semihost.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * Copyright (C) 2022 tinylab.org
 4 * Author: Bin Meng <bmeng@tinylab.org>
 5 */
 6
 7#ifndef _RISCV_SEMIHOST_H_
 8#define _RISCV_SEMIHOST_H_
 9
10struct uart_port;
11
12static 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_ */