From c84c1c636d81320ad19c479374044e9727c4c273 Mon Sep 17 00:00:00 2001
From: Jeremy Penner <jeremy@sporktania.com>
Date: Mon, 1 Jan 2024 21:27:33 -0500
Subject: [PATCH] Make mamelink wait until the C64 has booted to begin
 accepting commands

Fix detection of entry point
Type "SYS" command to "jump" instead of modifying the program counter
directly - arbitrary PC modification can sometimes lead to freezes
Reduce console output spam
---
 mamelink/README.md                     |  2 +-
 mamelink/down.c                        |  2 +-
 mamelink/mameplugins/mamelink/init.lua | 12 ++++++------
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/mamelink/README.md b/mamelink/README.md
index 6c4e2b1..a004d42 100644
--- a/mamelink/README.md
+++ b/mamelink/README.md
@@ -5,7 +5,7 @@ A compatibility shim for Lucasfilm Games' "fastlink", using a MAME plugin to imp
 Run `make`. Assumes a POSIX-like environment. Works On My Machine, totally untested on anything besides Linux.
 
 ## Booting reno
-Run `./start`. Assumes that `mame` is in the current path, with C64 ROMs installed.
+Run `./start`. Assumes that `mame` is in the current path, with C64 ROMs installed. MAME will start, and you will probably need to press a key to start the emulated C64 booting. Once the C64 has completed startup, `reno` will automatically begin uploading, and when it is complete, you will see the command `SYS2122` automatically be entered into the emulator. After a few more seconds, Reno will start.
 
 ## How It Works
 It's a terrible, awful, very bad, no good hack, but it does the trick and should hopefully be portable, even to an enscripten-type browser environment. To send a command to the `mamelink` plugin, the `mamelink.c` library creates a file called `mameplugins/mamelink/linkin` with
diff --git a/mamelink/down.c b/mamelink/down.c
index 416bc41..de481cd 100644
--- a/mamelink/down.c
+++ b/mamelink/down.c
@@ -59,7 +59,7 @@ void sendAbsoluteSegments() {
         readbytes(count);
         printf("Segment: %4x-%4x\n", start, end);
         down(buf, count, start);
-        if (start == end) {
+        if (start == end && entryPoint == 0) {
             entryPoint = start;
         }
     }
diff --git a/mamelink/mameplugins/mamelink/init.lua b/mamelink/mameplugins/mamelink/init.lua
index 7ab5b01..01ead96 100644
--- a/mamelink/mameplugins/mamelink/init.lua
+++ b/mamelink/mameplugins/mamelink/init.lua
@@ -39,7 +39,8 @@ local function fastlink(bytein, byteout)
             end
         elseif command == 4 then -- jump
             local address = readword(bytein)
-            cpu.state["PC"].value = address
+            -- cpu.state["PC"].value = address
+            emu.keypost("SYS" .. tostring(address) .. "\n")
         else 
             print("Unknown command: " .. tostring(command))
         end
@@ -47,9 +48,8 @@ local function fastlink(bytein, byteout)
 end
 
 local function is_booted()
-    local cpu = manager.machine.devices[":u7"]
-    local mem = cpu.spaces.program
-    return mem
+    -- wait for machine to be started, and allow 3 seconds for booting before accepting commands
+    return manager.machine.time:as_double() > 3
 end
 
 function exports.startplugin()
@@ -77,14 +77,14 @@ function exports.startplugin()
         io.outfile:write(string.char(byte))
     end
 
-    print(coroutine.resume(link, bytein, byteout))
+    assert(coroutine.resume(link, bytein, byteout))
 
     emu.register_periodic(function()
         if not is_booted() then return end
         linkio.infile = io.open(infilename, "rb")
         if linkio.infile then
             linkio.outfile = io.open(pendingfilename, "wb")
-            print(coroutine.resume(link))
+            assert(coroutine.resume(link))
             linkio.infile:close()
             linkio.infile = nil
             linkio.outfile:close()