1 files changed, 289 insertions, 0 deletions
diff --git a/nuttx/graphics/nxconsole/nxcon_vt100.c b/nuttx/graphics/nxconsole/nxcon_vt100.c
new file mode 100644
index 000000000..3e3374dce
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+++ b/nuttx/graphics/nxconsole/nxcon_vt100.c
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+/****************************************************************************
+ * nuttx/graphics/nxconsole/nxcon_vt100.c
+ *
+ *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <string.h>
+#include <assert.h>
+
+#include <nuttx/vt100.h>
+
+#include "nxcon_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+typedef int (*seqhandler_t)(FAR struct nxcon_state_s *priv);
+
+struct vt100_sequence_s
+{
+  FAR const char *seq;
+  seqhandler_t handler;
+  uint8_t size;
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int nxcon_erasetoeol(FAR struct nxcon_state_s *priv);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/* All recognized VT100 escape sequences.  Very little as present, this is
+ * a placeholder for a future, more complete VT100 emulation.
+ */
+
+/* <esc>[K is the VT100 command erases to the end of the line. */
+
+static const char g_erasetoeol[] = VT100_CLEAREOL;
+
+/* The list of all VT100 sequences supported by the emulation */
+
+static const struct vt100_sequence_s g_vt100sequences[] =
+{
+  {g_erasetoeol, nxcon_erasetoeol, sizeof(g_erasetoeol)},
+  {NULL, NULL, 0}
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxcon_erasetoeol
+ *
+ * Description:
+ *   Handle the erase-to-eol VT100 escapte sequence
+ *
+ * Input Parameters:
+ *   priv - Driver data structure
+ *
+ * Returned Value:
+ *   The index of the match in g_vt100sequences[]
+ *
+ ****************************************************************************/
+
+static int nxcon_erasetoeol(FAR struct nxcon_state_s *priv)
+{
+  /* Does nothing yet (other than consume the sequence) */
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxcon_vt100part
+ *
+ * Description:
+ *   Return the next entry that is a partial match to the sequence.
+ *
+ * Input Parameters:
+ *   priv - Driver data structure
+ *   seqsize - The number of bytes in the sequence
+ *   startndx - The index to start searching
+ *
+ * Returned Value:
+ *   A pointer to the matching sequence in g_vt100sequences[]
+ *
+ ****************************************************************************/
+
+FAR const struct vt100_sequence_s *
+nxcon_vt100part(FAR struct nxcon_state_s *priv, int seqsize)
+{
+  FAR const struct vt100_sequence_s *seq;
+  int ndx;
+
+  /* Search from the beginning of the sequence table */
+
+  for (ndx = 0; g_vt100sequences[ndx].seq; ndx++)
+    {
+      /* Is this sequence big enough? */
+
+      seq = &g_vt100sequences[ndx];
+      if (seq->size >= seqsize)
+        {
+          /* Yes... are the first 'seqsize' bytes the same */
+
+          if (memcmp(seq->seq, priv->seq, seqsize) == 0)
+            {
+              /* Yes.. return the match */
+
+              return seq;
+            }
+        }
+    }
+  return NULL;
+}
+
+/****************************************************************************
+ * Name: nxcon_vt100seq
+ *
+ * Description:
+ *   Determine if the new sequence is a part of a supported VT100 escape
+ *   sequence.
+ *
+ * Input Parameters:
+ *   priv - Driver data structure
+ *   seqsize - The number of bytes in the sequence
+ *
+ * Returned Value:
+ *   state - See enum nxcon_vt100state_e;
+ *
+ ****************************************************************************/
+
+static enum nxcon_vt100state_e nxcon_vt100seq(FAR struct nxcon_state_s *priv,
+                                              int seqsize)
+{
+  FAR const struct vt100_sequence_s *seq;
+  enum nxcon_vt100state_e ret;
+
+  /* Is there any VT100 escape sequence that matches what we have
+   * buffered so far?
+   */
+
+  seq = nxcon_vt100part(priv, seqsize);
+  if (seq)
+    {
+      /* Yes.. if the size of that escape sequence is the same as what we
+       * have buffered, then we have an exact match.
+       */
+
+      if (seq->size == seqsize)
+        {
+          /* Process the VT100 sequence */
+
+          seq->handler(priv);
+          priv->nseq = 0;
+          return VT100_PROCESSED;
+        }
+
+      /* The 'seqsize' is still smaller than the potential match(es).  We
+       * will need to collect more characters before we can make a decision.
+       * Retun an indication that we have consumed the character.
+       */
+
+      return VT100_CONSUMED;
+    }
+
+  /* We get here on a failure.  The buffer sequence is not part of any
+   * supported VT100 escape sequence.  If seqsize > 1 then we need to
+   * return a special value because we have to re-process the buffered
+   * data.
+   */
+
+  ret = seqsize > 1 ? VT100_ABORT : VT100_NOT_CONSUMED;
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxcon_vt100
+ *
+ * Description:
+ *   Test if the newly received byte is part of a VT100 escape sequence
+ *
+ * Input Parameters:
+ *   priv - Driver data structure
+ *   ch - The newly received character
+ *
+ * Returned Value:
+ *   state - See enum nxcon_vt100state_e;
+ *
+ ****************************************************************************/
+
+enum nxcon_vt100state_e nxcon_vt100(FAR struct nxcon_state_s *priv, char ch)
+{
+  enum nxcon_vt100state_e ret;
+  int seqsize;
+
+  DEBUGASSERT(priv && priv->nseq < VT100_MAX_SEQUENCE);
+
+  /* If we have no buffered characters, then 'ch' must be the first character
+   * of an escape sequence.
+   */
+
+  if (priv->nseq < 1)
+    {
+      /* The first character of an escape sequence must be an an escape
+       * character (duh).
+       */
+
+      if (ch != ASCII_ESC)
+        {
+          return VT100_NOT_CONSUMED;
+        }
+
+      /* Add the escape character to the buffer but don't bother with any
+       * further checking.
+       */
+
+      priv->seq[0] = ASCII_ESC;
+      priv->nseq   = 1;
+      return VT100_CONSUMED;
+    }
+
+  /* Temporarily add the next character to the buffer */
+
+  seqsize = priv->nseq;
+  priv->seq[seqsize] = ch;
+
+  /* Then check if this sequence is part of an a valid escape sequence */
+
+  seqsize++;
+  ret = nxcon_vt100seq(priv, seqsize);
+  if (ret == VT100_CONSUMED)
+    {
+      /* The newly added character is indeed part of a VT100 escape sequence
+       * (which is still incomplete).  Keep it in the buffer.
+       */
+
+      priv->nseq = seqsize;
+    }
+  return ret;
+}