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 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_ */ 27