)
         || (elfHeader.e_type     != ET_EXEC)
       ) {
      fclose(file);
      fprintf (stderr, "*** illegal file format
  ");
      return;
    } /* if */
  
    /* read all section headers */
    fseek(file, elfHeader.e_shoff, SEEK_SET);
    for (i = 0; i < elfHeader.e_shnum; i++) {
      rxCount = fread(rxBlock, 1, sizeof sectHeader[0], file);

      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_name, rxBlock);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_type, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_flags, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_addr, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_offset, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_size, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_link, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_info, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_addralign, getPtr);
      getPtr = ExtractLong((uint32_t *)&sectHeader[i].sh_entsize, getPtr);

      if (rxCount != sizeof sectHeader[0]) {
        fclose(file);
        fprintf (stderr, "*** illegal file format
  ");
        return;
      } /* if */
    } /* for */
  
    if ((hdr_name = strrchr(fileName, '/')) == NULL) {
      hdr_name = fileName;
    } else {
      ++hdr_name;
    }
    /* write start record */

    (void)BuildSRecord(srecLine, 0, 0, (uint8_t *)hdr_name, strlen(hdr_name));

    printf("%s\r
  ",srecLine);
  
    /* write data records */
    firstAddr = ~0;
    loadAddr  =  0;
    for (i = 0; i < elfHeader.e_shnum; i++) {
      if (    (sectHeader[i].sh_type == SHT_PROGBITS)

  	 && (sectHeader[i].sh_size != 0)
  	 ) {

        loadSize = sectHeader[i].sh_size;
        if (sectHeader[i].sh_flags != 0) {

  	loadAddr = sectHeader[i].sh_addr;
  	loadDiff = loadAddr - sectHeader[i].sh_offset;

        } /* if */
        else {

  	loadAddr = sectHeader[i].sh_offset + loadDiff;

        } /* else */
  
        if (loadAddr < firstAddr)

  	firstAddr = loadAddr;

  
        /* build s-records */
        loadSize = sectHeader[i].sh_size;
        fseek(file, sectHeader[i].sh_offset, SEEK_SET);
        while (loadSize) {

  	rxCount = fread(rxBlock, 1, (loadSize > 32) ? 32 : loadSize, file);
  	if (rxCount < 0) {
  	  fclose(file);
  	  fprintf (stderr, "*** illegal file format
  ");
  	return;
  	} /* if */
  	(void)BuildSRecord(srecLine, 3, loadAddr + loadOffset, rxBlock, rxCount);
  	loadSize -= rxCount;
  	loadAddr += rxCount;
  	printf("%s\r
  ",srecLine);

        } /* while */
      } /* if */
    } /* for */
  
    /* add end record */
    (void)BuildSRecord(srecLine, 7, firstAddr + loadOffset, 0, 0);
    printf("%s\r
  ",srecLine);
    fclose(file);
  } /* ConvertELF */
  
  
  /*************************************************************************
  |  MAIN
  |*************************************************************************/
  
  int main( int argc, char *argv[ ])
  {

    uint32_t offset;

  
    if (argc == 2) {
      ConvertELF(argv[1], 0);
    } /* if */
    else if ((argc == 4) && (strcmp(argv[1], "-o") == 0)) {
      ExtractNumber(&offset, argv[2]);
      ConvertELF(argv[3], offset);
    } /* if */
    else {
      fprintf (stderr, "Usage: img2srec [-o offset] <image>
  ");
    } /* if */
  
    return 0;
  } /* main */