Merge remote-tracking branch 'remotes/dg-gitlab/tags/ppc-for-6.0-20210412' into staging
[qemu.git] / linux-user / semihost.c
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 }