main.cpp

00001 #include "mbed.h"
00002 
00003 LocalFileSystem fs ("fs");
00004 DigitalOut led1(LED1);
00005 DigitalOut led4(LED4);
00006 
00007 int main() {
00008 
00009     int ctr=32; // 32 because the fixed size of the vector table
00010     
00011     printf("File patcher\n");
00012 
00013     FILE *f1 = fopen("/fs/file.unp","rb"); // read binary
00014     FILE *f2 = fopen("/fs/file.pat","wb"); // write binary
00015 
00016     if (f1 == NULL) {
00017         printf("Cant open file for reading\n");
00018         while (1) {
00019             led1 = !led1;
00020             wait(0.2);
00021         }
00022     }
00023 
00024     else {
00025 
00026         unsigned int vector [8]; // storage for the vector table
00027         unsigned int sum = 0;    //
00028 
00029         // read first 7 words (28 bytes) into an array
00030         for (int i = 0; i < 8; i++) {
00031             vector[i] = 0; // zero the vector location
00032             for (int j = 0; j < 4; j++) {
00033                 char c = fgetc(f1);         // read char from file
00034                 vector[i]  |= (c << (8*j)); // shift to byte location
00035             }
00036             sum += vector[i]; // keep a running total
00037         }
00038 
00039 
00040         // calculate the 2's compliment, for vector[7]
00041         vector[7] = (~sum) + 1;
00042 
00043         for (int i = 0; i < 8; i++) {
00044             printf("Vector[%d] = 0x%08x\n",i,vector[i]);
00045         }
00046 
00047         printf("Sum vector = 0x%08x\n",sum);
00048 
00049 
00050         // write out patched vector table
00051         // read first 7 words (28 bytes) into an array
00052         for (int i = 0; i < 8; i++) {
00053             for (int j = 0; j < 4; j++) {
00054                 char c = ( vector[i] >> (8*j)) & 0xFF;
00055                 fputc(c,f2);         // read char from file
00056             }
00057         }
00058 
00059         // read in and write remaining bytes of source binary
00060         while (!feof(f1)) {
00061             char c = fgetc (f1);    // read char from file
00062             fputc(c,f2);            // write byte to file
00063             ctr++;
00064         }
00065 
00066     }
00067 
00068     fclose(f1);
00069     fclose(f2);
00070 
00071     printf("Done! %d bytes processed\n",ctr);
00072     while (1) {
00073         led4 = !led4;
00074         wait(0.2);
00075     }
00076 
00077 
00078 }