import argparse

def main():
    p = argparse.ArgumentParser()
    p.add_argument('--file', required=True)
    p.add_argument('--addr', required=True)
    p.add_argument('--base', type=lambda x: int(x,0), default=0x80000000)
    p.add_argument('--stride', type=int, default=10)
    p.add_argument('--field_idx', type=int, default=9)
    p.add_argument('--count', type=int, default=20)
    args = p.parse_args()

    addr = int(args.addr, 0)
    offset = addr - args.base
    with open(args.file, 'rb') as f:
        for ch in range(args.count):
            idx = offset + ch*args.stride + args.field_idx
            f.seek(idx)
            b = f.read(1)
            if not b:
                print(f"ch {ch:02d}: EOF")
                break
            print(f"ch {ch:02d}: addr {hex(addr + ch*args.stride + args.field_idx)} offset {hex(idx)} value {b[0]:02x} ({b[0]})")

if __name__ == '__main__':
    main()