semihost.h 596 B

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. /*
  3. * Copyright (C) 2022 tinylab.org
  4. * Author: Bin Meng <bmeng@tinylab.org>
  5. */
  6. #ifndef _RISCV_SEMIHOST_H_
  7. #define _RISCV_SEMIHOST_H_
  8. struct uart_port;
  9. static inline void smh_putc(struct uart_port *port, unsigned char c)
  10. {
  11. asm volatile("addi a1, %0, 0\n"
  12. "addi a0, zero, 3\n"
  13. ".balign 16\n"
  14. ".option push\n"
  15. ".option norvc\n"
  16. "slli zero, zero, 0x1f\n"
  17. "ebreak\n"
  18. "srai zero, zero, 0x7\n"
  19. ".option pop\n"
  20. : : "r" (&c) : "a0", "a1", "memory");
  21. }
  22. #endif /* _RISCV_SEMIHOST_H_ */