Function sys_tty_write

kernel/cellos/src/sys_tty.cpp:88–188

std::string dump_useful_thread_info();

error_code sys_tty_write([[maybe_unused]] ppu_thread &ppu, s32 ch,
                         vm::cptr<char> buf, u32 len, vm::ptr<u32> pwritelen) {
  ppu.state += cpu_flag::wait;

  sys_tty.notice("sys_tty_write(ch=%d, buf=*0x%x, len=%d, pwritelen=*0x%x)", ch,
                 buf, len, pwritelen);

  std::string msg;

  if (static_cast<s32>(len) > 0 &&
      vm::check_addr(buf.addr(), vm::page_readable, len)) {
    msg.resize(len);

    if (!vm::try_access(buf.addr(), msg.data(), len, false)) {
      msg.clear();
    }
  }

  auto find_word = [](std::string_view msg, std::string_view word) -> bool {
    // Match uppercase and lowercase starting words
    const usz index = msg.find(word.substr(1));

    if (index != umax && index >= 1u) {
      return std::tolower(static_cast<u8>(msg[index - 1])) == word[0];
    }

    return false;
  };

  std::string_view sample = std::string_view(msg).substr(0, 1024);

  const bool warning =
      find_word(sample, "failed"sv) || find_word(sample, "abort"sv) ||
      find_word(sample, "crash"sv) || find_word(sample, "error"sv) ||
      find_word(sample, "unexpected"sv) || find_word(sample, "0x8001"sv);

  sample = {}; // Remove reference to string

  if (msg.size() >= 2u && [&]() {
        static thread_local u64 last_write = 0;

        // Dump thread about every period which TTY was not being touched for
        // about half a second
        const u64 current = get_system_time();
        return current - std::exchange(last_write, current) >=
               (warning ? 500'000 : 3'000'000);
      }()) {
    ppu_log.notice("\n%s", dump_useful_thread_info());
  }

  // Hack: write to tty even on CEX mode, but disable all error checks
  if (ch < 0 || ch > 15) {
    if (g_cfg.core.debug_console_mode) {
      return CELL_EINVAL;
    } else {
      msg.clear();
    }
  }