initial import of DOS mouse driver

1 files changed, 275 insertions, 0 deletions

diff --git a/dosmain.c b/dosmain.c
new file mode 100644
index 0000000..36bea69
--- /dev/null
+++ b/dosmain.c
@@ -0,0 +1,275 @@
+/*
+ * VBMouse - DOS mouse driver exec entry point
+ * Copyright (C) 2022 Javier S. Pedro
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dos.h>
+#include <i86.h>
+
+#include "dlog.h"
+#include "ps2.h"
+#include "vbox.h"
+#include "dostsr.h"
+
+static unsigned get_resident_size(void)
+{
+	return FP_OFF(&resident_end);
+}
+
+static int set_integration(LPTSRDATA data, bool enable)
+{
+	if (enable) {
+		int err;
+
+		data->vbavail = false; // Reinitialize it even if already enabled
+
+		if ((err = vbox_init(&data->vb)) == 0) {
+			printf("Found VirtualBox device at IO 0x%x\n", data->vb.iobase);
+			printf("Found physical address for VBox communication 0x%lx\n", data->vb.buf_physaddr);
+
+			if ((err = vbox_report_guest_info(&data->vb, VBOXOSTYPE_DOS)) == 0) {
+				printf("VirtualBox integration enabled\n");
+				data->vbavail = true;
+			} else {
+				fprintf(stderr, "VirtualBox communication is not working, err=%d\n", err);
+				return err;
+			}
+		} else {
+			fprintf(stderr, "Cannot find VirtualBox PCI device, err=%d\n", err);
+			return err;
+		}
+	} else {
+		if (data->vbavail) {
+			vbox_set_mouse(&data->vb, false, false);
+			printf("Disabled VirtualBox integration\n");
+			data->vbavail = false;
+		} else {
+			printf("VirtualBox already disabled or not available\n");
+		}
+	}
+
+	return 0;
+}
+
+static int set_host_cursor(LPTSRDATA data, bool enable)
+{
+#if USE_VIRTUALBOX
+	if (data->vbavail) {
+		printf("Setting host cursor to %s\n", enable ? "enabled" : "disabled");
+		data->vbwantcursor = enable;
+	} else {
+		printf("VirtualBox integration is not available\n");
+	}
+#endif
+	return EXIT_SUCCESS;
+}
+
+static int configure_driver(LPTSRDATA data)
+{
+	int err;
+
+	// First check for PS/2 mouse availability
+	if ((err = ps2m_init(PS2_MOUSE_PLAIN_PACKET_SIZE))) {
+		fprintf(stderr, "Cannot init PS/2 mouse BIOS, err=%d\n", err);
+		// Can't do anything without PS/2
+		return err;
+	}
+
+#if USE_VIRTUALBOX
+	// Assume initially that we want integration and host cursor
+	 set_integration(data, true);
+	 data->vbwantcursor = data->vbavail;
+#endif
+
+	return 0;
+}
+
+static void deallocate_environment(uint16_t psp)
+{
+	// TODO : Too lazy to make PSP struct;
+	// 0x2C is offsetof the environment block field on the PSP
+	uint16_t __far *envblockP = (uint16_t __far *) MK_FP(psp, 0x2C);
+	_dos_freemem(*envblockP);
+	*envblockP = 0;
+}
+
+static int install_driver(LPTSRDATA data)
+{
+	unsigned int resident_size = get_resident_size();
+
+	// Not that this will do anything other than fragment memory, but why not...
+	deallocate_environment(_psp);
+
+	data->prev_int33_handler = _dos_getvect(0x33);
+
+	_dos_setvect(0x33, int33_isr);
+
+	_dos_keep(EXIT_SUCCESS, (256 + resident_size + 15) / 16);
+	return 0;
+}
+
+static bool check_if_driver_uninstallable(LPTSRDATA data)
+{
+	void (__interrupt __far *cur_int33_handler)() = _dos_getvect(0x33);
+	void (__interrupt __far *our_int33_handler)() = MK_FP(FP_SEG(data), FP_OFF(int33_isr));
+
+	if (cur_int33_handler != our_int33_handler) {
+		fprintf(stderr, "INT33 has been hooked by some other driver, removing anyway\n");
+		return true;
+	}
+
+	return true;
+}
+
+static int unconfigure_driver(LPTSRDATA data)
+{
+#if USE_VIRTUALBOX
+	if (data->vbavail) {
+		set_integration(data, false);
+	}
+#endif
+
+	ps2m_enable(false);
+	ps2m_set_callback(0);
+
+	return 0;
+}
+
+static int uninstall_driver(LPTSRDATA data)
+{
+	_dos_setvect(0x33, data->prev_int33_handler);
+
+	// Find and deallocate the PSP (including the entire program),
+	// it is always 256 bytes (16 paragraphs) before the TSR segment
+	_dos_freemem(FP_SEG(data) - 16);
+
+	printf("Driver uninstalled\n");
+
+	return 0;
+}
+
+static unsigned int33_call(unsigned ax);
+#pragma aux int33_call parm [ax] value [ax] = \
+	"int 0x33";
+
+static int driver_reset(void)
+{
+	printf("Reset mouse driver\n");
+	return int33_call(0x0) == 0xFFFF;
+}
+
+static int driver_not_found(void)
+{
+	fprintf(stderr, "Driver data not found (driver not installed?)\n");
+	return EXIT_FAILURE;
+}
+
+static void print_help(void)
+{
+	printf("\n"
+	    "Usage: \n"
+	    "\tVBMOUSE <ACTION>\n\n"
+	    "Supported actions:\n"
+	    "\tinstall           install the driver (default)\n"
+	    "\tuninstall         uninstall the driver from memory\n"
+	    "\tinteg <ON|OFF>    enable/disable virtualbox integration\n"
+	    "\thostcur <ON|OFF>  enable/disable mouse cursor rendering in host\n"
+	    "\treset             reset mouse driver settings\n"
+	);
+}
+
+static bool is_true(const char *s)
+{
+	return stricmp(s, "yes") == 0
+	       || stricmp(s, "y") == 0
+	       || stricmp(s, "on") == 0
+	       || stricmp(s, "true") == 0
+	       || stricmp(s, "enabled") == 0
+	       || stricmp(s, "enable") == 0
+	       || stricmp(s, "1") == 0;
+}
+
+static bool is_false(const char *s)
+{
+	return stricmp(s, "no") == 0
+	       || stricmp(s, "n") == 0
+	       || stricmp(s, "off") == 0
+	       || stricmp(s, "false") == 0
+	       || stricmp(s, "disabled") == 0
+	       || stricmp(s, "disable") == 0
+	       || stricmp(s, "0") == 0;
+}
+
+int main(int argc, const char *argv[])
+{
+	LPTSRDATA data = get_tsr_data(true);
+	int err, argi = 1;
+
+	printf("VBMouse %d.%d\n", DRIVER_VERSION_MAJOR, DRIVER_VERSION_MINOR);
+
+	if (argi >= argc || stricmp(argv[argi], "install") == 0) {
+		if (data) {
+			printf("VBMouse already installed\n");
+			return EXIT_SUCCESS;
+		}
+
+		data = get_tsr_data(false);
+		err = configure_driver(data);
+		if (err) return EXIT_FAILURE;
+		return install_driver(data);
+	} else if (stricmp(argv[argi], "uninstall") == 0) {
+		if (!data) return driver_not_found();
+		if (!check_if_driver_uninstallable(data)) {
+			return EXIT_FAILURE;
+		}
+		err = unconfigure_driver(data);
+		if (err) {
+			return EXIT_FAILURE;
+		}
+		return uninstall_driver(data);
+	} else if (stricmp(argv[argi], "integ") == 0) {
+		bool enable = true;
+
+		if (!data) return driver_not_found();
+
+		argi++;
+		if (argi < argc) {
+			if (is_false(argv[argi])) enable = false;
+		}
+
+		return set_integration(data, enable);
+	} else if (stricmp(argv[argi], "hostcur") == 0) {
+		bool enable = true;
+
+		if (!data) return driver_not_found();
+
+		argi++;
+		if (argi < argc) {
+			if (is_false(argv[argi])) enable = false;
+		}
+
+		return set_host_cursor(data, enable);
+	} else if (stricmp(argv[argi], "reset") == 0) {
+		return driver_reset();
+	}
+
+	print_help();
+	return EXIT_FAILURE;
+}