vm_t *VM_Create( const char *module, int (*systemCalls)(int *),
vmInterpret_t interpret ) {
vmHeader_t *header;
...
length = FS_ReadFile( filename, (void **)&header );
...
// validate
if ( header->vmMagic != VM_MAGIC
|| header->bssLength < 0
|| header->dataLength < 0
|| header->litLength < 0
|| header->codeLength <= 0 ) {
VM_Free( vm );
Com_Error( ERR_FATAL, "%s has bad header", filename );
}

#define VM_MAGIC 0x12721444
typedef struct {
int vmMagic;
int instructionCount;
int codeOffset;
int codeLength;
int dataOffset;
int dataLength;
int litLength; // ( dataLength - litLength ) should be byteswapped on load
int bssLength; // zero filled memory appended to datalength
} vmHeader_t;

int FS_ReadFile( const char *qpath, void **buffer ) {
byte* buf;
...
int len;
...
// look for it in the filesystem or pack files
len = FS_FOpenFileRead( qpath, &h, qfalse );
....
fs_loadCount++;
fs_loadStack++;

buf = Hunk_AllocateTempMemory(len+1);
*buffer = buf;

FS_Read (buf, len, h);

// guarantee that it will have a trailing 0 for string operations
buf[len] = 0;
FS_FCloseFile( h );
....
return len;
}