Added semihosting support.

2 files changed, 196 insertions, 0 deletions

diff --git a/os/include/semifs.h b/os/include/semifs.h
new file mode 100644
index 0000000..01bc700
--- /dev/null
+++ b/os/include/semifs.h
@@ -0,0 +1,6 @@
+#ifndef __SEMIFS_H__
+#define __SEMIFS_H__
+
+void register_semifs();
+
+#endif
diff --git a/os/src/semifs.c b/os/src/semifs.c
new file mode 100644
index 0000000..fc7d0b1
--- /dev/null
+++ b/os/src/semifs.c
@@ -0,0 +1,190 @@
+/* Copyright (c) 2010 James Snyder, eLua Project.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the right
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <stdint.h>
+#include <fcntl.h>
+
+#include <angel.h>
+
+#include "filesystem.h"
+#include "fio.h"
+#include "semifs.h"
+#include "osdebug.h"
+
+struct semifs_fds_t {
+    uint32_t file;
+    uint32_t cursor;
+};
+
+static struct semifs_fds_t semifs_fds[MAX_FDS];
+
+// These structures provided by Simon Ford of mbed
+struct semifs_FTime {
+    uint8_t  hr;                        // Hours    [0..23]
+    uint8_t  min;                       // Minutes  [0..59]
+    uint8_t  sec;                       // Seconds  [0..59]
+    uint8_t  day;                       // Day      [1..31]
+    uint8_t  mon;                       // Month    [1..12]
+    uint16_t year;                      // Year     [1980..2107]
+};
+
+// File Search info record
+struct semifs_XF_Info {
+    char name[32];                      // File - 32-bytes
+    uint32_t size;                      // File size in bytes - 4-bytes
+    uint16_t fileID;                    // System File Identification  - 2-bytes
+    struct semifs_FTime create_time;    // Date & time file was created
+    struct semifs_FTime write_time;     // Date & time of last write
+};
+
+struct semifs_SearchInfo {
+    const char *pattern;
+    struct semifs_XF_Info file_info;
+};
+
+/*****************************************************************************/
+
+static int semifs_close(void * opaque) {
+    struct semifs_fds_t * f = (struct semifs_fds_t *) opaque;
+//    DBGOUT("semifs_close(%p)\r\n", opaque);
+    
+    return Semihost_SYS_CLOSE(&f->file);
+}
+
+static ssize_t semifs_write(void * opaque, const void * ptr, size_t len) {
+    struct semifs_fds_t * f = (struct semifs_fds_t *) opaque;
+//    DBGOUT("semifs_write(%p, %p, %i)\r\n", opaque, ptr, len);
+
+    uint32_t args[3];
+    args[0] = (uint32_t) f->file;
+    args[1] = (uint32_t) ptr;
+    args[2] = (uint32_t) len;
+
+    // Perform write
+    int res = Semihost_SYS_WRITE(args);
+//    DBGOUT("semifs_read: Semihost_SYS_WRITE returned %i\r\n", res);
+    if (res == -1 || res == len)
+        return -1;
+
+    // Update position
+    f->cursor += len - res;
+    return len - res;
+}
+
+static ssize_t semifs_read(void * opaque, void * ptr, size_t len) {
+    struct semifs_fds_t * f = (struct semifs_fds_t *) opaque;
+//    DBGOUT("semifs_read(%p, %p, %i)\r\n", opaque, ptr, len);
+
+    uint32_t args[3];
+    args[0] = (uint32_t) f->file;
+    args[1] = (uint32_t) ptr;
+    args[2] = (uint32_t) len;
+
+    // Perform read
+    int res = Semihost_SYS_READ(args);
+    DBGOUT("semifs_read: Semihost_SYS_READ returned %i\r\n", res);
+    if (res < 0)
+        return -1;
+
+    // Update position
+    f->cursor += len - res;
+    return len - res;
+}
+
+static off_t semifs_seek(void * opaque, off_t off, int whence) {
+    uint32_t args[2], len;
+    struct semifs_fds_t * f = (struct semifs_fds_t *) opaque;
+//    DBGOUT("semifs_seek(%p, %i, %i)\r\n", opaque, off, whence);
+
+    switch (whence) {
+    case SEEK_CUR:
+        // seek from current position
+        off += f->cursor;
+        whence = SEEK_SET;
+        break;
+
+    case SEEK_END:
+        // seek from end of file
+        args[0] = (uint32_t) f->file;
+        len = Semihost_SYS_FLEN(args);
+//        DBGOUT("semifs_seek: Semihost_SYS_FLEN returned %i\r\n", len);
+        off += len;
+        break;
+    }
+    // Do absolute seek
+    args[0] = (uint32_t) f->file;
+    args[1] = (uint32_t) off;
+    int res = Semihost_SYS_SEEK(args);
+//    DBGOUT("semifs_seek: Semihost_SYS_SEEK returned %i\r\n", res);
+
+    if (res == 0)
+        f->cursor = off;
+
+    /* This is expected to return the position in the file.  */
+    return res == 0 ? off : -1;
+}
+
+static int semifs_open(void * opaque, const char *path, int flags, int mode) {
+    int aflags = 0;
+    unsigned int fh;
+    uint32_t args[3];
+//    DBGOUT("semifs_open(%p, \"%s\", %i, %i)\r\n");
+
+    if (flags & O_RDWR)
+        aflags |= 2;
+
+    if (flags & O_CREAT)
+        aflags |= 4;
+
+    if (flags & O_TRUNC)
+        aflags |= 4;
+
+    if (flags & O_APPEND) {
+        aflags &= ~4; // Can't ask for w AND a; means just 'a'.
+        aflags |= 8;
+    }
+
+    // Find file and open it (via semihosting call)
+    args[0] = (uint32_t) path;
+    args[1] = (uint32_t) aflags;
+    args[2] = (uint32_t) strlen(path);
+    fh = Semihost_SYS_OPEN(args);
+//    DBGOUT("Semihost_SYS_OPEN returns: %i\r\n", fh);
+
+    if (fh >= 0) {
+        int fd = fio_open(semifs_read, semifs_write, semifs_seek, semifs_close, (void *) fh);
+//        DBGOUT("semifs_open: fio_open returned %i\r\n", fd);
+        if (fd < 0)
+            Semihost_SYS_CLOSE((uint32_t *) &fd);
+        semifs_fds[fd].file = fh;
+        semifs_fds[fd].cursor = 0;
+        fio_set_opaque(fd, semifs_fds + fd);
+        return fd;
+    }
+    return -1;
+}
+
+void register_semifs() {
+    DBGOUT("Registering semihost fs\r\n");
+    register_fs("host", semifs_open, NULL);
+}