Add VMware absolute-pointer backdoor (port 0x5658)

Makefile

@@ -79,7 +79,7 @@ CARGO_FLAGS_SAFE=\
 CARGO_FLAGS=$(CARGO_FLAGS_SAFE) -C target-feature=+bulk-memory -C target-feature=+multivalue -C target-feature=+simd128
 
 CORE_FILES=cjs.js const.js io.js main.js lib.js buffer.js ide.js pci.js floppy.js \
-	   dma.js pit.js vga.js ps2.js rtc.js uart.js \
+	   dma.js pit.js vga.js ps2.js rtc.js uart.js vmware.js \
 	   acpi.js iso9660.js \
 	   state.js ne2k.js sb16.js virtio.js virtio_console.js virtio_net.js virtio_balloon.js \
 	   bus.js log.js cpu.js \

docs/windows-9x.md

@@ -101,6 +101,18 @@ The default VGA display driver only supports 640x480x4 video mode, to fix this,
 5. Select "VESA ISA" adapter and press "OK".
 6. After installing, restart Windows.
 
+## Enabling absolute mouse positioning (VBMOUSE)
+
+v86 emulates the VMware absolute pointing device. With an absolute mouse driver installed in the guest, the guest cursor follows the host cursor directly, without having to lock the mouse.
+
+[VBADOS](https://git.javispedro.com/cgit/vbados.git/about/) provides VBMOUSE, an open-source DOS mouse driver with VMware mouse support, together with a 16-bit Windows mouse driver on top of it that Windows 9x can use.
+
+1. Download [vbados.flp](https://depot.javispedro.com/vbox/vbados/vbados.flp) and mount it as a floppy image (or copy its contents into the guest in some other way).
+2. Copy `VBMOUSE.EXE` from the floppy to the hard disk (for example to `C:\VBADOS`) and `VBMOUSE.DRV` to `C:\WINDOWS\SYSTEM`.
+3. Add `C:\VBADOS\VBMOUSE.EXE` to `C:\AUTOEXEC.BAT`, so the DOS part of the driver is loaded before Windows starts.
+4. In `C:\WINDOWS\SYSTEM.INI`, change the `mouse.drv` line in the `[boot]` section to `mouse.drv=vbmouse.drv`.
+5. Restart Windows.
+
 ## CPU idling on Windows 95
 See about [installing AmnHLT](cpu-idling.md#windows-9x-using-amnhlt).
 

src/browser/main.js

@@ -2681,6 +2681,7 @@ function init_ui(profile, settings, emulator)
     var last_instr_counter = 0;
     var interval = null;
     var os_uses_mouse = false;
+    var os_uses_absolute_mouse = false;
     var total_instructions = 0;
 
     function update_info()
@@ -2828,6 +2829,11 @@ function init_ui(profile, settings, emulator)
         $("info_mouse_enabled").textContent = is_enabled ? "Yes" : "No";
     });
 
+    emulator.add_listener("vmware-absolute-mouse", function(is_enabled)
+    {
+        os_uses_absolute_mouse = is_enabled;
+    });
+
     emulator.add_listener("screen-set-size", function(args)
     {
         const [w, h, bpp] = args;
@@ -3216,7 +3222,11 @@ function init_ui(profile, settings, emulator)
             emulator.speaker_adapter.audio_context.resume();
         }
 
-        if(mouse_is_enabled && os_uses_mouse)
+        // No need to lock the mouse if the guest tracks the host cursor
+        // through the absolute pointing device. The "Lock mouse" button can
+        // still be used, e.g. for games (movement is then sent as relative
+        // deltas).
+        if(mouse_is_enabled && os_uses_mouse && !os_uses_absolute_mouse)
         {
             emulator.lock_mouse();
         }

src/browser/mouse.js

@@ -58,6 +58,7 @@ export function MouseAdapter(bus, screen_container)
         window.removeEventListener("mousedown", mousedown_handler, false);
         window.removeEventListener("mouseup", mouseup_handler, false);
         window.removeEventListener("wheel", mousewheel_handler, { passive: false });
+        document.removeEventListener("pointerlockchange", pointerlockchange_handler, false);
     };
 
     this.init = function()
@@ -75,9 +76,15 @@ export function MouseAdapter(bus, screen_container)
         window.addEventListener("mousedown", mousedown_handler, false);
         window.addEventListener("mouseup", mouseup_handler, false);
         window.addEventListener("wheel", mousewheel_handler, { passive: false });
+        document.addEventListener("pointerlockchange", pointerlockchange_handler, false);
     };
     this.init();
 
+    function pointerlockchange_handler()
+    {
+        mouse.bus.send("mouse-pointer-lock", !!document.pointerLockElement);
+    }
+
     function is_child(child, parent)
     {
         while(child.parentNode)
@@ -225,7 +232,9 @@ export function MouseAdapter(bus, screen_container)
 
         mouse.bus.send("mouse-delta", [delta_x, delta_y]);
 
-        if(screen_container)
+        // Under pointer lock the page coordinates don't change, so no
+        // meaningful absolute position can be reported
+        if(screen_container && !document.pointerLockElement)
         {
             const absolute_x = e.pageX - screen_container.offsetLeft;
             const absolute_y = e.pageY - screen_container.offsetTop;

src/browser/starter.js

@@ -288,6 +288,20 @@ V86.prototype.continue_init = async function(emulator, options)
         this.mouse_adapter = new MouseAdapter(this.bus, screen_options.container);
     }
 
+    // Pointer lock is not needed while the guest uses absolute pointer
+    // positions (the guest cursor follows the host cursor), so release it
+    // when the guest driver enables absolute positioning
+    this.absolute_pointer_enabled = false;
+    this.bus.register("vmware-absolute-mouse", function(enabled)
+    {
+        if(enabled && !this.absolute_pointer_enabled &&
+            typeof document !== "undefined" && document.pointerLockElement)
+        {
+            document.exitPointerLock();
+        }
+        this.absolute_pointer_enabled = enabled;
+    }, this);
+
     if(screen_options.container)
     {
         this.screen_adapter = new ScreenAdapter(screen_options, () => this.v86.cpu.devices.vga && this.v86.cpu.devices.vga.screen_fill_buffer());

src/cpu.js

@@ -24,6 +24,7 @@ import { IO } from "./io.js";
 import { VirtioConsole } from "./virtio_console.js";
 import { PCI } from "./pci.js";
 import { PS2 } from "./ps2.js";
+import { VMwareMouse } from "./vmware.js";
 import { read_elf } from "./elf.js";
 
 import { FloppyController } from "./floppy.js";
@@ -570,6 +571,7 @@ CPU.prototype.get_state = function()
     state[86] = this.last_result;
     state[87] = this.fpu_status_word;
     state[88] = this.mxcsr;
+    state[89] = this.devices.vmware;
 
     return state;
 };
@@ -738,6 +740,7 @@ CPU.prototype.set_state = function(state)
     this.devices.virtio_console && this.devices.virtio_console.set_state(state[82]);
     this.devices.virtio_net && this.devices.virtio_net.set_state(state[83]);
     this.devices.virtio_balloon && this.devices.virtio_balloon.set_state(state[84]);
+    this.devices.vmware && state[89] && this.devices.vmware.set_state(state[89]);
 
     this.fw_value = state[62];
 
@@ -1176,6 +1179,7 @@ CPU.prototype.init = function(settings, device_bus)
         this.devices.vga = new VGAScreen(this, device_bus, settings.screen, settings.vga_memory_size || 8 * 1024 * 1024);
 
         this.devices.ps2 = new PS2(this, device_bus);
+        this.devices.vmware = new VMwareMouse(this, device_bus);
 
         this.devices.uart0 = new UART(this, 0x3F8, device_bus);