usblgoff: Add tool for disabling USB legacy emulation

.github/workflows/build.yml

@@ -42,6 +42,10 @@ jobs:
           wmake
           make -f Makefile.uefi ARCH=x86_64
           python3 pciids.py
+      - name: Build `usblgoff`
+        run: |
+          cd ${{ github.workspace }}/usblgoff
+          wmake
       - uses: actions/upload-artifact@v2
         with:
           name: probing-tools-${{ github.sha }}
@@ -52,6 +56,7 @@ jobs:
             ac97/*.md
             acpi/*.md
             pcireg/*.md
+            usblgoff/*.md
 
   newbasic:
     name: NewBasic

.gitignore

@@ -23,4 +23,4 @@ pci?????.bin
 # Binaries
 *.exe
 *.com
-*.efi
+*.efi

clib/clib.c

@@ -386,6 +386,34 @@ pci_get_io_bar(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg, uint16_t siz
 }
 
 
+#ifdef IS_32BIT
+uint32_t
+pci_get_mem_bar(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg, uint32_t size, const char *name)
+{
+    uint32_t ret;
+
+    printf("%s memory BAR is ", name);
+
+    /* Read BAR register. */
+    ret = pci_readl(bus, dev, func, reg);
+    if ((ret & 0x00000001) || (ret == 0xffffffff)) {
+	printf("invalid! (%08X)", ret);
+	ret = 0;
+    } else {
+	/* Don't even try to find a valid memory range if the BAR is unassigned. */
+	ret &= ~(size - 1);
+	if (ret)
+		printf("assigned to %08X", ret);
+	else
+		printf("unassigned!");
+    }
+
+    printf("\n");
+    return ret;
+}
+#endif
+
+
 int
 pci_init()
 {

clib/clib.h

@@ -34,6 +34,9 @@
 #ifndef __POSIX_UEFI__
 # define FMT_FLOAT_SUPPORTED	1
 #endif
+#if !defined(__WATCOMC__) || defined(M_I386)
+# define IS_32BIT	1
+#endif
 
 
 #pragma pack(push, 0)
@@ -124,6 +127,9 @@ extern uint16_t	io_find_range(uint16_t size);
 /* PCI functions. */
 extern uint32_t	pci_cf8(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg);
 extern uint16_t	pci_get_io_bar(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg, uint16_t size, const char *name);
+#ifdef IS_32BIT
+extern uint32_t	pci_get_mem_bar(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg, uint32_t size, const char *name);
+#endif
 extern int	pci_init();
 extern uint8_t	pci_readb(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg);
 extern uint16_t	pci_readw(uint8_t bus, uint8_t dev, uint8_t func, uint8_t reg);

clib/watcom.mk

@@ -18,10 +18,12 @@
 # Establish host-specific stuff.
 !ifdef __UNIX__
 DEL		= rm -f
+COPY		= cp
 CP437		= cp437
 SLASH		= /
 !else
 DEL		= del
+COPY		= copy /y
 CP437		= cp437.exe
 SLASH		= \
 !if "$(SYSTEM)" == "HOST"
@@ -74,6 +76,9 @@ all:		..$(SLASH)cp437$(SLASH)$(CP437) $(DEST)
 
 # Main target.
 $(DEST):	$(OBJS)
+!if "$(SYSTEM)" == "PMODEW"
+		$(COPY) %WATCOM%$(SLASH)binw$(SLASH)pmodew.exe .$(SLASH)
+!endif
 		%write $@.lnk NAME   $@
 !if "$(SYSTEM)" != "HOST"
 		%write $@.lnk SYSTEM $(SYSTEM)

usblgoff/Makefile

@@ -0,0 +1,22 @@
+#
+# 86Box		A hypervisor and IBM PC system emulator that specializes in
+#		running old operating systems and software designed for IBM
+#		PC systems and compatibles from 1981 through fairly recent
+#		system designs based on the PCI bus.
+#
+#		This file is part of the 86Box Probing Tools distribution.
+#
+#		Makefile for compiling C-based tools with Watcom.
+#
+#
+#
+# Authors:	RichardG, <richardg867@gmail.com>
+#
+#		Copyright 2021 RichardG.
+#
+
+SYSTEM	= PMODEW
+OBJS	= usblgoff.obj clib.obj
+DEST	= USBLGOFF.EXE
+
+!include ../clib/watcom.mk

usblgoff/README.md

@@ -0,0 +1,12 @@
+usblgoff
+========
+DOS tool for disabling USB legacy emulation to allow for running keyboard controller probing tools.
+
+Usage
+-----
+Run `USBLGOFF.EXE` on a system with USB. The I/O traps set by onboard USB controllers and a handful of chipsets will be disabled, and the virtual keyboard controller created by the BIOS for USB input emulation should no longer interfere with KBC probing tools such as [amikey](../amikey) until the system is rebooted.
+
+Building
+--------
+* **Windows:** Run `wmake` from an OpenWatcom "Build Environment" command prompt.
+* **Linux:** Run `wmake` with OpenWatcom tools present in `$PATH`.

usblgoff/usblgoff.c

@@ -0,0 +1,152 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		This file is part of the 86Box Probing Tools distribution.
+ *
+ *		USB legacy emulation disable tool.
+ *
+ *
+ *
+ * Authors:	RichardG, <richardg867@gmail.com>
+ *
+ *		Copyright 2022 RichardG.
+ *
+ * ┌──────────────────────────────────────────────────────────────┐
+ * │ This file is UTF-8 encoded. If this text is surrounded by    │
+ * │ garbage, please tell your editor to open this file as UTF-8. │
+ * └──────────────────────────────────────────────────────────────┘
+ */
+#include <inttypes.h>
+#include <stdio.h>
+#include <string.h>
+#include "clib.h"
+
+
+static void
+pci_scan_callback(uint8_t bus, uint8_t dev, uint8_t func,
+		  uint16_t ven_id, uint16_t dev_id)
+{
+    uint8_t i;
+    uint16_t j, start, end;
+#ifdef IS_32BIT
+    uint32_t mmio_base, *mmio;
+#endif
+
+#ifdef IS_32BIT
+    /* Disable southbridge I/O traps. */
+    if ((ven_id == 0x8086) && (((dev_id >= 0x2640) && (dev_id <= 0x2642)) /* ICH6 */ ||
+			       ((dev_id >= 0x27b0) && (dev_id <= 0x27bd)) /* ICH7 */ ||
+			       ((dev_id >= 0x2810) && (dev_id <= 0x2815)) /* ICH8 */ ||
+			       ((dev_id >= 0x2912) && (dev_id <= 0x2919)) /* ICH9 */ ||
+			       ((dev_id >= 0x3a14) && (dev_id <= 0x3a1a)) /* ICH10 */)) {
+	printf("Found ICH6-10 LPC bridge %04X at bus %02X device %02X function %d\n", dev_id, bus, dev, func);
+
+	/* Get RCBA. */
+	printf("> RCBA is ");
+	mmio_base = pci_readl(bus, dev, func, 0xf0) & ~0x00003fff;
+	if ((mmio_base & 0x00000001) && (mmio_base != 0xffffffff)) {
+		printf("assigned to %08X\n", mmio_base);
+		mmio = (uint32_t *) mmio_base;
+
+		/* Disable all relevant I/O traps. */
+		for (i = 0; i < 4; i++) {
+			/* Check if the trap is enabled. */
+			j = (0x1e80 | (i << 3)) >> 2;
+			if (mmio[j] & 0x00000001) {
+				start = mmio[j] & 0xfffc;
+				end = (mmio[j] >> 16) & 0xfc; /* temporarily just the mask */
+				printf("> Trap %d (%04X+%02X)", i, start, end);
+				end += start; /* now the actual end */
+
+				/* Check if the trap covers the KBC ports. */
+				if (((start <= 0x60) && (end >= 0x60)) ||
+				    ((start <= 0x64) && (end >= 0x64))) {
+					/* Clear TRSE bit. */
+					mmio[j] &= ~0x00000001;
+
+					/* Check if the bit was actually cleared. */
+					if (mmio[j] & 0x00000001)
+						printf("enable bit stuck! (%08X%08X)\n", mmio[j | 1], mmio[j]);
+					else
+						printf("disabled\n");
+				} else {
+					printf("not relevant\n");
+				}
+			}
+		}
+	} else {
+		printf("unassigned! (%08X)\n", mmio_base);
+	}
+
+	return;
+    }
+#endif
+
+    /* Skip non-USB devices. */
+    if (pci_readw(bus, dev, func, 0x0a) != 0x0c03)
+	return;
+
+    /* Read progif code. */
+    i = pci_readb(bus, dev, func, 0x09);
+
+    /* Act according to the device class. */
+    if (i == 0x00) { /* UHCI */
+	printf("Found UHCI USB controller at bus %02X device %02X function %d\n", bus, dev, func);
+
+	/* Clear 60/64h trap/SMI R/W bits. */
+	j = pci_readw(bus, dev, func, 0xc0);
+	pci_writew(bus, dev, func, 0xc0, j & ~0x000f);
+
+	/* Check if the bits were actually cleared. */
+	j = pci_readw(bus, dev, func, 0xc0);
+	if (j & 0x000f)
+		printf("> I/O trap bits stuck! (%04X)\n", j);
+	else
+		printf("> I/O traps disabled\n");
+    } else if (i == 0x10) { /* OHCI */
+	printf("Found OHCI USB controller at bus %02X device %02X function %d\n", bus, dev, func);
+
+#ifdef IS_32BIT
+	/* Get MMIO base address. */
+	mmio_base = pci_get_mem_bar(bus, dev, func, 0x10, 4096, "> MMIO");
+	if (mmio_base) {
+		mmio = (uint32_t *) mmio_base;
+
+		/* Clear EmulationEnable bit. */
+		mmio[0x100 >> 2] &= ~0x00000001;
+
+		/* Check if the bit was actually cleared. */
+		if (mmio[0x100 >> 2] & 0x00000001)
+			printf("> Emulation bit stuck! (%08X)\n", mmio[0x100 >> 2]);
+		else
+			printf("> Emulation disabled\n");
+	}
+#else
+	printf("> OHCI not supported on 16-bit build!\n");
+#endif
+    } else if ((i != 0x20) && (i != 0x30)) { /* not EHCI or XHCI */
+	printf("Found unknown USB controller type %02X at bus %02X device %02X function %d\n", i, bus, dev, func);
+    }
+}
+
+
+int
+main(int argc, char **argv)
+{
+    uint8_t dev, func;
+
+    /* Disable stdout buffering. */
+    term_unbuffer_stdout();
+
+    /* Initialize PCI, and exit in case of failure. */
+    if (!pci_init())
+	return 1;
+
+    /* Scan PCI bus 0. */
+    pci_scan_bus(0, pci_scan_callback);
+
+    return 0;
+}