MPS table patcher for the ASUS P/I-P65UP5

src/include/86box/chipset.h

@@ -47,6 +47,8 @@ extern const device_t   i440ex_device;
 extern const device_t	i440bx_device;
 extern const device_t	i440zx_device;
 
+extern const device_t	ioapic_device;
+
 /* OPTi */
 extern const device_t	opti495_device;
 extern const device_t	opti5x7_device;

src/ioapic.c

@@ -0,0 +1,130 @@
+/*
+ * 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 distribution.
+ *
+ *		Skeleton I/O APIC implementation, currently housing the MPS
+ *              table patcher for machines that require it.
+ *
+ *
+ *
+ * Author:	RichardG, <richardg867@gmail.com>
+ *
+ *		Copyright 2020 RichardG.
+ */
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#define HAVE_STDARG_H
+#include <86box/86box.h>
+#include <86box/io.h>
+#include <86box/device.h>
+#include <86box/machine.h>
+#include <86box/mem.h>
+#include <86box/chipset.h>
+
+
+typedef struct {
+    uint8_t dummy;
+} ioapic_t;
+
+#define ENABLE_IOAPIC_LOG 1
+#ifdef ENABLE_IOAPIC_LOG
+int ioapic_do_log = ENABLE_IOAPIC_LOG;
+
+
+static void
+ioapic_log(const char *fmt, ...)
+{
+    va_list ap;
+
+    if (ioapic_do_log) {
+	va_start(ap, fmt);
+	pclog_ex(fmt, ap);
+	va_end(ap);
+    }
+}
+#else
+#define ioapic_log(fmt, ...)
+#endif
+
+
+static void
+ioapic_write(uint16_t port, uint8_t val, void *priv)
+{
+    uint32_t addr, pcmp;
+
+    /* target POST FF, issued by Award before jumping to the bootloader */
+    if (val != 0xff)
+    	return;
+
+    ioapic_log("IOAPIC: Caught POST %02X\n", val);
+
+    /* The _MP_ table must be located in the BIOS area, the EBDA, or the last 1k of conventional
+       memory; at a 16-byte boundary in all cases. Award writes both tables to the BIOS area. */
+    for (addr = 0xf0000; addr <= 0xfffff; addr += 16) {
+    	/* check signature for the _MP_ table (Floating Point Structure) */
+    	if (mem_readl_phys(addr) != 0x5f504d5f) /* ASCII "_MP_" */
+    		continue;
+
+    	/* read and check pointer to the PCMP table (Configuration Table) */
+        pcmp = mem_readl_phys(addr + 4);
+        if ((pcmp < 0xf0000) || (pcmp > 0xfffff) || (mem_readl_phys(pcmp) != 0x504d4350)) /* ASCII "PCMP" */
+        	continue;
+
+        /* patch over the signature on both tables */
+        ioapic_log("IOAPIC: Patching _MP_ [%08x] and PCMP [%08x] tables\n", addr, pcmp);
+        ram[addr] = ram[addr + 1] = ram[addr + 2] = ram[addr + 3] = 0xff;
+        ram[pcmp] = ram[pcmp + 1] = ram[pcmp + 2] = ram[pcmp + 3] = 0xff;
+
+        break;
+    }
+}
+
+
+static void
+ioapic_reset(ioapic_t *dev)
+{
+}
+
+
+static void
+ioapic_close(void *priv)
+{
+    ioapic_t *dev = (ioapic_t *) priv;
+
+    io_removehandler(0x80, 1,
+		     NULL, NULL, NULL, ioapic_write, NULL, NULL,  NULL);
+
+    free(dev);
+}
+
+
+static void *
+ioapic_init(const device_t *info)
+{
+    ioapic_t *dev = (ioapic_t *) malloc(sizeof(ioapic_t));
+    memset(dev, 0, sizeof(ioapic_t));
+
+    ioapic_reset(dev);
+
+    io_sethandler(0x80, 1,
+		  NULL, NULL, NULL, ioapic_write, NULL, NULL,  NULL);
+
+    return dev;
+}
+
+
+const device_t ioapic_device = {
+    "I/O APIC",
+    DEVICE_AT,
+    0,
+    ioapic_init, ioapic_close, NULL,
+    NULL, NULL, NULL,
+    NULL
+};

src/machine/m_at_socket8.c

@@ -176,6 +176,7 @@ machine_at_p65up5_common_init(const machine_t *model, const device_t *northbridg
     device_add(&keyboard_ps2_ami_pci_device);
     device_add(&w83877f_device);
     device_add(&intel_flash_bxt_device);
+    device_add(&ioapic_device);
 }
 
 int

src/win/Makefile.mingw

@@ -527,7 +527,7 @@ CPUOBJ		:= cpu.o cpu_table.o \
 		    $(DYNARECOBJ)
 
 CHIPSETOBJ	:= acc2168.o acer_m3a.o cs8230.o ali1429.o headland.o \
-		    intel_4x0.o neat.o opti495.o opti5x7.o scamp.o scat.o \
+		    intel_4x0.o ioapic.o neat.o opti495.o opti5x7.o scamp.o scat.o \
 		    rabbit.o sis_85c471.o sis_85c496.o \
 		    via_apollo.o via_vpx.o wd76c10.o
 

src/win/Makefile_ndr.mingw

@@ -531,7 +531,7 @@ CPUOBJ		:= cpu.o cpu_table.o \
 		    $(DYNARECOBJ)
 
 CHIPSETOBJ	:= acc2168.o acer_m3a.o cs8230.o ali1429.o headland.o \
-		    intel_4x0.o neat.o opti495.o opti5x7.o scamp.o scat.o \
+		    intel_4x0.o ioapic.o neat.o opti495.o opti5x7.o scamp.o scat.o \
 		    rabbit.o sis_85c471.o sis_85c496.o \
 		    via_apollo.o via_vpx.o wd76c10.o