From 06211c9933d008ae51aeb50979a8b49e5570c12b Mon Sep 17 00:00:00 2001
From: Jorj Bauer <jorj@jorj.org>
Date: Sat, 4 Jul 2020 14:46:55 -0400
Subject: [PATCH] add read and step out

---
 nix/debugger.cpp | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/nix/debugger.cpp b/nix/debugger.cpp
index 9425f8a..aea5cc4 100644
--- a/nix/debugger.cpp
+++ b/nix/debugger.cpp
@@ -91,10 +91,19 @@ bool getAddress(const char *buf, unsigned int *addrOut)
 #define HEXCHAR(x) ((x>='0'&&x<='9')?x-'0':(x>='a'&&x<='f')?x-'a'+10:(x>='A'&&x<='F')?x-'A'+10:(x=='i' || x=='I')?1:(x=='o' || x=='O')?0:0)
 #define FROMHEXP(p) ((HEXCHAR(*p) << 4) | HEXCHAR(*(p+1)))
 
+bool steppingOut = false;
+
 void Debugger::step()
 {
   static char buf[256];
 
+  // FIXME: add more than just RTS(0x60) here
+  if (steppingOut &&
+      g_vm->getMMU()->read(g_cpu->pc) != 0x60) {
+    return;
+  }
+  steppingOut = false;
+
   if (cd != -1) {
     // Print the status back out the socket
     uint8_t p = g_cpu->flags;
@@ -147,6 +156,11 @@ void Debugger::step()
       printf("Closing debugging socket\n");
       close(cd); cd=-1;
       break;
+      
+    case 'S':
+      steppingOut = true;
+      break;
+      
     case 'b': // Set breakpoint
       GETLN;
       if (getAddress(buf, &val)) {
@@ -186,6 +200,22 @@ void Debugger::step()
       }
       break;
 
+    case '*': // read 1 byte of memory. Use '* 0x<address>'
+      {
+	GETLN;
+	if (getAddress(buf, &val)) {
+	  sprintf(buf, "Memory location 0x%X: ", val);
+	  write(cd, buf, strlen(buf));
+	  val = g_vm->getMMU()->read(val);
+	  sprintf(buf, "0x%.2X\012\015", val);
+	  write(cd, buf, strlen(buf));
+	} else {
+	  sprintf(buf, "Invalid read\012\015");
+	  write(cd, buf, strlen(buf));
+	}
+      }
+      break;
+
     case 'G': // Goto (set PC)
       GETLN;
       if (getAddress(buf, &val)) {