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 "cpu.h" 15 #include "hw/semihosting/console.h" 16 #include "qemu.h" 17 #include <termios.h> 18 19 int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr) 20 { 21 int len = target_strlen(addr); 22 void *s; 23 if (len < 0){ 24 qemu_log_mask(LOG_GUEST_ERROR, 25 "%s: passed inaccessible address " TARGET_FMT_lx, 26 __func__, addr); 27 return 0; 28 } 29 s = lock_user(VERIFY_READ, addr, (long)(len + 1), 1); 30 g_assert(s); /* target_strlen has already verified this will work */ 31 len = write(STDERR_FILENO, s, len); 32 unlock_user(s, addr, 0); 33 return len; 34 } 35 36 void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr) 37 { 38 char c; 39 40 if (get_user_u8(c, addr)) { 41 qemu_log_mask(LOG_GUEST_ERROR, 42 "%s: passed inaccessible address " TARGET_FMT_lx, 43 __func__, addr); 44 } else { 45 if (write(STDERR_FILENO, &c, 1) != 1) { 46 qemu_log_mask(LOG_UNIMP, "%s: unexpected write to stdout failure", 47 __func__); 48 } 49 } 50 } 51 52 /* 53 * For linux-user we can safely block. However as we want to return as 54 * soon as a character is read we need to tweak the termio to disable 55 * line buffering. We restore the old mode afterwards in case the 56 * program is expecting more normal behaviour. This is slow but 57 * nothing using semihosting console reading is expecting to be fast. 58 */ 59 target_ulong qemu_semihosting_console_inc(CPUArchState *env) 60 { 61 uint8_t c; 62 struct termios old_tio, new_tio; 63 64 /* Disable line-buffering and echo */ 65 tcgetattr(STDIN_FILENO, &old_tio); 66 new_tio = old_tio; 67 new_tio.c_lflag &= (~ICANON & ~ECHO); 68 tcsetattr(STDIN_FILENO, TCSANOW, &new_tio); 69 70 c = getchar(); 71 72 /* restore config */ 73 tcsetattr(STDIN_FILENO, TCSANOW, &old_tio); 74 75 return (target_ulong) c; 76 } 77