+/*
+ * Copyright 2014 Broadcom Corporation
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * Minimal semihosting implementation for reading files into memory. If more
+ * features like writing files or console output are required they can be
+ * added later. This code has been tested on arm64/aarch64 fastmodel only.
+ * An untested placeholder exists for armv7 architectures, but since they
+ * are commonly available in silicon now, fastmodel usage makes less sense
+ * for them.
+ */
+#include <common.h>
+#include <asm/semihosting.h>
+
+#define SYSOPEN 0x01
+#define SYSCLOSE 0x02
+#define SYSREAD 0x06
+#define SYSFLEN 0x0C
+
+#define MODE_READ 0x0
+#define MODE_READBIN 0x1
+
+/*
+ * Call the handler
+ */
+static int smh_trap(unsigned int sysnum, void *addr)
+{
+ register int result asm("r0");
+#if defined(CONFIG_ARM64)
+ asm volatile ("hlt #0xf000" : "=r" (result) : "0"(sysnum), "r"(addr));
+#else
+ /* Note - untested placeholder */
+ asm volatile ("svc #0x123456" : "=r" (result) : "0"(sysnum), "r"(addr));
+#endif
+ return result;
+}
+
+/*
+ * Open, load a file into memory, and close it. Check that the available space
+ * is sufficient to store the entire file. Return the bytes actually read from
+ * the file as seen by the read function. The verbose flag enables some extra
+ * printing of successful read status.
+ */
+int smh_load(const char *fname, void *memp, int avail, int verbose)
+{
+ int ret, fd, len;
+
+ ret = -1;
+
+ debug("%s: fname \'%s\', avail %u, memp %p\n", __func__, fname,
+ avail, memp);
+
+ /* Open the file */
+ fd = smh_open(fname, "rb");
+ if (fd == -1)
+ return ret;
+
+ /* Get the file length */
+ ret = smh_len_fd(fd);
+ if (ret == -1) {
+ smh_close(fd);
+ return ret;
+ }
+
+ /* Check that the file will fit in the supplied buffer */
+ if (ret > avail) {
+ printf("%s: ERROR ret %d, avail %u\n", __func__, ret,
+ avail);
+ smh_close(fd);
+ return ret;
+ }
+
+ len = ret;
+
+ /* Read the file into the buffer */
+ ret = smh_read(fd, memp, len);
+ if (ret == 0) {
+ /* Print successful load information if requested */
+ if (verbose) {
+ printf("\n%s\n", fname);
+ printf(" 0x%8p dest\n", memp);
+ printf(" 0x%08x size\n", len);
+ printf(" 0x%08x avail\n", avail);
+ }
+ }
+
+ /* Close the file */
+ smh_close(fd);
+
+ return ret;
+}
+
+/*
+ * Read 'len' bytes of file into 'memp'. Returns 0 on success, else failure
+ */
+int smh_read(int fd, void *memp, int len)
+{
+ int ret;
+ struct smh_read_s {
+ int fd;
+ void *memp;
+ int len;
+ } read;
+
+ debug("%s: fd %d, memp %p, len %d\n", __func__, fd, memp, len);
+
+ read.fd = fd;
+ read.memp = memp;
+ read.len = len;
+
+ ret = smh_trap(SYSREAD, &read);
+ if (ret == 0) {
+ return 0;
+ } else {
+ /*
+ * The ARM handler allows for returning partial lengths,
+ * but in practice this never happens so rather than create
+ * hard to maintain partial read loops and such, just fail
+ * with an error message.
+ */
+ printf("%s: ERROR ret %d, fd %d, len %u memp %p\n",
+ __func__, ret, fd, len, memp);
+ }
+ return ret;
+}
+
+/*
+ * Open a file on the host. Mode is "r" or "rb" currently. Returns a file
+ * descriptor or -1 on error.
+ */
+int smh_open(const char *fname, char *modestr)
+{
+ int ret, fd, mode;
+ struct smh_open_s {
+ const char *fname;
+ unsigned int mode;
+ unsigned int len;
+ } open;
+
+ debug("%s: file \'%s\', mode \'%s\'\n", __func__, fname, modestr);
+
+ ret = -1;
+
+ /* Check the file mode */
+ if (!(strcmp(modestr, "r"))) {
+ mode = MODE_READ;
+ } else if (!(strcmp(modestr, "rb"))) {
+ mode = MODE_READBIN;
+ } else {
+ printf("%s: ERROR mode \'%s\' not supported\n", __func__,
+ modestr);
+ return ret;
+ }
+
+ open.fname = fname;
+ open.len = strlen(fname);
+ open.mode = mode;
+
+ /* Open the file on the host */
+ fd = smh_trap(SYSOPEN, &open);
+ if (fd == -1)
+ printf("%s: ERROR fd %d for file \'%s\'\n", __func__, fd,
+ fname);
+
+ return fd;
+}
+
+/*
+ * Close the file using the file descriptor
+ */
+int smh_close(int fd)
+{
+ int ret;
+ long fdlong;
+
+ debug("%s: fd %d\n", __func__, fd);
+
+ fdlong = (long)fd;
+ ret = smh_trap(SYSCLOSE, &fdlong);
+ if (ret == -1)
+ printf("%s: ERROR fd %d\n", __func__, fd);
+
+ return ret;
+}
+
+/*
+ * Get the file length from the file descriptor
+ */
+int smh_len_fd(int fd)
+{
+ int ret;
+ long fdlong;
+
+ debug("%s: fd %d\n", __func__, fd);
+
+ fdlong = (long)fd;
+ ret = smh_trap(SYSFLEN, &fdlong);
+ if (ret == -1)
+ printf("%s: ERROR ret %d\n", __func__, ret);
+
+ return ret;
+}
+
+/*
+ * Get the file length from the filename
+ */
+int smh_len(const char *fname)
+{
+ int ret, fd, len;
+
+ debug("%s: file \'%s\'\n", __func__, fname);
+
+ /* Open the file */
+ fd = smh_open(fname, "rb");
+ if (fd == -1)
+ return fd;
+
+ /* Get the file length */
+ len = smh_len_fd(fd);
+
+ /* Close the file */
+ ret = smh_close(fd);
+ if (ret == -1)
+ return ret;
+
+ debug("%s: returning len %d\n", __func__, len);
+
+ /* Return the file length (or -1 error indication) */
+ return len;
+}
projects / karo-tx-uboot.git / commitdiff