Added safe mode option B_SAFEMODE_4_GB_MEMORY_LIMIT (plus a boot loader menu

item) and kernel settings option "4gb_memory_limit". Enabling either one
causes the memory beyond 4 GB to be ignored.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@37225 a95241bf-73f2-0310-859d-f6bbb57e9c96

data/settings/kernel/drivers/kernel

@@ -59,3 +59,6 @@ acpi true
 #acpi_avoid_full_init true
 	# Avoids running _INI and _STA methods and final object initialization,
 	# which may be used to for debugging ACPI issues, false by default
+
+#4gb_memory_limit true
+	# Ignores all memory beyond the 4 GB address limit. Default is false.

headers/private/system/safemode_defs.h

@@ -15,6 +15,7 @@
 #define B_SAFEMODE_DISABLE_SMP				"disable_smp"
 #define B_SAFEMODE_DISABLE_HYPER_THREADING	"disable_hyperthreading"
 #define B_SAFEMODE_FAIL_SAFE_VIDEO_MODE		"fail_safe_video_mode"
+#define B_SAFEMODE_4_GB_MEMORY_LIMIT		"4gb_memory_limit"
 
 #if DEBUG_SPINLOCK_LATENCIES
 #	define B_SAFEMODE_DISABLE_LATENCY_CHECK	"disable_latency_check"

src/system/boot/loader/load_driver_settings.cpp

@@ -13,6 +13,8 @@
 #include <OS.h>
 #include <drivers/driver_settings.h>
 
+#include <safemode_defs.h>
+
 #include <boot/driver_settings.h>
 #include <boot/kernel_args.h>
 #include <boot/stage2.h>
@@ -58,6 +60,20 @@ load_driver_settings_file(Directory* directory, const char* name)
 }
 
 
+static void
+apply_boot_settings(void* kernelSettings, void* safemodeSettings)
+{
+#if B_HAIKU_PHYSICAL_BITS > 32
+	if (get_driver_boolean_parameter(kernelSettings, "4gb_memory_limit", false,
+			false)
+		|| get_driver_boolean_parameter(safemodeSettings,
+			B_SAFEMODE_4_GB_MEMORY_LIMIT, false, false)) {
+		ignore_physical_memory_ranges_beyond_4gb();
+	}
+#endif
+}
+
+
 //	#pragma mark -
 
 
@@ -133,3 +149,18 @@ add_safe_mode_settings(char* settings)
 
 	return B_OK;
 }
+
+
+void
+apply_boot_settings()
+{
+	void* kernelSettings = load_driver_settings("kernel");
+	void* safemodeSettings = load_driver_settings(B_SAFEMODE_DRIVER_SETTINGS);
+
+	apply_boot_settings(kernelSettings, safemodeSettings);
+
+	if (safemodeSettings != NULL)
+		unload_driver_settings(safemodeSettings);
+	if (kernelSettings)
+		unload_driver_settings(kernelSettings);
+}

src/system/boot/loader/load_driver_settings.h

@@ -13,4 +13,7 @@ extern status_t add_safe_mode_settings(char *buffer);
 extern status_t add_stage2_driver_settings(stage2_args *args);
 extern status_t load_driver_settings(stage2_args *args, Directory *volume);
 
+extern void apply_boot_settings();
+
+
 #endif	/* LOAD_DRIVER_SETTINGS_H */

src/system/boot/loader/main.cpp

@@ -113,6 +113,9 @@ main(stage2_args *args)
 			load_modules(args, volume);
 			load_driver_settings(args, volume);
 
+			// apply boot settings
+			apply_boot_settings();
+
 			// set up kernel args version info
 			gKernelArgs.kernel_args_size = sizeof(kernel_args);
 			gKernelArgs.version = CURRENT_KERNEL_ARGS_VERSION;

src/system/boot/loader/menu.cpp

@@ -673,6 +673,28 @@ add_safe_mode_menu()
     item->SetHelpText("Disables IDE DMA, increasing IDE compatibilty "
 		"at the expense of performance.");
 
+#if B_HAIKU_PHYSICAL_BITS > 32
+	// check whether we have memory beyond 4 GB
+	bool hasMemoryBeyond4GB = false;
+	for (uint32 i = 0; i < gKernelArgs.num_physical_memory_ranges; i++) {
+		phys_addr_range& range = gKernelArgs.physical_memory_range[i];
+		if (range.start >= (phys_addr_t)1 << 32) {
+			hasMemoryBeyond4GB = true;
+			break;
+		}
+	}
+
+	// ... add the menu, if so
+	if (hasMemoryBeyond4GB) {
+		safeMenu->AddItem(
+			item = new(nothrow) MenuItem("Ignore memory beyond 4 GiB"));
+		item->SetData(B_SAFEMODE_4_GB_MEMORY_LIMIT);
+		item->SetType(MENU_ITEM_MARKABLE);
+		item->SetHelpText("Ignores all memory beyond the 4 GiB address limit, "
+			"overriding the setting in the kernel settings file.");
+	}
+#endif
+
 	platform_add_menus(safeMenu);
 
 	safeMenu->AddSeparatorItem();