diff --git a/src/helper/Makefile.am b/src/helper/Makefile.am
index 93df6058147ccc47af0e5c2239647cb503b626e1..757eb2e1b4b0ffa5acab6c2aeb122775aeeb7aeb 100644
--- a/src/helper/Makefile.am
+++ b/src/helper/Makefile.am
@@ -23,6 +23,7 @@ libhelper_la_SOURCES = \
time_support.c \
replacements.c \
fileio.c \
+ membuf.c \
startup_tcl.c
if IOUTIL
@@ -41,6 +42,7 @@ noinst_HEADERS = \
types.h \
log.h \
command.h \
+ membuf.h \
time_support.h \
replacements.h \
fileio.h \
diff --git a/src/helper/membuf.c b/src/helper/membuf.c
new file mode 100644
index 0000000000000000000000000000000000000000..af396ca0c7637c7c79951ebea7c7f60a17d92f5e
--- /dev/null
+++ b/src/helper/membuf.c
@@ -0,0 +1,238 @@
+/***************************************************************************
+ * Copyright (C) 2009 By Duane Ellis *
+ * openocd@duaneellis.com *
+ * *
+ * This program 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 2 of the License, or *
+ * (at your option) any later version. *
+ * *
+ * This program 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, write to the *
+ * Free Software Foundation, Inc., *
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
+ ***************************************************************************/
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <malloc.h>
+#include <string.h>
+
+#include "membuf.h"
+
+struct membuf {
+ // buflen is alway "+1" bigger then
+ // what is shown here, the +1 is for
+ // the NULL string terminator
+#define DEFAULT_BUFSIZE 100
+ size_t maxlen; // allocated size
+ size_t curlen; // where we are inserting at
+ char *_strtoklast;
+ void *buf;
+};
+
+
+#define space_avail( pBuf ) (pBuf->maxlen - pBuf->curlen)
+#define dataend( pBuf ) ( ((char *)(pBuf->buf)) + pBuf->curlen )
+
+size_t
+membuf_len( struct membuf *pBuf )
+{
+ return pBuf->curlen;
+}
+
+const void *
+membuf_datapointer( struct membuf *pBuf )
+{
+ return ((void *)(pBuf->buf));
+}
+
+const char *
+membuf_strtok( struct membuf *pBuf, const char *sep, void **pLast )
+{
+ if( pBuf ){
+ pBuf->_strtoklast = NULL;
+ *pLast = pBuf;
+ return strtok_r( ((char *)(pBuf->buf)), sep, &(pBuf->_strtoklast) );
+ } else {
+ // recover our pBuf
+ pBuf = *((struct membuf **)(pLast));
+ return strtok_r( NULL, sep, &(pBuf->_strtoklast) );
+ }
+}
+
+
+
+struct membuf *
+membuf_new(void)
+{
+ // by default - parameters are zero.
+ struct membuf *pBuf;
+
+ pBuf = calloc( 1, sizeof(*pBuf) );
+ if( pBuf ){
+ // we *ALWAYS* allocate +1 for null terminator.
+ pBuf->buf = calloc( DEFAULT_BUFSIZE+1, sizeof(char));
+ if( pBuf->buf == NULL ){
+ free(pBuf);
+ pBuf = NULL;
+ } else {
+ pBuf->maxlen = DEFAULT_BUFSIZE;
+ }
+ }
+ return pBuf;
+}
+
+
+struct membuf *
+membuf_grow( struct membuf *pBuf, int n )
+{
+ void *vp;
+ signed int newsize;
+
+ // this is a *SIGNED* value
+ newsize = ((int)(pBuf->maxlen)) + n;
+
+ // do not go negative, or too small
+ if( newsize < DEFAULT_BUFSIZE ){
+ newsize = DEFAULT_BUFSIZE;
+ }
+
+ // always alloc +1 for the null terminator
+ vp = realloc( pBuf->buf, newsize+1 );
+ if( vp ){
+ pBuf->buf = vp;
+ pBuf->maxlen = newsize;
+ return pBuf;
+ } else {
+ return NULL;
+ }
+}
+
+
+void membuf_reset( struct membuf *pBuf )
+{
+ pBuf->curlen = 0;
+}
+
+
+void membuf_delete( struct membuf *pBuf )
+{
+ if( pBuf ){
+ if( pBuf->buf){
+ // wack data so it cannot be reused
+ memset(pBuf->buf,0,pBuf->maxlen);
+ free(pBuf->buf);
+ }
+ // wack dat so it cannot be reused
+ memset(pBuf,0,sizeof(pBuf));
+ free(pBuf);
+ }
+}
+
+int
+membuf_sprintf( struct membuf *pBuf , const char *fmt, ... )
+{
+ int r;
+ va_list ap;
+ va_start( ap, fmt );
+ r = membuf_vsprintf( pBuf, fmt, ap );
+ va_end(ap);
+ return r;
+}
+
+int
+membuf_vsprintf( struct membuf *pBuf, const char *fmt, va_list ap )
+{
+ int r;
+ size_t sa;
+ int grew;
+
+
+ grew = 0;
+ for(;;) {
+ sa = space_avail(pBuf);
+
+ // do work
+ r = vsnprintf( dataend( pBuf ),
+ sa,
+ fmt,
+ ap );
+ if( (r > 0) && (((size_t)(r)) < sa) ){
+ // Success!
+ pBuf->curlen += ((size_t)(r));
+ // remember: We always alloc'ed +1
+ // so this does not overflow
+ ((char *)(pBuf->buf))[ pBuf->curlen ] = 0;
+ r = 0;
+ break;
+ }
+
+ // failure
+ if( r < 0 ){
+ // Option(A) format error
+ // Option(B) glibc2.0 bug
+ // assume (B).
+ r = (4 * DEFAULT_BUFSIZE);
+ }
+
+ // don't do this again
+ if( grew ){
+ r = -1;
+ break;
+ }
+ grew = 1;
+ pBuf = membuf_grow( pBuf, r );
+ if(pBuf == NULL){
+ // grow failed
+ r = -1;
+ break;
+ }
+ }
+ return r;
+}
+
+struct membuf *
+membuf_strcat( struct membuf *pBuf, const char *pStr )
+{
+ return membuf_append( pBuf, pStr, strlen( pStr ) );
+}
+
+struct membuf *
+membuf_append( struct membuf *pBuf, const void *pData, size_t len )
+{
+ size_t sa;
+ int r;
+
+ // how much room is there?
+ sa = space_avail( pBuf );
+
+ // will it fit?
+ if( sa < len ){
+ // if not, how much do we need?
+ r = ((int)(sa - len));
+ // do the grow.
+ pBuf = membuf_grow( pBuf, r );
+ // failed?
+ if(pBuf==NULL){
+ return pBuf;
+ }
+ }
+ // append
+ memcpy( dataend(pBuf),
+ pData,
+ len );
+ pBuf->curlen += len;
+ return pBuf;
+}
+
+
+
+
+
+
diff --git a/src/helper/membuf.h b/src/helper/membuf.h
new file mode 100644
index 0000000000000000000000000000000000000000..6b291ff212cb1754c5bafd29475481aa8f9652d0
--- /dev/null
+++ b/src/helper/membuf.h
@@ -0,0 +1,118 @@
+#ifndef HELPER_MEMBUF_H
+#define HELPER_MEMBUF_H
+
+/** @file */
+
+/** @page MEMBUF - an auto-growing string buffer
+ *
+ * With OpenOCD often, one must write code that sends text to
+ * different places.. the historical command_ctx, or JIM output,
+ * and/or other places.
+ *
+ * This is a simple 'string buffer' that auto-grows.
+ *
+ * More correctly put, this is a "memory buffer"
+ * it may contain binary data
+ *
+ * Note: Internally the buffer always has a 'null terminator'
+ */
+
+/* contents of this structure are 'opaque' */
+struct membuf;
+
+
+/** Create a new membuf
+ * By default the memory buffer has "some non-zero-size"
+ * (couple hundred bytes, exact amount is opaque)
+ */
+struct membuf *membuf_new(void);
+
+/** delete (destroy) the mem buffer
+ * @param pBuf - buffer to release
+ */
+void membuf_delete( struct membuf *pBuf );
+
+
+/** grow/shrink a membuf by specified amount.
+ * @param pBuf - the buffer
+ * @param amount - the amount to grow or shrink by.
+ *
+ * Symantics of 'realloc()' return NULL on failure
+ */
+struct membuf *membuf_grow( struct membuf *pBuf, int amount );
+
+/** how long is this buffer (memlen(), strlen())
+ * @param pBuf - the buffer
+ *
+ * @returns: length of current buffer.
+ */
+size_t membuf_len( struct membuf *pBuf );
+
+
+/** reset an membuf to zero length.
+ * @param pBuf - buffer to reset
+ *
+ * Note this does not 'release' the memory buffer
+ */
+void membuf_reset( struct membuf *pBuf );
+
+
+/** sprintf() to the string buffer
+ * @param pBuf - buffer to capture sprintf() data into
+ * @param fmt - printf format
+ *
+ * Returns 0 on success
+ * Returns non-zero on failure
+ */
+int membuf_sprintf( struct membuf *pBuf , const char *fmt, ... );
+
+/** vsprintf() to the string buffer
+ * @param pBuf - buffer to capture sprintf() data into
+ * @param fmt - printf format
+ * @param ap - va_list for fmt
+ *
+ * Returns 0 on success
+ * Returns non-zero on failure
+ */
+int membuf_vsprintf( struct membuf *pBuf , const char *fmt, va_list ap);
+
+/** Tokenize lines using strtok()
+ * @param pBuf - buffer to tokenize
+ * @param delim - delimiter parameter for strtok_r()
+ *
+ * Identical to "strtok()" - pass "pBuff=NULL" on second call
+ *
+ * NOTE: This call is <b>destructive</b> to the buffer.
+ */
+const char *membuf_strtok( struct membuf *pBuf, const char *delim, void **pSave );
+
+/** Return pointer to the memory in the buffer
+ * @param pBuf - buffer
+ *
+ * NOTE: Thou shall not modify this pointer, it is <b>CONST</b>
+ */
+const void *membuf_datapointer( struct membuf *pBuf );
+
+
+/** Append data to the buffer
+ * @param pBuf - buffer to append
+ * @param pData - pointer to data to append
+ * @param len - length of data to append
+ *
+ * Modified symantics of "memcpy()". On memory allocation failure
+ * returns NULL. On success, returns pointer to orginal membuf.
+ */
+struct membuf *membuf_append( struct membuf *pBuf, const void *pData, size_t len );
+
+
+/** Append string to the buffer
+ * @param pBuf - buffer to append
+ * @param str - string to append
+ *
+ * Modified symantics of "strcat()". On memory allocation failure
+ * returns NULL. On success, returns pointer to orginal membuf.
+ */
+struct membuf *membuf_strcat( struct membuf *pBuf, const char *s );
+
+
+#endif