1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2014 Broadcom Corporation
7 * Minimal semihosting implementation for reading files into memory. If more
8 * features like writing files or console output are required they can be
9 * added later. This code has been tested on arm64/aarch64 fastmodel only.
10 * An untested placeholder exists for armv7 architectures, but since they
11 * are commonly available in silicon now, fastmodel usage makes less sense
23 #define MODE_READBIN 0x1
28 static noinline long smh_trap(unsigned int sysnum, void *addr)
30 register long result asm("r0");
31 #if defined(CONFIG_ARM64)
32 asm volatile ("hlt #0xf000" : "=r" (result) : "0"(sysnum), "r"(addr));
33 #elif defined(CONFIG_CPU_V7M)
34 asm volatile ("bkpt #0xAB" : "=r" (result) : "0"(sysnum), "r"(addr));
36 /* Note - untested placeholder */
37 asm volatile ("svc #0x123456" : "=r" (result) : "0"(sysnum), "r"(addr));
43 * Open a file on the host. Mode is "r" or "rb" currently. Returns a file
44 * descriptor or -1 on error.
46 static long smh_open(const char *fname, char *modestr)
56 debug("%s: file \'%s\', mode \'%s\'\n", __func__, fname, modestr);
58 /* Check the file mode */
59 if (!(strcmp(modestr, "r"))) {
61 } else if (!(strcmp(modestr, "rb"))) {
64 printf("%s: ERROR mode \'%s\' not supported\n", __func__,
70 open.len = strlen(fname);
73 /* Open the file on the host */
74 fd = smh_trap(SYSOPEN, &open);
76 printf("%s: ERROR fd %ld for file \'%s\'\n", __func__, fd,
83 * Read 'len' bytes of file into 'memp'. Returns 0 on success, else failure
85 static long smh_read(long fd, void *memp, size_t len)
94 debug("%s: fd %ld, memp %p, len %zu\n", __func__, fd, memp, len);
100 ret = smh_trap(SYSREAD, &read);
103 * The ARM handler allows for returning partial lengths,
104 * but in practice this never happens so rather than create
105 * hard to maintain partial read loops and such, just fail
106 * with an error message.
108 printf("%s: ERROR ret %ld, fd %ld, len %zu memp %p\n",
109 __func__, ret, fd, len, memp);
117 * Close the file using the file descriptor
119 static long smh_close(long fd)
123 debug("%s: fd %ld\n", __func__, fd);
125 ret = smh_trap(SYSCLOSE, &fd);
127 printf("%s: ERROR fd %ld\n", __func__, fd);
133 * Get the file length from the file descriptor
135 static long smh_len_fd(long fd)
139 debug("%s: fd %ld\n", __func__, fd);
141 ret = smh_trap(SYSFLEN, &fd);
143 printf("%s: ERROR ret %ld, fd %ld\n", __func__, ret, fd);
148 static int smh_load_file(const char * const name, ulong load_addr,
155 fd = smh_open(name, "rb");
159 len = smh_len_fd(fd);
165 ret = smh_read(fd, (void *)load_addr, len);
169 *end_addr = load_addr + len - 1;
170 printf("loaded file %s from %08lX to %08lX, %08lX bytes\n",
176 printf("read failed\n");
183 static int do_smhload(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
185 if (argc == 3 || argc == 4) {
191 load_addr = simple_strtoul(argv[2], NULL, 16);
195 ret = smh_load_file(argv[1], load_addr, &end_addr);
197 return CMD_RET_FAILURE;
199 /* Optionally save returned end to the environment */
201 sprintf(end_str, "0x%08lx", end_addr);
202 env_set(argv[3], end_str);
205 return CMD_RET_USAGE;
210 U_BOOT_CMD(smhload, 4, 0, do_smhload, "load a file using semihosting",
211 "<file> 0x<address> [end var]\n"
212 " - load a semihosted file to the address specified\n"
213 " if the optional [end var] is specified, the end\n"
214 " address of the file will be stored in this environment\n"