From b7b31114717d7737edab9a45419135eff2382488 Mon Sep 17 00:00:00 2001
From: Stu Grossman <grossman@cygnus>
Date: Thu, 4 Jul 1996 00:51:22 +0000
Subject: 	* erc32.c (mec_reset mec_read mec_write memory_read
 memory_write), 	sis.h:  Get rid of all uses of long long's. 	*
 (close_port read_uart write_uart uarta_tx):  Don't seg fault 	when can't
 open pty's. 	* exec.c:  Add two new instructions: smul, and divscc. 	*
 interf.c (flush_windows):  New routine to flush the register 	windows out to
 the stack just before returning to GDB.  Makes 	backtraces work much
 better.

---
 sim/erc32/interf.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

(limited to 'sim/erc32/interf.c')

diff --git a/sim/erc32/interf.c b/sim/erc32/interf.c
index e81fbf3..2cc3a00 100644
--- a/sim/erc32/interf.c
+++ b/sim/erc32/interf.c
@@ -228,10 +228,12 @@ sim_close(int quitting)
 
 };
 
+/* Return non-zero if the caller should handle the load. Zero if
+     we have loaded the image. */
 int
 sim_load(char *prog, int from_tty)
 {
-    bfd_load(*prog);
+    bfd_load(prog);
     return (0);
 }
 
@@ -317,11 +319,63 @@ sim_stop_reason(enum sim_stop * reason, int *sigrc)
     simstat = OK;
 }
 
+/* Flush all register windows out to the stack.  Starting after the invalid
+   window, flush all windows up to, and including the current window.  This
+   allows GDB to do backtraces and look at local variables for frames that
+   are still in the register windows.  Note that strictly speaking, this
+   behavior is *wrong* for several reasons.  First, it doesn't use the window
+   overflow handlers.  It therefore assumes standard frame layouts and window
+   handling policies.  Second, it changes system state behind the back of the
+   target program.  I expect this to mainly pose problems when debugging trap
+   handlers.
+*/
+
+#define PSR_CWP 0x7
+
+static void
+flush_windows ()
+{
+  int invwin;
+  int cwp;
+  int win;
+  int ws;
+
+  /* Keep current window handy */
+
+  cwp = sregs.psr & PSR_CWP;
+
+  /* Calculate the invalid window from the wim. */
+
+  for (invwin = 0; invwin <= PSR_CWP; invwin++)
+    if ((sregs.wim >> invwin) & 1)
+      break;
+
+  /* Start saving with the window after the invalid window. */
+
+  invwin = (invwin - 1) & PSR_CWP;
+
+  for (win = invwin; ; win = (win - 1) & PSR_CWP)
+    {
+      uint32 sp;
+      int i;
+
+      sp = sregs.r[(win * 16 + 14) & 0x7f];
+
+      for (i = 0; i < 16; i++)
+	memory_write (11, sp + 4 * i, &sregs.r[(win * 16 + 16 + i) & 0x7f], 2,
+		      &ws);
+
+      if (win == cwp)
+	break;
+    }
+}
 
 void
 sim_resume(int step, int siggnal)
 {
     simstat = run_sim(&sregs, 1, 0, 0);
+
+    flush_windows ();
 }
 
 void
-- 
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