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Diffstat (limited to 'README.md')
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1 files changed, 39 insertions, 32 deletions
@@ -1,40 +1,52 @@ -This is a mouse driver for Windows 3.x with VirtualBox mouse integration support. -I have tested it with Windows 3.0 in real and 386 enhanced modes, Windows 3.11 in 386 enhanced mode -with paging on, as well as Windows 95 (Windows 9x can use 16-bit mouse drivers). +This is a DOS mouse driver as a TSR written in C and compilable using OpenWatcom C. +It is not going to stand out in either compatibility, performance, or memory usage; +the main goal is to have a driver that is at least a bit easier to hack on, for experimentation. -# Install +Like any other DOS mouse driver, it partially supports the MS Mouse API (int 33h), but has +some additional features: + +* Implements the hooks required for DOS boxes inside Windows. + Multiple DOS boxes can use this driver simultaneously, + and clicks in the DOS window will be passed through to the correct running DOS application. + +* PS/2 Wheel and 3 button mouse support, using the API from CuteMouse. -Download [vbmouse.flp](https://depot.javispedro.com/vbox/vbmouse1.flp) -(a floppy image containing vbmouse.drv and oemsetup.inf) and insert it into your virtual machine. +* Integration with VirtualBox: in many DOS programs, the mouse can be used without requiring capture, + and will seamlessly integrate with the mouse cursor in the host. + The mouse cursor will be rendered by the host rather than the guest OS, appearing much more responsive. + Programs/games that utilize relative mouse motion information will be "jumpy" when this is enabled, + so this integration can be disabled (either from the VirtualBox menu or by using `vbmouse integ off` after loading + the driver). -In the Windows Setup program (accessible either via SETUP.EXE on an installed Windows or via -the corresponding icon in Program Manager), go to -Options → Change system configuration → Mouse → Select "Other mouse..." → Search in "A:" -→ "VirtualBox PS/2 Mouse". -Select the "VirtualBox PS/2 Mouse" in the Mouse section again. +* A companion driver for Windows 3.x that uses this driver (via int33h) instead of accessing the mouse directly, + so that Windows 3.x gains some of the features of this driver (like mouse integration in VirtualBox). + Wheel doesn't work in Windows 3.x right now. -Alternatively, you can copy vbmouse.drv to your WINDOWS\SYSTEM directory and edit WINDOWS\SYSTEM.INI 's mouse.drv line to point to it, e.g. +Note that it does not support serial mice or anything other than PS/2. - [boot] - mouse.drv = vbmouse.drv +# Install -This later option also works with Windows 9x. +Just run vbmouse. # Building This requires [OpenWatcom 2.0](http://open-watcom.github.io/), albeit it may work with an older version, and was only tested on a Linux host. -The included makefile is a wmake makefile. To build it just enter the OpenWatcom environment and run `wmake vbmouse.drv`. -`wmake flp` may be used to build a floppy image containg oemsetup.inf and vbmouse.drv for easier installation. +The included makefile is a wmake makefile. To build it just enter the OpenWatcom environment and run `wmake flp`. +This will create a floppy image containing vbmouse.exe plus the Windows 3.x driver (oemsetup.inf and vbmouse.drv). # Design This is at its core a driver for a plain PS/2 mouse driver, using the PS/2 BIOS. If running outside VirtualBox, in fact it will behave like a PS/2 mouse driver. -However, it removes a lot of checks for older platforms and is mostly written in C rather than assembly, -so hopefully it is easier to understand than the Windows sample drivers. + +The .exe file is comprised of two segments, the first one contains the resident part, +while the second one contains the command line interface. This second segment +is dropped once the driver goes resident. + +### VirtualBox communication The VirtualBox guest integrations present itself as a PCI device to the guest. Thanks to the BIOS, the device is already pre-configured. @@ -45,21 +57,16 @@ The host will write back the response in the same buffer. Further details are available in [OSDev](https://wiki.osdev.org/VirtualBox_Guest_Additions). The only challenge here is getting the physical address (what the VirtualBox PCI device expects) -corresponding to a logical address (segment:offset) as seen from inside Windows. -In real mode Windows, the segment can be converted to a physical address without difficulty. -In 386 enhanced mode, the segment is actually a selector, but turns out one can obtain the base -of a selector with the `GetSelectorBase()` WINAPI. -However, if paging is enabled, that only computes the linear address, which is still not the same -as the physical address. -In this case, the [Virtual DMA services](https://en.wikipedia.org/wiki/Virtual_DMA_Services) are used -to obtain the physical address, even though we are not doing DMA. +corresponding to a logical address (segment:offset). +While running under real mode DOS, the segment can be converted to a physical address without difficulty. +However, when using DOS extenders, EMM386, Windows in 386 mode, etc. DOS is actually run +in virtual 8086 mode, and the logical address may not correspond to a physical address. +However, most DOS extenders still map conventional memory 1:1, and for those who don't, +the driver uses the [Virtual DMA services](https://en.wikipedia.org/wiki/Virtual_DMA_Services) +to obtain the physical address. When VirtualBox is told that the guest wants absolute mouse information, VirtualBox will stop sending relative mouse information via the PS/2 mouse. However, the PS/2 controller will still send interrupts whenever mouse motion happens, and it will still report mouse button presses. In fact, the only way -to obtain mouse button presses is still through the PS/2 controller. -Thus, the only difference between this driver and a standard PS/2 mouse driver is that, -when an interrupt from the mouse comes in, we won't report the relative mouse motion to Windows. -Rather, we call into VirtualBox (right from the PS/2 BIOS interrupt handler) -to obtain the absolution mouse position, and report that to Windows. +to obtain mouse button presses (and wheel movement) is still through the PS/2 controller. |