How do I read BMP file header directly to type?

[HonzsSedlomn]

Hello, I'm trying to load BMP file header to type using FileStream readData, 
but it doesn't work. I have to read every single variable separately. If I try 
to load it with readData, there is some weird result, missing data, etc.
    
    
    type
        BitmapFileHeader* = object
            signature*: array[2, char]
            size*: uint32
            reservedOne*: uint16
            reservedTwo*: uint16
            offset*: uint32
    
    proc loadBitmapFileHeader*(bitmap: Bitmap, file: FileStream): 
BitmapFileHeader =
        file.setPosition(0)
        
        result.signature[0] = file.readChar()
        result.signature[1] = file.readChar()
        result.size = file.readUint32()
        result.reservedOne = file.readUint16()
        result.reservedTwo = file.readUint16()
        result.offset = file.readUint32()
        
        #TODO: Check if all bytes have been read
        
        return result
    

Is there any way to load it like this?
    
    
    proc loadBitmapFileHeader*(bitmap: Bitmap, file: FileStream): 
BitmapFileHeader =
        file.setPosition(0)
        
        let readBytes = file.readData(bitmap.fileHeader.addr, 14)
        
        return result