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//convert.c by Steve Rhoads 4/26/01

//set $gp and zero .sbss and .bss

#include <stdio.h>

#include <stdlib.h>

#define BUF_SIZE (1024*1024)

#define ntohl(A) ((A>>24)|((A&0x00ff0000)>>8)|((A&0xff00)<<8)|(A<<24))

enum {

   TEXT_OFFSET,  TEXT_LENGTH,

   RDATA_OFFSET, RDATA_LENGTH,

   DATA_OFFSET,  DATA_LENGTH,

   SDATA_OFFSET, SDATA_LENGTH,

   SBSS_OFFSET,  SBSS_LENGTH,

   BSS_OFFSET,   BSS_LENGTH

};

long code_start_offset=0x60;

unsigned long map[12];

long offset[]={

   0x58, 0x5c,  //.text offset,length

   0x80, 0x84,  //.rdata offset,length

   0xa8, 0xac,  //.data offset,length

   0xd0, 0xd4,  //.sdata offset,length

   0xf8, 0xfc,  //.sbss offset,length

   0x120,0x124  //.bss offset,length

};

unsigned long load(char *ptr,unsigned long address)

{

   unsigned long value;

   value=*(unsigned long*)(ptr+address);

   value=ntohl(value);

   return value;

}

void set_low(char *ptr,unsigned long address,unsigned long value)

{

   unsigned long opcode;

   opcode=*(unsigned long*)(ptr+address);

   opcode=ntohl(opcode);

   opcode=(opcode&0xffff0000)|(value&0xffff);

   opcode=ntohl(opcode);

   *(unsigned long*)(ptr+address)=opcode;

}

int main(int argc,char *argv[])

{

   FILE *infile,*outfile,*txtfile;

   unsigned char *buf,*code;

   long size,code_offset;

   unsigned long i,d,gp_ptr;

   printf("test.exe -> code.txt & test2.exe\n");

   infile=fopen("test.exe","rb");

   if(infile==NULL) {

      printf("Can't open test.exe");

      return 0;

   }

   buf=(unsigned char*)malloc(BUF_SIZE);

   size=fread(buf,1,BUF_SIZE,infile);

   fclose(infile);

   code_offset=load(buf,code_start_offset);

   printf("code_offset=0x%x\n",code_offset);

   code=buf+code_offset;

   /*load all of the segment offsets and lengths*/

   for(i=0;i<12;++i) {

      map[i]=load(buf,offset[i]);

   }

   if(code_offset<0x120) {

      printf("no .sdata\n");

      for(i=6;i<12;i+=2) {

         map[i]=map[4];

         map[i+1]=map[5];

      }

   } else if(code_offset<0x140) {

      printf("no .rdata\n");

      for(i=11;i>4;--i) {

         map[i]=map[i-2];

      }

   }

   for(i=0;i<12;i+=2) {

      printf("0x%x 0x%x\n",map[i],map[i+1]);

   }

   /*Initialize the $gp register for sdata and sbss*/

   gp_ptr=map[SDATA_OFFSET]+0x8000;

   printf("gp_ptr=0x%x\n",gp_ptr);

   /*modify the first opcodes in boot.asm*/

   /*modify the lui opcode*/

   set_low(code,0,gp_ptr>>16);

   /*modify the ori opcode*/

   set_low(code,4,gp_ptr&0xffff);

   /*Clear .sbss and .bss*/

   printf(".sbss=0x%x .bss_end=0x%x\n",

      map[SBSS_OFFSET],map[BSS_OFFSET]+map[BSS_LENGTH]);

   set_low(code,8,map[SBSS_OFFSET]);

   set_low(code,12,map[BSS_OFFSET]+map[BSS_LENGTH]);

   /*write out code.txt*/

   outfile=fopen("test2.exe","wb");

   txtfile=fopen("code.txt","w");

   for(i=0;i<=map[SDATA_OFFSET]+map[SDATA_LENGTH];i+=4) {

      d=load(code,i);

      fprintf(txtfile,"%8.8x\n",d);

      fwrite(code+i,4,1,outfile);

   }

   fclose(outfile);

   fclose(txtfile);

   free(buf);

   return 0;

}