reg.cc

#include <cstdint>

template <class Address, class Register, Address address>
struct reg_t {
  static inline void write(Register value) {
    *reinterpret_cast<volatile Address*>(address) = value;
  }

  static inline Register read() {
    return *reinterpret_cast<volatile Address*>(address);
  }
};

template <uint32_t address>
using reg32_t = reg_t<uint32_t, uint32_t, address>;

using GPFSEL1 = reg32_t<0x20200004>;
using GPSET0  = reg32_t<0x2020001c>;

auto main() -> int {
  // GPIO18の動作モードをOutputにする
  GPFSEL1::write(1 << (3 * 8));

  // GPIO18をHighにする
  GPSET0::write(1 << 18);

  while (1) {}
}