1 /* 2 * ARM Compatible Semihosting Console Support. 3 * 4 * Copyright (c) 2019 Linaro Ltd 5 * 6 * Currently ARM and RISC-V are unique in having support for 7 * semihosting support in linux-user. So for now we implement the 8 * common console API but just for arm and risc-v linux-user. 9 * 10 * SPDX-License-Identifier: GPL-2.0-or-later 11 */ 12 13 #include "qemu/osdep.h" 14 #include "semihosting/console.h" 15 #include "qemu.h" 16 #include <termios.h> 17 18 int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr) 19 { 20 int len = target_strlen(addr); 21 void *s; 22 if (len < 0){ 23 qemu_log_mask(LOG_GUEST_ERROR, 24 "%s: passed inaccessible address " TARGET_FMT_lx, 25 __func__, addr); 26 return 0; 27 } 28 s = lock_user(VERIFY_READ, addr, (long)(len + 1), 1); 29 g_assert(s); /* target_strlen has already verified this will work */ 30 len = write(STDERR_FILENO, s, len); 31 unlock_user(s, addr, 0); 32 return len; 33 } 34 35 void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr) 36 { 37 char c; 38 39 if (get_user_u8(c, addr)) { 40 qemu_log_mask(LOG_GUEST_ERROR, 41 "%s: passed inaccessible address " TARGET_FMT_lx, 42 __func__, addr); 43 } else { 44 if (write(STDERR_FILENO, &c, 1) != 1) { 45 qemu_log_mask(LOG_UNIMP, "%s: unexpected write to stdout failure", 46 __func__); 47 } 48 } 49 } 50 51 /* 52 * For linux-user we can safely block. However as we want to return as 53 * soon as a character is read we need to tweak the termio to disable 54 * line buffering. We restore the old mode afterwards in case the 55 * program is expecting more normal behaviour. This is slow but 56 * nothing using semihosting console reading is expecting to be fast. 57 */ 58 target_ulong qemu_semihosting_console_inc(CPUArchState *env) 59 { 60 uint8_t c; 61 struct termios old_tio, new_tio; 62 63 /* Disable line-buffering and echo */ 64 tcgetattr(STDIN_FILENO, &old_tio); 65 new_tio = old_tio; 66 new_tio.c_lflag &= (~ICANON & ~ECHO); 67 tcsetattr(STDIN_FILENO, TCSANOW, &new_tio); 68 69 c = getchar(); 70 71 /* restore config */ 72 tcsetattr(STDIN_FILENO, TCSANOW, &old_tio); 73 74 return (target_ulong) c; 75 } 76