diff --git a/trunk/3rdparty/st-srs/md.h b/trunk/3rdparty/st-srs/md.h
index d3158db3fc..416b5b954d 100644
--- a/trunk/3rdparty/st-srs/md.h
+++ b/trunk/3rdparty/st-srs/md.h
@@ -181,15 +181,17 @@ extern void _st_md_cxt_restore(_st_jmp_buf_t env, int val);
 
     #if defined(__amd64__) || defined(__x86_64__)
         #define MD_GET_SP(_t) *((long *)&((_t)->context[0].__jmpbuf[6]))
+        #define MD_GET_BP(_t) *((long *)&((_t)->context[0].__jmpbuf[1]))
     #else
         #error Unknown CPU architecture
     #endif
 
-    #define MD_INIT_CONTEXT(_thread, _sp, _main) \
+    #define MD_INIT_CONTEXT(_thread, _sp, _bp, _main) \
         ST_BEGIN_MACRO                             \
         if (MD_SETJMP((_thread)->context))         \
             _main();                                 \
         MD_GET_SP(_thread) = (long) (_sp);         \
+        MD_GET_BP(_thread) = (long) (_bp);         \
         ST_END_MACRO
 
     #define MD_GET_UTIME()            \
diff --git a/trunk/3rdparty/st-srs/sched.c b/trunk/3rdparty/st-srs/sched.c
index 176e9d1a10..0614377154 100644
--- a/trunk/3rdparty/st-srs/sched.c
+++ b/trunk/3rdparty/st-srs/sched.c
@@ -633,7 +633,16 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinabl
     _st_stack_t *stack;
     void **ptds;
     char *sp;
-    
+
+    void *stack_bp;             /* Frame pointer for this function */
+    void *stack_pbp;            /* Frame pointer for parent function */
+    unsigned long crbp;         /* Current RBP register value */
+    unsigned long crsp;         /* Current RSP register value */
+    unsigned long prbp;         /* Parent RBP register value */
+    int home_space_size;
+    asm volatile("mov %%rbp, %0" : "=r"(crbp));
+    asm volatile("mov %%rsp, %0" : "=r"(crsp));
+
     /* Adjust stack size */
     if (stk_size == 0)
         stk_size = ST_DEFAULT_STACK_SIZE;
@@ -663,7 +672,30 @@ _st_thread_t *st_thread_create(void *(*start)(void *arg), void *arg, int joinabl
     thread->start = start;
     thread->arg = arg;
 
-    _ST_INIT_CONTEXT(thread, stack->sp, _st_thread_main);
+    /* Initialize RBP and return address for parent coroutine. */
+    prbp = *(unsigned long*)crbp;
+    stack->sp = (char*)stack->sp - 0x10; /* For ra and rbp. */
+    *(((unsigned long*)stack->sp) + 1) = *(((unsigned long*)prbp) + 1); /* Save parent RA(return address) */
+    *(unsigned long*)stack->sp = *(unsigned long*)prbp; /* Save parent RBP */
+
+    stack_pbp = stack->sp;
+    home_space_size = (int)(prbp - crbp - 0x10);
+    stack->sp = (char*)stack->sp - home_space_size; /* Save parent home space */
+    memcpy(stack_pbp - home_space_size, (void*)(prbp - home_space_size), home_space_size);
+
+    /* Initialize RBP and return address for new coroutine. */
+    stack->sp = (char*)stack->sp - 0x10; /* For ra and rbp. */
+    *(((unsigned long*)stack->sp) + 1) = *(((unsigned long*)crbp)+1); /* Simulate instruction call, store RA(return address) */
+    *(unsigned long*)stack->sp = *(unsigned long*)crbp; /* Save RBP: push rbp */
+    *(unsigned long*)stack->sp = (unsigned long)stack_pbp; /* Overwrite parent RBP */
+
+    stack_bp = stack->sp; /* Save RSP as RBP: mov rbp, rsp */
+    home_space_size = (int)(crbp - crsp);
+    stack->sp = (char*)stack->sp - home_space_size; /* For home space: sub rsp, 0x20 */
+    memcpy(stack_bp - home_space_size, (void*)(crbp - home_space_size), home_space_size);
+
+    /* Initialize thread context. */
+    _ST_INIT_CONTEXT(thread, stack->sp, stack_bp, _st_thread_main);
 
     /* If thread is joinable, allocate a termination condition variable */
     if (joinable) {
diff --git a/trunk/auto/depends.sh b/trunk/auto/depends.sh
index 38d09bf835..a99616ca3b 100755
--- a/trunk/auto/depends.sh
+++ b/trunk/auto/depends.sh
@@ -323,7 +323,7 @@ cp -rf $SRS_WORKDIR/research/players ${SRS_OBJS}/nginx/html/ &&
 
 # for favicon.ico
 rm -rf ${SRS_OBJS}/nginx/html/favicon.ico &&
-cp -f $SRS_WORKDIR/research/api-server/static-dir/favicon.ico ${SRS_OBJS}/nginx/html/favicon.ico &&
+cp -f $SRS_WORKDIR/research/favicon.ico ${SRS_OBJS}/nginx/html/favicon.ico &&
 
 # For srs-console.
 rm -rf ${SRS_OBJS}/nginx/html/console &&
@@ -335,7 +335,7 @@ cp -rf $SRS_WORKDIR/3rdparty/signaling/www/demos ${SRS_OBJS}/nginx/html/ &&
 
 # For home page index.html
 rm -rf ${SRS_OBJS}/nginx/html/index.html &&
-cp -f $SRS_WORKDIR/research/api-server/static-dir/index.html ${SRS_OBJS}/nginx/html/index.html &&
+cp -f $SRS_WORKDIR/research/index.html ${SRS_OBJS}/nginx/html/index.html &&
 
 # nginx.html to detect whether nginx is alive
 echo "Nginx is ok." > ${SRS_OBJS}/nginx/html/nginx.html
diff --git a/trunk/research/st/backtrace.cpp b/trunk/research/st/backtrace.cpp
new file mode 100644
index 0000000000..71652e9b0b
--- /dev/null
+++ b/trunk/research/st/backtrace.cpp
@@ -0,0 +1,29 @@
+/*
+g++ backtrace.cpp ../../objs/st/libst.a -g -O0 -o backtrace && ./backtrace
+*/
+#include <stdio.h>
+#include "../../objs/st/st.h"
+
+void* pfn(void* arg) {
+    for (;;) {
+        printf("Hello, coroutine\n");
+        st_sleep(1);
+    }
+    return NULL;
+}
+
+int bar(int argc) {
+    st_thread_create(pfn, NULL, 0, 0);
+    return argc + 1;
+}
+
+int foo(int argc) {
+    return bar(argc);
+}
+
+int main(int argc, char** argv) {
+    st_init();
+    foo(argc);
+    st_thread_exit(NULL);
+    return 0;
+}
\ No newline at end of file