arch/riscv/include/asm/semihost.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2022 tinylab.org
   4  * Author: Bin Meng <[email protected]>
   5  */
   6
   7 #ifndef _RISCV_SEMIHOST_H_
   8 #define _RISCV_SEMIHOST_H_
   9
  10 struct uart_port;
  11
  12 static inline void smh_putc(struct uart_port *port, unsigned char c)
  13 {
  14         asm volatile("addi    a1, %0, 0\n"
  15                      "addi    a0, zero, 3\n"
  16                      ".balign 16\n"
  17                      ".option push\n"
  18                      ".option norvc\n"
  19                      "slli    zero, zero, 0x1f\n"
  20                      "ebreak\n"
  21                      "srai    zero, zero, 0x7\n"
  22                      ".option pop\n"
  23                      : : "r" (&c) : "a0", "a1", "memory");
  24 }
  25
  26 #endif /* _RISCV_SEMIHOST_H_ */