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 "user-internals.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 /* 37 * For linux-user we can safely block. However as we want to return as 38 * soon as a character is read we need to tweak the termio to disable 39 * line buffering. We restore the old mode afterwards in case the 40 * program is expecting more normal behaviour. This is slow but 41 * nothing using semihosting console reading is expecting to be fast. 42 */ 43 int qemu_semihosting_console_read(CPUState *cs, void *buf, int len) 44 { 45 int ret; 46 struct termios old_tio, new_tio; 47 48 /* Disable line-buffering and echo */ 49 tcgetattr(STDIN_FILENO, &old_tio); 50 new_tio = old_tio; 51 new_tio.c_lflag &= (~ICANON & ~ECHO); 52 new_tio.c_cc[VMIN] = 1; 53 new_tio.c_cc[VTIME] = 0; 54 tcsetattr(STDIN_FILENO, TCSANOW, &new_tio); 55 56 ret = fread(buf, 1, len, stdin); 57 58 /* restore config */ 59 tcsetattr(STDIN_FILENO, TCSANOW, &old_tio); 60 61 return ret; 62 } 63 64 int qemu_semihosting_console_write(void *buf, int len) 65 { 66 return fwrite(buf, 1, len, stderr); 67 } 68