Added advanced PCI option 'noagp' for the i440BX chipset.

Since AGP support is incomplete, it may be useful to disable this subsystem.

bochs/.bochsrc

@@ -565,7 +565,8 @@ mouse: enabled=0
 #  PCI chipset. These options can be specified as comma-separated values.
 #  By default the "Bochs i440FX" chipset enables the ACPI and HPET devices, but
 #  original i440FX doesn't support them. The options 'noacpi' and 'nohpet' make
-#  it possible to disable them.
+#  it possible to disable them. The option 'noagp' disables the incomplete AGP
+#  subsystem of the i440BX chipset.
 #
 # Example:
 #   pci: enabled=1, chipset=i440fx, slot1=pcivga, slot2=ne2k, advopts=noacpi

bochs/CHANGES

@@ -64,7 +64,8 @@ Detailed change log :
       either to disable the DDC feature or to read the monitor EDID from file.
   - PCI (general)
     - Added config parameter to set up advanced PCI options. Now it is possible
-      to disable ACPI or HPET in case the i440FX chipset is selected.
+      to disable ACPI or HPET in case the i440FX chipset is selected. For the
+      i440BX chipset it is possible to disable the incomplete AGP subsystem.
   - USB
     - Added keyboard emulation with most of the keys supported.
     - Added support for USB packet logging in PCAP format.

bochs/bios/rombios.h

@@ -257,6 +257,7 @@
 #define PCI_DEVICE_ID_INTEL_82441       0x1237
 #define PCI_DEVICE_ID_INTEL_82443       0x7190
 #define PCI_DEVICE_ID_INTEL_82443_1     0x7191
+#define PCI_DEVICE_ID_INTEL_82443_NOAGP 0x7192
 #define PCI_DEVICE_ID_INTEL_82371FB_0   0x122e
 #define PCI_DEVICE_ID_INTEL_82371FB_1   0x1230
 #define PCI_DEVICE_ID_INTEL_82371SB_0   0x7000

bochs/bios/rombios32.c

@@ -782,7 +782,8 @@ static void pci_bios_init_bridges(PCIDevice *d)
       } else if (device_id == PCI_DEVICE_ID_INTEL_82441 || device_id == PCI_DEVICE_ID_INTEL_82437) {
         /* i440FX / i430FX PCI bridge */
         bios_shadow_init(d);
-      } else if (device_id == PCI_DEVICE_ID_INTEL_82443) {
+      } else if ((device_id == PCI_DEVICE_ID_INTEL_82443) ||
+                 (device_id == PCI_DEVICE_ID_INTEL_82443_NOAGP)) {
         /* i440BX PCI bridge */
         bios_shadow_init(d);
         addr = find_pir_table();
@@ -795,9 +796,13 @@ static void pci_bios_init_bridges(PCIDevice *d)
         writeb(pir + 0x41, 0x48); // 3rd entry: 2nd slot
         writeb(pir + 0x51, 0x50); // 4th entry: 3rd slot
         writeb(pir + 0x61, 0x58); // 5th entry: 4th slot
-        writeb(pir + 0x70, 0x01); // 6th entry: AGP bus
+        if (device_id == PCI_DEVICE_ID_INTEL_82443) {
-        writeb(pir + 0x71, 0x00); // 6th entry: AGP slot
+          writeb(pir + 0x70, 0x01); // 6th entry: AGP bus
-        pci_config_writeb(d, 0xb4, 0x30); /* AGP aperture size 64 MB */
+          writeb(pir + 0x71, 0x00); // 6th entry: AGP slot
+          pci_config_writeb(d, 0xb4, 0x30); /* AGP aperture size 64 MB */
+        } else {
+          writeb(pir + 0x71, 0x60); // 6th entry: 5th slot
+        }
       } else if (device_id == PCI_DEVICE_ID_INTEL_82443_1) {
         /* i440BX PCI/AGP bridge */
         pci_config_writew(d, 0x04, 0x0107);

bochs/doc/docbook/user/user.dbk

@@ -4017,7 +4017,8 @@ With the advanced PCI options it is possible to control the behaviour of the
 PCI chipset. These options can be specified as comma-separated values.
 By default the "Bochs i440FX" chipset enables the ACPI and HPET devices, but
 original i440FX doesn't support them. The options 'noacpi' and 'nohpet' make
-it possible to disable them.
+it possible to disable them. The option 'noagp' disables the incomplete AGP
+subsystem of the i440BX chipset.
 </para>
 </section>
 

bochs/doc/man/bochsrc.5

@@ -1,5 +1,5 @@
 .\"Document Author:  Timothy R. Butler   -   tbutler@uninetsolutions.com"
-.TH bochsrc 5 "11 Jun 2021" "bochsrc" "The Bochs Project"
+.TH bochsrc 5 "27 Jun 2021" "bochsrc" "The Bochs Project"
 .\"SKIP_SECTION"
 .SH NAME
 bochsrc \- Configuration file for Bochs.
@@ -625,7 +625,8 @@ With the advanced PCI options it is possible to control the behaviour of the
 PCI chipset. These options can be specified as comma-separated values.
 By default the "Bochs i440FX" chipset enables the ACPI and HPET devices, but
 original i440FX doesn't support them. The options 'noacpi' and 'nohpet' make
-it possible to disable them.
+it possible to disable them. The option 'noagp' disables the incomplete AGP
+subsystem of the i440BX chipset.
 
 Example:
   pci: enabled=1, chipset=i440fx, slot1=pcivga, slot2=ne2k, advopts=noacpi

bochs/gui/siminterface.cc

@@ -799,8 +799,7 @@ bool bx_real_sim_c::is_pci_device(const char *name)
 bool bx_real_sim_c::is_agp_device(const char *name)
 {
 #if BX_SUPPORT_PCI
-  if (get_param_bool(BXPN_PCI_ENABLED)->get() &&
+  if (get_param_bool(BXPN_PCI_ENABLED)->get() && DEV_agp_present()) {
-      (SIM->get_param_enum(BXPN_PCI_CHIPSET)->get() == BX_PCI_CHIPSET_I440BX)) {
     const char *device = SIM->get_param_enum("pci.slot.5")->get_selected();
     if (!strcmp(name, device)) {
       return 1;

bochs/iodev/devices.cc

@@ -192,7 +192,9 @@ void bx_devices_c::init(BX_MEM_C *newmem)
   if (pci.enabled) {
 #if BX_SUPPORT_PCI
     if (chipset == BX_PCI_CHIPSET_I430FX) {
-      pci.advopts = (BX_PCI_ADVOPT_NOHPET | BX_PCI_ADVOPT_NOACPI);
+      pci.advopts = (BX_PCI_ADVOPT_NOHPET | BX_PCI_ADVOPT_NOACPI | BX_PCI_ADVOPT_NOAGP);
+    } else if (chipset == BX_PCI_CHIPSET_I440FX) {
+      pci.advopts = BX_PCI_ADVOPT_NOAGP;
     } else {
       pci.advopts = 0;
     }
@@ -207,6 +209,12 @@ void bx_devices_c::init(BX_MEM_C *newmem)
         }
       } else if (!strcmp(argv[i], "nohpet")) {
         pci.advopts |= BX_PCI_ADVOPT_NOHPET;
+      } else if (!strcmp(argv[i], "noagp")) {
+        if (chipset == BX_PCI_CHIPSET_I440BX) {
+          pci.advopts |= BX_PCI_ADVOPT_NOAGP;
+        } else {
+          BX_ERROR(("Disabling AGP not supported by PCI chipset"));
+        }
       } else {
         BX_ERROR(("Unknown advanced PCI option '%s'", argv[i]));
       }
@@ -362,7 +370,7 @@ void bx_devices_c::init(BX_MEM_C *newmem)
   const char *device;
 
   if (pci.enabled) {
-    if (chipset == BX_PCI_CHIPSET_I440BX) {
+    if ((chipset == BX_PCI_CHIPSET_I440BX) && is_agp_present()) {
       device = SIM->get_param_enum("pci.slot.5")->get_selected();
       if (strcmp(device, "none") && !pci.slot_used[4]) {
         BX_PANIC(("Unknown plugin '%s' at AGP slot", device));
@@ -1100,6 +1108,15 @@ bool bx_devices_c::is_harddrv_enabled(void)
   return 0;
 }
 
+bool bx_devices_c::is_agp_present(void)
+{
+#if BX_SUPPORT_PCI
+  return (pci.enabled && ((pci.advopts & BX_PCI_ADVOPT_NOAGP) == 0));
+#else
+  return 0;
+#endif
+}
+
 void bx_devices_c::add_sound_device(void)
 {
   sound_device_count++;
@@ -1358,7 +1375,8 @@ bool bx_devices_c::register_pci_handlers(bx_pci_device_c *dev,
 
   if (strcmp(name, "pci") && strcmp(name, "pci2isa") && strcmp(name, "pci_ide")
       && ((*devfunc & 0xf8) == 0x00)) {
-    if (SIM->get_param_enum(BXPN_PCI_CHIPSET)->get() == BX_PCI_CHIPSET_I440BX) {
+    if ((SIM->get_param_enum(BXPN_PCI_CHIPSET)->get() == BX_PCI_CHIPSET_I440BX) &&
+        (is_agp_present())) {
       max_pci_slots = 4;
     }
     if (bus == 0) {

bochs/iodev/iodev.h

@@ -126,6 +126,7 @@ class cdrom_base_c;
 
 #define BX_PCI_ADVOPT_NOACPI 0x01
 #define BX_PCI_ADVOPT_NOHPET 0x02
+#define BX_PCI_ADVOPT_NOAGP  0x04
 
 typedef struct {
   Bit8u  type;
@@ -443,6 +444,7 @@ public:
                        Bit32u *addr, Bit8u *pci_conf, unsigned size,
                        const Bit8u *iomask, const char *name);
 #endif
+  bool is_agp_present();
 
   static void timer_handler(void *);
   void timer(void);

bochs/iodev/pci.cc

@@ -82,21 +82,33 @@ void bx_pci_bridge_c::init(void)
   if (BX_PCI_THIS chipset == BX_PCI_CHIPSET_I430FX) {
     init_pci_conf(0x8086, 0x0122, 0x02, 0x060000, 0x00, 0);
   } else if (BX_PCI_THIS chipset == BX_PCI_CHIPSET_I440BX) {
-    init_pci_conf(0x8086, 0x7190, 0x02, 0x060000, 0x00, 0);
+    if (DEV_agp_present()) {
-    BX_PCI_THIS pci_conf[0x10] = 0x08;
+      init_pci_conf(0x8086, 0x7190, 0x02, 0x060000, 0x00, 0);
-    init_bar_mem(0, 0xf0000000, agp_ap_read_handler, agp_ap_write_handler);
+      BX_PCI_THIS pci_conf[0x06] = 0x10;
-    BX_PCI_THIS pci_conf[0x06] = 0x10;
+      BX_PCI_THIS pci_conf[0x10] = 0x08;
-    BX_PCI_THIS pci_conf[0x34] = 0xa0;
+      init_bar_mem(0, 0xf0000000, agp_ap_read_handler, agp_ap_write_handler);
-    BX_PCI_THIS pci_conf[0xa0] = 0x02;
+      BX_PCI_THIS pci_conf[0x34] = 0xa0;
-    BX_PCI_THIS pci_conf[0xa2] = 0x10;
+      BX_PCI_THIS pci_conf[0xa0] = 0x02;
-    BX_PCI_THIS pci_conf[0xa4] = 0x03;
+      BX_PCI_THIS pci_conf[0xa2] = 0x10;
-    BX_PCI_THIS pci_conf[0xa5] = 0x02;
+      BX_PCI_THIS pci_conf[0xa4] = 0x03;
-    BX_PCI_THIS pci_conf[0xa7] = 0x1f;
+      BX_PCI_THIS pci_conf[0xa5] = 0x02;
+      BX_PCI_THIS pci_conf[0xa7] = 0x1f;
+      BX_PCI_THIS vbridge = new bx_pci_vbridge_c();
+      BX_PCI_THIS vbridge->init();
+    } else {
+      init_pci_conf(0x8086, 0x7192, 0x02, 0x060000, 0x00, 0);
+      BX_PCI_THIS pci_conf[0x7a] = 0x02;
+    }
+    // 'Intel reserved' values
+    BX_PCI_THIS pci_conf[0x71] = 0x1f;
+    BX_PCI_THIS pci_conf[0x94] = 0x04;
+    BX_PCI_THIS pci_conf[0x95] = 0x61;
+    BX_PCI_THIS pci_conf[0x99] = 0x05;
+    BX_PCI_THIS pci_conf[0xc8] = 0x18;
+    BX_PCI_THIS pci_conf[0xc9] = 0x0c;
     BX_PCI_THIS pci_conf[0xf3] = 0xf8;
     BX_PCI_THIS pci_conf[0xf8] = 0x20;
     BX_PCI_THIS pci_conf[0xf9] = 0x0f;
-    BX_PCI_THIS vbridge = new bx_pci_vbridge_c();
-    BX_PCI_THIS vbridge->init();
   } else { // i440FX
     init_pci_conf(0x8086, 0x1237, 0x00, 0x060000, 0x00, 0);
   }
@@ -204,7 +216,9 @@ bx_pci_bridge_c::reset(unsigned type)
     BX_PCI_THIS pci_conf[0x06] = 0x00;
     BX_PCI_THIS pci_conf[0x58] = 0x00;
   } else if (BX_PCI_THIS chipset == BX_PCI_CHIPSET_I440BX) {
-    BX_PCI_THIS vbridge->reset(type);
+    if (BX_PCI_THIS vbridge != NULL) {
+      BX_PCI_THIS vbridge->reset(type);
+    }
   } else { // i440FX
     BX_PCI_THIS pci_conf[0x06] = 0x80;
     BX_PCI_THIS pci_conf[0x51] = 0x01;
@@ -228,7 +242,7 @@ void bx_pci_bridge_c::register_state(void)
 {
   bx_list_c *list = new bx_list_c(SIM->get_bochs_root(), "pci_bridge", "PCI Bridge State");
   register_pci_state(list);
-  if (BX_PCI_THIS chipset == BX_PCI_CHIPSET_I440BX) {
+  if (BX_PCI_THIS vbridge != NULL) {
     BX_PCI_THIS vbridge->register_state();
   }
 }
@@ -236,7 +250,7 @@ void bx_pci_bridge_c::register_state(void)
 void bx_pci_bridge_c::after_restore_state(void)
 {
   BX_PCI_THIS smram_control(BX_PCI_THIS pci_conf[0x72]);
-  if (BX_PCI_THIS chipset == BX_PCI_CHIPSET_I440BX) {
+  if (BX_PCI_THIS vbridge != NULL) {
     BX_PCI_THIS vbridge->after_restore_state();
   }
 }
@@ -350,6 +364,10 @@ void bx_pci_bridge_c::pci_write_handler(Bit8u address, Bit32u value, unsigned io
       case 0x72:
         smram_control(value8); // SMRAM control register
         break;
+      case 0x7a:
+        BX_PCI_THIS pci_conf[address+i] &= 0x0a;
+        BX_PCI_THIS pci_conf[address+i] |= (value8 & 0xf5);
+        break;
       case 0xb4:
         if (BX_PCI_THIS chipset == BX_PCI_CHIPSET_I440BX) {
           BX_PCI_THIS pci_conf[address+i] = value8 & 0x3f;

bochs/plugin.h

@@ -234,6 +234,7 @@ extern "C" {
 #define DEV_ide_bmdma_start_transfer(a) \
   bx_devices.pluginPciIdeController->bmdma_start_transfer(a)
 #define DEV_acpi_generate_smi(a) bx_devices.pluginACPIController->generate_smi(a)
+#define DEV_agp_present() (bx_devices.is_agp_present())
 
 ///////// Speaker macros
 #define DEV_speaker_beep_on(frequency) bx_devices.pluginSpeaker->beep_on(frequency)