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Darwin Rambo261d2762014-06-09 11:12:59 -07001/*
2 * Copyright 2014 Broadcom Corporation
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7/*
8 * Minimal semihosting implementation for reading files into memory. If more
9 * features like writing files or console output are required they can be
10 * added later. This code has been tested on arm64/aarch64 fastmodel only.
11 * An untested placeholder exists for armv7 architectures, but since they
12 * are commonly available in silicon now, fastmodel usage makes less sense
13 * for them.
14 */
15#include <common.h>
Linus Walleij202a6742015-03-23 11:06:11 +010016#include <command.h>
Darwin Rambo261d2762014-06-09 11:12:59 -070017
18#define SYSOPEN 0x01
19#define SYSCLOSE 0x02
20#define SYSREAD 0x06
21#define SYSFLEN 0x0C
22
23#define MODE_READ 0x0
24#define MODE_READBIN 0x1
25
26/*
27 * Call the handler
28 */
Linus Walleije769f682015-03-23 11:06:10 +010029static noinline long smh_trap(unsigned int sysnum, void *addr)
Darwin Rambo261d2762014-06-09 11:12:59 -070030{
Linus Walleij4e1ef152014-12-15 11:05:56 +010031 register long result asm("r0");
Darwin Rambo261d2762014-06-09 11:12:59 -070032#if defined(CONFIG_ARM64)
33 asm volatile ("hlt #0xf000" : "=r" (result) : "0"(sysnum), "r"(addr));
Vadzim Dambrouski432a6242015-10-19 19:40:14 +030034#elif defined(CONFIG_CPU_V7M)
35 asm volatile ("bkpt #0xAB" : "=r" (result) : "0"(sysnum), "r"(addr));
Darwin Rambo261d2762014-06-09 11:12:59 -070036#else
37 /* Note - untested placeholder */
38 asm volatile ("svc #0x123456" : "=r" (result) : "0"(sysnum), "r"(addr));
39#endif
40 return result;
41}
42
43/*
Linus Walleij9be5c662014-12-15 11:06:05 +010044 * Open a file on the host. Mode is "r" or "rb" currently. Returns a file
45 * descriptor or -1 on error.
46 */
47static long smh_open(const char *fname, char *modestr)
48{
49 long fd;
50 unsigned long mode;
51 struct smh_open_s {
52 const char *fname;
53 unsigned long mode;
54 size_t len;
55 } open;
56
57 debug("%s: file \'%s\', mode \'%s\'\n", __func__, fname, modestr);
58
59 /* Check the file mode */
60 if (!(strcmp(modestr, "r"))) {
61 mode = MODE_READ;
62 } else if (!(strcmp(modestr, "rb"))) {
63 mode = MODE_READBIN;
64 } else {
65 printf("%s: ERROR mode \'%s\' not supported\n", __func__,
66 modestr);
67 return -1;
68 }
69
70 open.fname = fname;
71 open.len = strlen(fname);
72 open.mode = mode;
73
74 /* Open the file on the host */
75 fd = smh_trap(SYSOPEN, &open);
76 if (fd == -1)
77 printf("%s: ERROR fd %ld for file \'%s\'\n", __func__, fd,
78 fname);
79
80 return fd;
81}
82
83/*
84 * Read 'len' bytes of file into 'memp'. Returns 0 on success, else failure
85 */
86static long smh_read(long fd, void *memp, size_t len)
87{
88 long ret;
89 struct smh_read_s {
90 long fd;
91 void *memp;
92 size_t len;
93 } read;
94
Vadzim Dambrouski7bdf75c2015-10-19 19:40:15 +030095 debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
Linus Walleij9be5c662014-12-15 11:06:05 +010096
97 read.fd = fd;
98 read.memp = memp;
99 read.len = len;
100
101 ret = smh_trap(SYSREAD, &read);
102 if (ret < 0) {
103 /*
104 * The ARM handler allows for returning partial lengths,
105 * but in practice this never happens so rather than create
106 * hard to maintain partial read loops and such, just fail
107 * with an error message.
108 */
Vadzim Dambrouski7bdf75c2015-10-19 19:40:15 +0300109 printf("%s: ERROR ret %ld, fd %ld, len %zu memp %p\n",
Linus Walleij9be5c662014-12-15 11:06:05 +0100110 __func__, ret, fd, len, memp);
111 return -1;
112 }
113
114 return 0;
115}
116
117/*
118 * Close the file using the file descriptor
119 */
120static long smh_close(long fd)
121{
122 long ret;
123
124 debug("%s: fd %ld\n", __func__, fd);
125
126 ret = smh_trap(SYSCLOSE, &fd);
127 if (ret == -1)
128 printf("%s: ERROR fd %ld\n", __func__, fd);
129
130 return ret;
131}
132
133/*
134 * Get the file length from the file descriptor
135 */
136static long smh_len_fd(long fd)
137{
138 long ret;
139
140 debug("%s: fd %ld\n", __func__, fd);
141
142 ret = smh_trap(SYSFLEN, &fd);
143 if (ret == -1)
144 printf("%s: ERROR ret %ld, fd %ld\n", __func__, ret, fd);
145
146 return ret;
147}
148
Linus Walleij202a6742015-03-23 11:06:11 +0100149static int smh_load_file(const char * const name, ulong load_addr,
150 ulong *end_addr)
151{
152 long fd;
153 long len;
154 long ret;
155
156 fd = smh_open(name, "rb");
157 if (fd == -1)
158 return -1;
159
160 len = smh_len_fd(fd);
161 if (len < 0) {
162 smh_close(fd);
163 return -1;
164 }
165
166 ret = smh_read(fd, (void *)load_addr, len);
167 smh_close(fd);
168
169 if (ret == 0) {
170 *end_addr = load_addr + len - 1;
171 printf("loaded file %s from %08lX to %08lX, %08lX bytes\n",
172 name,
173 load_addr,
174 *end_addr,
175 len);
176 } else {
177 printf("read failed\n");
178 return 0;
179 }
180
181 return 0;
182}
183
184static int do_smhload(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
185{
186 if (argc == 3 || argc == 4) {
187 ulong load_addr;
188 ulong end_addr = 0;
Ryan Harkin072c8c42017-03-02 17:45:16 +0000189 int ret;
Linus Walleij202a6742015-03-23 11:06:11 +0100190 char end_str[64];
191
192 load_addr = simple_strtoul(argv[2], NULL, 16);
193 if (!load_addr)
194 return -1;
195
196 ret = smh_load_file(argv[1], load_addr, &end_addr);
197 if (ret < 0)
Ryan Harkin072c8c42017-03-02 17:45:16 +0000198 return CMD_RET_FAILURE;
Linus Walleij202a6742015-03-23 11:06:11 +0100199
200 /* Optionally save returned end to the environment */
201 if (argc == 4) {
202 sprintf(end_str, "0x%08lx", end_addr);
Simon Glass382bee52017-08-03 12:22:09 -0600203 env_set(argv[3], end_str);
Linus Walleij202a6742015-03-23 11:06:11 +0100204 }
205 } else {
206 return CMD_RET_USAGE;
207 }
208 return 0;
209}
210
211U_BOOT_CMD(smhload, 4, 0, do_smhload, "load a file using semihosting",
212 "<file> 0x<address> [end var]\n"
213 " - load a semihosted file to the address specified\n"
214 " if the optional [end var] is specified, the end\n"
215 " address of the file will be stored in this environment\n"
216 " variable.\n");