From 1ae3048aa85a0bdf0dedcf12414cf906f547caa4 Mon Sep 17 00:00:00 2001
From: Tau <tau@nowhere>
Date: Thu, 25 Jun 2020 20:47:42 -0400
Subject: [PATCH] Add ddrhook "COM4" passthrough mode

---
 src/main/ddrhook/_com4.c   |  4 ----
 src/main/ddrhook/dllmain.c | 42 ++++++++++++++++++++++++++++++--------
 src/main/ddrhook/p3io.c    |  6 ++++++
 3 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/src/main/ddrhook/_com4.c b/src/main/ddrhook/_com4.c
index 049c8ec..5decb5c 100644
--- a/src/main/ddrhook/_com4.c
+++ b/src/main/ddrhook/_com4.c
@@ -85,10 +85,6 @@ void com4_init(void)
 {
     uint8_t i;
 
-    /* This isn't a real COM port, we configure the core P3IO emulator code to
-       generate IRPs addressed to COM4 and then we intercept them. */
-
-    p3io_uart_set_path(0, L"COM4");
     ac_io_emu_init(&com4_ac_io_emu, L"COM4");
     ac_io_emu_hdxs_init(&com4_hdxs, &com4_ac_io_emu, lights_dispatcher);
 
diff --git a/src/main/ddrhook/dllmain.c b/src/main/ddrhook/dllmain.c
index 5971fb9..ca65817 100644
--- a/src/main/ddrhook/dllmain.c
+++ b/src/main/ddrhook/dllmain.c
@@ -32,7 +32,7 @@ static bool my_dll_entry_main(void);
 bool standard_def;
 bool _15khz;
 
-static const irp_handler_t ddrhook_handlers[] = {
+static const irp_handler_t ddrhook_com4_handlers[] = {
     p3io_emu_dispatch_irp,
     extio_dispatch_irp,
     spike_dispatch_irp,
@@ -40,15 +40,27 @@ static const irp_handler_t ddrhook_handlers[] = {
     com4_dispatch_irp,
 };
 
+static const irp_handler_t ddrhook_handlers[] = {
+    /* Same as above, but without COM4 emulation.
+       See ddrhook/p3io.c for details. */
+
+    p3io_emu_dispatch_irp,
+    extio_dispatch_irp,
+    spike_dispatch_irp,
+    usbmem_dispatch_irp,
+};
+
 static bool my_dll_entry_init(char *sidcode, struct property_node *param)
 {
     int argc;
     char **argv;
+    bool com4;
     bool ok;
     int i;
 
     log_info("--- Begin ddrhook dll_entry_init ---");
 
+    com4 = true;
     args_recover(&argc, &argv);
 
     for (i = 1; i < argc; i++) {
@@ -65,13 +77,25 @@ static bool my_dll_entry_init(char *sidcode, struct property_node *param)
             case 'w':
                 gfx_set_windowed();
 
+                break;
+
+            case 'u':
+                /* Don't emulate P3IO COM4 and its downstream devices, use the
+                   Windows COM4 port instead. */
+                com4 = false;
+
                 break;
         }
     }
 
     args_free(argc, argv);
 
-    iohook_init(ddrhook_handlers, lengthof(ddrhook_handlers));
+    if (com4) {
+        iohook_init(ddrhook_com4_handlers, lengthof(ddrhook_com4_handlers));
+    } else {
+        iohook_init(ddrhook_handlers, lengthof(ddrhook_handlers));
+    }
+
     rs232_hook_init();
 
     master_insert_hooks(NULL);
@@ -92,15 +116,17 @@ static bool my_dll_entry_init(char *sidcode, struct property_node *param)
         return false;
     }
 
-    log_info("Initializing card reader backend");
+    if (com4) {
+        log_info("Initializing card reader backend");
 
-    eam_io_set_loggers(
-        log_body_misc, log_body_info, log_body_warning, log_body_fatal);
+        eam_io_set_loggers(
+            log_body_misc, log_body_info, log_body_warning, log_body_fatal);
 
-    ok = eam_io_init(avs_thread_create, avs_thread_join, avs_thread_destroy);
+        ok = eam_io_init(avs_thread_create, avs_thread_join, avs_thread_destroy);
 
-    if (!ok) {
-        return false;
+        if (!ok) {
+            return false;
+        }
     }
 
     log_info("--- End ddrhook dll_entry_init ---");
diff --git a/src/main/ddrhook/p3io.c b/src/main/ddrhook/p3io.c
index 41186bd..424d9ef 100644
--- a/src/main/ddrhook/p3io.c
+++ b/src/main/ddrhook/p3io.c
@@ -29,6 +29,12 @@ static const struct p3io_ops p3io_ddr_ops = {
 
 void p3io_ddr_init(void)
 {
+    /* COM4 isn't a real COM port, we configure the core P3IO emulator code to
+       generate IRPs addressed to COM4 and then we possibly intercept them in
+       _com4.c (or possibly don't, in which case the communications will be
+       sent to the real COM4 on your system) */
+
+    p3io_uart_set_path(0, L"COM4");
     p3io_emu_init(&p3io_ddr_ops, NULL);
 }