blob: 9be5bffd30124777c4f8110065e6cca5640312ac [file] [log] [blame]
Kautuk Consul1c03ab92022-12-07 17:12:34 +05301// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
4 * Copyright 2014 Broadcom Corporation
5 */
6
Kautuk Consul1c03ab92022-12-07 17:12:34 +05307#include <log.h>
8#include <semihosting.h>
Tom Rini467382c2023-12-14 13:16:58 -05009#include <linux/errno.h>
10#include <linux/string.h>
Kautuk Consul1c03ab92022-12-07 17:12:34 +053011
12#define SYSOPEN 0x01
13#define SYSCLOSE 0x02
14#define SYSWRITEC 0x03
15#define SYSWRITE0 0x04
16#define SYSWRITE 0x05
17#define SYSREAD 0x06
18#define SYSREADC 0x07
19#define SYSISERROR 0x08
20#define SYSSEEK 0x0A
21#define SYSFLEN 0x0C
22#define SYSERRNO 0x13
23
24#if CONFIG_IS_ENABLED(SEMIHOSTING_FALLBACK)
25static bool _semihosting_enabled = true;
26static bool try_semihosting = true;
27
28bool semihosting_enabled(void)
29{
30 if (try_semihosting) {
31 smh_trap(SYSERRNO, NULL);
32 try_semihosting = false;
33 }
34
35 return _semihosting_enabled;
36}
37
38void disable_semihosting(void)
39{
40 _semihosting_enabled = false;
41}
42#endif
43
44/**
45 * smh_errno() - Read the host's errno
46 *
47 * This gets the value of the host's errno and negates it. The host's errno may
48 * or may not be set, so only call this function if a previous semihosting call
49 * has failed.
50 *
51 * Return: a negative error value
52 */
53static int smh_errno(void)
54{
55 long ret = smh_trap(SYSERRNO, NULL);
56
57 if (ret > 0 && ret < INT_MAX)
58 return -ret;
59 return -EIO;
60}
61
62long smh_open(const char *fname, enum smh_open_mode mode)
63{
64 long fd;
65 struct smh_open_s {
66 const char *fname;
67 unsigned long mode;
68 size_t len;
69 } open;
70
71 debug("%s: file \'%s\', mode \'%u\'\n", __func__, fname, mode);
72
73 open.fname = fname;
74 open.len = strlen(fname);
75 open.mode = mode;
76
77 /* Open the file on the host */
78 fd = smh_trap(SYSOPEN, &open);
79 if (fd == -1)
80 return smh_errno();
81 return fd;
82}
83
84/**
85 * struct smg_rdwr_s - Arguments for read and write
86 * @fd: A file descriptor returned from smh_open()
87 * @memp: Pointer to a buffer of memory of at least @len bytes
88 * @len: The number of bytes to read or write
89 */
90struct smh_rdwr_s {
91 long fd;
92 void *memp;
93 size_t len;
94};
95
96long smh_read(long fd, void *memp, size_t len)
97{
98 long ret;
99 struct smh_rdwr_s read;
100
101 debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
102
103 read.fd = fd;
104 read.memp = memp;
105 read.len = len;
106
107 ret = smh_trap(SYSREAD, &read);
108 if (ret < 0)
109 return smh_errno();
110 return len - ret;
111}
112
113long smh_write(long fd, const void *memp, size_t len, ulong *written)
114{
115 long ret;
116 struct smh_rdwr_s write;
117
118 debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
119
120 write.fd = fd;
121 write.memp = (void *)memp;
122 write.len = len;
123
124 ret = smh_trap(SYSWRITE, &write);
125 *written = len - ret;
126 if (ret)
127 return smh_errno();
128 return 0;
129}
130
131long smh_close(long fd)
132{
133 long ret;
134
135 debug("%s: fd %ld\n", __func__, fd);
136
137 ret = smh_trap(SYSCLOSE, &fd);
138 if (ret == -1)
139 return smh_errno();
140 return 0;
141}
142
143long smh_flen(long fd)
144{
145 long ret;
146
147 debug("%s: fd %ld\n", __func__, fd);
148
149 ret = smh_trap(SYSFLEN, &fd);
150 if (ret == -1)
151 return smh_errno();
152 return ret;
153}
154
155long smh_seek(long fd, long pos)
156{
157 long ret;
158 struct smh_seek_s {
159 long fd;
160 long pos;
161 } seek;
162
163 debug("%s: fd %ld pos %ld\n", __func__, fd, pos);
164
165 seek.fd = fd;
166 seek.pos = pos;
167
168 ret = smh_trap(SYSSEEK, &seek);
169 if (ret)
170 return smh_errno();
171 return 0;
172}
173
174int smh_getc(void)
175{
176 return smh_trap(SYSREADC, NULL);
177}
178
179void smh_putc(char ch)
180{
181 smh_trap(SYSWRITEC, &ch);
182}
183
184void smh_puts(const char *s)
185{
186 smh_trap(SYSWRITE0, (char *)s);
187}