[hatari-devel] Extensions to Hatari's Native Features support for debugging?

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

Douglas asked how one could direct native code asserts to
invoke Hatari debugger:
http://www.atari-forum.com/viewtopic.php?f=4&t=16682&p=239236#p239233


While one might try something hacky like this with --bios-intercept:
	XBios(255, "b pc=pc")

I think best would be to add direct support this this kind of operations
to Hatari's Native Features support, as that is easily extendable
(unlike XBios(255)):
	http://wiki.aranym.org/natfeats/proposal


For starters I was thinking of two additional NatFeats operations:

	"NF_DEBUGGER" -- invoke Hatari debugger
	"NF_COMMAND" -- same as Xbios(255)   [1]

Attached untested patch implements them to Hatari.

Comments, standalone test-code for NatFeats and suggestions for
other useful NatFeats commands would be welcome!

(especially the test-code, hint, hint...)


	- Eero

[1] I would like to eventually phase out "--bios-intercept"
    option and XBIOS calls doing extra things besides tracing.
	XBios_Rsconf() is probably already obsolete and XBios(255)
    can be replaced with NF_COMMAND, which leaves just a question
    of what to do about XBios_Scrdmp().

	If Bios interception were enabled always (with no side-effects),
    there could be a separate, better named option for enabling
    TOS/XBIOS screendump call making a Hatari screenshot.

diff -r 558497b06d63 src/debug/natfeats.c
--- a/src/debug/natfeats.c	Mon Oct 07 23:58:34 2013 +0200
+++ b/src/debug/natfeats.c	Thu Oct 10 23:51:38 2013 +0300
@@ -1,7 +1,7 @@
 /*
  * Hatari - natfeats.c
  * 
- * Copyright (C) 2012 by Eero Tamminen
+ * Copyright (C) 2012-2013 by Eero Tamminen
  *
  * This file is distributed under the GNU General Public License, version 2
  * or at your option any later version. Read the file gpl.txt for details.
@@ -20,6 +20,7 @@
 #include "stMemory.h"
 #include "m68000.h"
 #include "natfeats.h"
+#include "control.h"
 
 #define NF_DEBUG 1
 #if NF_DEBUG
@@ -34,6 +35,10 @@
  */
 
 
+/*
+ * Native Features shared with Aranym
+ */
+
 static bool nf_name(Uint32 stack, Uint32 subid, Uint32 *retval)
 {
 	Uint32 ptr, len;
@@ -91,6 +96,44 @@
 	return true;
 }
 
+/*
+ * Native Features specific to Hatari
+ */
+
+/**
+ * invoke debugger
+ */
+static bool nf_debugger(Uint32 stack, Uint32 subid, Uint32 *retval)
+{
+	Dprintf(("NF debugger()\n"));
+	M68000_SetSpecial(SPCFLAG_DEBUGGER);
+	return true;
+}
+
+/**
+ * execute Hatari (command line / debugger) command
+ */
+static bool nf_command(Uint32 stack, Uint32 subid, Uint32 *retval)
+{
+	Uint32 ptr;
+	char *str;
+
+	ptr = STMemory_ReadLong(stack);
+	Dprintf(("NF command(0x%x)\n", ptr));
+
+	if (!STMemory_ValidArea(ptr, 1)) {
+		M68000_BusError(ptr, BUS_ERROR_READ);
+		return false;
+	}
+	str = strdup((const char *)STRAM_ADDR(ptr));
+	if (str) {
+		Control_ProcessBuffer(str);
+		free(str);
+	}
+	return true;
+}
+
+
 /* ---------------------------- */
 
 #define FEATNAME_MAX 16
@@ -103,7 +146,9 @@
 	{ "NF_NAME",     false, nf_name },
 	{ "NF_VERSION",  false, nf_version },
 	{ "NF_STDERR",   false, nf_stderr },
-	{ "NF_SHUTDOWN", true,  nf_shutdown }
+	{ "NF_SHUTDOWN", true,  nf_shutdown },
+	{ "NF_DEBUGGER", false, nf_debugger },
+	{ "NF_COMMAND",  false, nf_command }
 };
 
 /* macros from Aranym */