1 files changed, 95 insertions, 0 deletions
diff --git a/os/various/memstreams.c b/os/various/memstreams.c
new file mode 100644
index 000000000..935847ece
--- /dev/null
+++ b/os/various/memstreams.c
@@ -0,0 +1,95 @@
+/*
+    ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
+
+    This file is part of ChibiOS/RT.
+
+    ChibiOS/RT is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    ChibiOS/RT is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file    memstreams.c
+ * @brief   Memory streams code.
+ *
+ * @addtogroup memory_streams
+ * @{
+ */
+
+#include <string.h>
+
+#include "ch.h"
+#include "memstreams.h"
+
+/*
+ * @brief   Write virtual method implementation.
+ *
+ * @param[in] ip        pointer to a @p MemoryStream object
+ * @param[in] bp        pointer to the data buffer
+ * @param[in] n         the maximum amount of data to be transferred
+ * @return              The number of bytes transferred. The return value can
+ *                      be less than the specified number of bytes if the
+ *                      stream reaches a physical end of file and cannot be
+ *                      extended.
+ */
+static size_t writes(void *ip, const uint8_t *bp, size_t n) {
+  MemoryStream *msp = ip;
+
+  if (msp->size - msp->eos < n)
+    n = msp->size - msp->eos;
+  memcpy(msp->buffer + msp->eos, bp, n);
+  msp->eos += n;
+  return n;
+}
+
+/*
+ * @brief   Read virtual method implementation.
+ *
+ * @param[in] ip        pointer to a @p MemoryStream object
+ * @param[out] bp       pointer to the data buffer
+ * @param[in] n         the maximum amount of data to be transferred
+ * @return              The number of bytes transferred. The return value can
+ *                      be less than the specified number of bytes if the
+ *                      stream reaches the end of the available data.
+ */
+static size_t reads(void *ip, uint8_t *bp, size_t n) {
+  MemoryStream *msp = ip;
+
+  if (msp->eos - msp->offset < n)
+    n = msp->eos - msp->offset;
+  memcpy(bp, msp->buffer + msp->offset, n);
+  msp->offset += n;
+  return n;
+}
+
+static const struct MemStreamVMT vmt = {writes, reads};
+
+/**
+ * @brief   Memory stream object initialization.
+ *
+ * @param[out] msp      pointer to the @p MemoryStream object to be initialized
+ * @param[in] buffer    pointer to the memory buffer for the memory stream
+ * @param[in] size      total size of the memory stream buffer
+ * @param[in] eos       initial End Of Stream offset. Normally you need to
+ *                      put this to zero for RAM buffers or equal to @p size
+ *                      for ROM streams.
+ */
+void msObjectInit(MemoryStream *msp, uint8_t *buffer, size_t size, size_t eos) {
+
+  msp->vmt    = &vmt;
+  msp->buffer = buffer;
+  msp->size   = size;
+  msp->eos    = eos;
+  msp->offset = 0;
+}
+
+/** @} */