started impl allocation

kpack_c.c

@@ -14,6 +14,11 @@ static void error_load_infile() {
     exit(1);
 }
 
+static void error_malloc_failed() {
+    printf("Error: memory allocation failed\n");
+    exit(1);
+}
+
 int main(int argc, char *argv[])
 {
     bool flag_nologo = false;
@@ -44,7 +49,7 @@ int main(int argc, char *argv[])
                 return 1;
         }
     }
-    // Check for required infile
+    // check for required infile
     if (optind >= argc) {
         printf("Error: Input file is required.\n");
         printf(str_usage, argv[0]);
@@ -52,7 +57,7 @@ int main(int argc, char *argv[])
     }
     infile_name = argv[optind];
 
-    // Optional outfile
+    // optional outfile
     if (optind + 1 < argc) {
         outfile_name = argv[optind + 1];
         optind++;
@@ -98,8 +103,7 @@ int main(int argc, char *argv[])
 
     unsigned char *infile_buf = malloc(infile_size);
     if (infile_buf == NULL) {
-        printf("Error: memory allocation failed\n");
-        return 1;
+        error_malloc_failed();
     }
     size_t bytes_read = fread(infile_buf, 1, infile_size, infile_handle);
     if (bytes_read != infile_size) {
@@ -107,9 +111,16 @@ int main(int argc, char *argv[])
     }
     fclose(infile_handle);
 
-    // printf("file contents = %s\n", infile_buf);
+    // calculate maximum size of the output:
+    unsigned bufsize = infile_size*9/8 + 0x400; // should be enough for header
+    printf("bufsize = 0x%x\n", bufsize);
+    unsigned char *buf = malloc(2*bufsize); // allocate memory for two copies of maximum output
+    if (buf == NULL) {
+        error_malloc_failed();
+    }
 
     // TODO ...
+    // https://git.kolibrios.org/KolibriOS/kolibrios/src/commit/293e1d195a14d01a0f8812a954ff1449048f6209/programs/other/kpack/kerpack_linux/kpack64.asm#L236
 
     return 0;
 }