1 | /* |
2 | * Semihosting Console Support |
3 | * |
4 | * Copyright (c) 2015 Imagination Technologies |
5 | * Copyright (c) 2019 Linaro Ltd |
6 | * |
7 | * This provides support for outputting to a semihosting console. |
8 | * |
9 | * While most semihosting implementations support reading and writing |
10 | * to arbitrary file descriptors we treat the console as something |
11 | * specifically for debugging interaction. This means messages can be |
12 | * re-directed to gdb (if currently being used to debug) or even |
13 | * re-directed elsewhere. |
14 | * |
15 | * SPDX-License-Identifier: GPL-2.0-or-later |
16 | */ |
17 | |
18 | #include "qemu/osdep.h" |
19 | #include "cpu.h" |
20 | #include "hw/semihosting/semihost.h" |
21 | #include "hw/semihosting/console.h" |
22 | #include "exec/gdbstub.h" |
23 | #include "qemu/log.h" |
24 | #include "chardev/char.h" |
25 | |
26 | int qemu_semihosting_log_out(const char *s, int len) |
27 | { |
28 | Chardev *chardev = semihosting_get_chardev(); |
29 | if (chardev) { |
30 | return qemu_chr_write_all(chardev, (uint8_t *) s, len); |
31 | } else { |
32 | return write(STDERR_FILENO, s, len); |
33 | } |
34 | } |
35 | |
36 | /* |
37 | * A re-implementation of lock_user_string that we can use locally |
38 | * instead of relying on softmmu-semi. Hopefully we can deprecate that |
39 | * in time. Copy string until we find a 0 or address error. |
40 | */ |
41 | static GString *copy_user_string(CPUArchState *env, target_ulong addr) |
42 | { |
43 | CPUState *cpu = env_cpu(env); |
44 | GString *s = g_string_sized_new(128); |
45 | uint8_t c; |
46 | |
47 | do { |
48 | if (cpu_memory_rw_debug(cpu, addr++, &c, 1, 0) == 0) { |
49 | s = g_string_append_c(s, c); |
50 | } else { |
51 | qemu_log_mask(LOG_GUEST_ERROR, |
52 | "%s: passed inaccessible address " TARGET_FMT_lx, |
53 | __func__, addr); |
54 | break; |
55 | } |
56 | } while (c!=0); |
57 | |
58 | return s; |
59 | } |
60 | |
61 | static void semihosting_cb(CPUState *cs, target_ulong ret, target_ulong err) |
62 | { |
63 | if (ret == (target_ulong) -1) { |
64 | qemu_log("%s: gdb console output failed (" TARGET_FMT_ld")" , |
65 | __func__, err); |
66 | } |
67 | } |
68 | |
69 | int qemu_semihosting_console_outs(CPUArchState *env, target_ulong addr) |
70 | { |
71 | GString *s = copy_user_string(env, addr); |
72 | int out = s->len; |
73 | |
74 | if (use_gdb_syscalls()) { |
75 | gdb_do_syscall(semihosting_cb, "write,2,%x,%x" , addr, s->len); |
76 | } else { |
77 | out = qemu_semihosting_log_out(s->str, s->len); |
78 | } |
79 | |
80 | g_string_free(s, true); |
81 | return out; |
82 | } |
83 | |
84 | void qemu_semihosting_console_outc(CPUArchState *env, target_ulong addr) |
85 | { |
86 | CPUState *cpu = env_cpu(env); |
87 | uint8_t c; |
88 | |
89 | if (cpu_memory_rw_debug(cpu, addr, &c, 1, 0) == 0) { |
90 | if (use_gdb_syscalls()) { |
91 | gdb_do_syscall(semihosting_cb, "write,2,%x,%x" , addr, 1); |
92 | } else { |
93 | qemu_semihosting_log_out((const char *) &c, 1); |
94 | } |
95 | } else { |
96 | qemu_log_mask(LOG_GUEST_ERROR, |
97 | "%s: passed inaccessible address " TARGET_FMT_lx, |
98 | __func__, addr); |
99 | } |
100 | } |
101 | |