Don't store a KMessage in kernel_args for the boot volume, only the buffer address/size.

Pointers in kernel_args are going to be changed to unconditionally use 64-bit
storage (to make kernel_args compatible with both the x86 and x86_64 kernels).
KMessage stores a pointer to its buffer, however since KMessage is used
outside of the boot code it is undesirable to change it to use 64-bit storage
for the pointer as it may add additional overhead on 32-bit builds. Therefore,
only store the buffer address and size and then construct a KMessage from
those in the kernel.

headers/private/kernel/boot/kernel_args.h

@@ -18,8 +18,6 @@
 #include <platform_kernel_args.h>
 #include <arch_kernel_args.h>
 
-#include <util/KMessage.h>
-
 #define CURRENT_KERNEL_ARGS_VERSION	1
 #define MAX_KERNEL_ARGS_RANGE		20
 
@@ -59,7 +57,9 @@ typedef struct kernel_args {
 	uint32		num_cpus;
 	addr_range	cpu_kstack[MAX_BOOT_CPUS];
 
-	KMessage	boot_volume;
+	// boot volume KMessage data
+	void		*boot_volume;
+	int32		boot_volume_size;
 
 	struct driver_settings_file *driver_settings;
 

headers/private/kernel/boot/stage2.h

@@ -8,10 +8,12 @@
 
 #include <boot/kernel_args.h>
 
+#include <util/KMessage.h>
 
 struct stage2_args;
 
 extern struct kernel_args gKernelArgs;
+extern KMessage gBootVolume;
 
 #ifdef __cplusplus
 extern "C" {

src/system/boot/loader/kernel_args.cpp

@@ -19,6 +19,7 @@
 static const size_t kChunkSize = 16 * B_PAGE_SIZE;
 
 kernel_args gKernelArgs;
+KMessage gBootVolume;
 
 static void* sFirstFree;
 static void* sLast;

src/system/boot/loader/loader.cpp

@@ -233,8 +233,7 @@ load_modules(stage2_args *args, Directory *volume)
 	// and now load all partitioning and file system modules
 	// needed to identify the boot volume
 
-	if (!gKernelArgs.boot_volume.GetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE,
-			false)) {
+	if (!gBootVolume.GetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE, false)) {
 		// iterate over the mounted volumes and load their file system
 		Partition *partition;
 		if (gRoot->GetPartitionFor(volume, &partition) == B_OK) {

src/system/boot/loader/main.cpp

@@ -40,9 +40,6 @@ main(stage2_args *args)
 	gKernelArgs.keep_debug_output_buffer = true;
 #endif
 
-	// construct boot_volume KMessage explicitely
-	new(&gKernelArgs.boot_volume) KMessage;
-
 	add_stage2_driver_settings(args);
 
 	platform_init_video();
@@ -123,16 +120,16 @@ main(stage2_args *args)
 			// clone the boot_volume KMessage into kernel accessible memory
 			// note, that we need to 4 byte align the buffer and thus allocate
 			// 3 more bytes
-			KMessage& bootVolume = gKernelArgs.boot_volume;
-			void* buffer = kernel_args_malloc(bootVolume.ContentSize() + 3);
+			void* buffer = kernel_args_malloc(gBootVolume.ContentSize() + 3);
 			if (!buffer) {
 				panic("Could not allocate memory for the boot volume kernel "
 					"arguments");
 			}
 
 			buffer = (void*)(((addr_t)buffer + 3) & ~(addr_t)0x3);
-			memcpy(buffer, bootVolume.Buffer(), bootVolume.ContentSize());
-			bootVolume.SetTo(buffer, bootVolume.ContentSize());
+			memcpy(buffer, gBootVolume.Buffer(), gBootVolume.ContentSize());
+			gKernelArgs.boot_volume = buffer;
+			gKernelArgs.boot_volume_size = gBootVolume.ContentSize();
 
 			// ToDo: cleanup, heap_release() etc.
 			platform_start_kernel();

src/system/boot/loader/menu.cpp

@@ -481,7 +481,7 @@ user_menu_boot_volume(Menu* menu, MenuItem* item)
 	bootItem->Select(true);
 	bootItem->SetData(item->Data());
 
-	gKernelArgs.boot_volume.SetBool(BOOT_VOLUME_USER_SELECTED, true);
+	gBootVolume.SetBool(BOOT_VOLUME_USER_SELECTED, true);
 	return true;
 }
 
@@ -712,7 +712,7 @@ add_boot_volume_menu(Directory* bootVolume)
 	menu->AddItem(item = new(nothrow) MenuItem("Return to main menu"));
 	item->SetType(MENU_ITEM_NO_CHOICE);
 
-	if (gKernelArgs.boot_volume.GetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE, false))
+	if (gBootVolume.GetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE, false))
 		menu->SetChoiceText("CD-ROM or hard drive");
 
 	return menu;

src/system/boot/loader/partitions.cpp

@@ -268,8 +268,8 @@ Partition::_Mount(file_system_module_info *module, Directory **_fileSystem)
 status_t
 Partition::Mount(Directory **_fileSystem, bool isBootDevice)
 {
-	if (isBootDevice && gKernelArgs.boot_volume.GetBool(
-			BOOT_VOLUME_BOOTED_FROM_IMAGE, false)) {
+	if (isBootDevice && gBootVolume.GetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE,
+			false)) {
 		return _Mount(&gTarFileSystemModule, _fileSystem);
 	}
 
@@ -293,8 +293,8 @@ Partition::Scan(bool mountFileSystems, bool isBootDevice)
 	// if we were not booted from the real boot device, we won't scan
 	// the device we were booted from (which is likely to be a slow
 	// floppy or CD)
-	if (isBootDevice && gKernelArgs.boot_volume.GetBool(
-			BOOT_VOLUME_BOOTED_FROM_IMAGE, false)) {
+	if (isBootDevice && gBootVolume.GetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE,
+			false)) {
 		return B_ENTRY_NOT_FOUND;
 	}
 

src/system/boot/loader/vfs.cpp

@@ -380,8 +380,7 @@ register_boot_file_system(Directory *volume)
 		return status;
 	}
 
-	gKernelArgs.boot_volume.SetInt64(BOOT_VOLUME_PARTITION_OFFSET,
-		partition->offset);
+	gBootVolume.SetInt64(BOOT_VOLUME_PARTITION_OFFSET, partition->offset);
 
 	Node *device = get_node_from(partition->FD());
 	if (device == NULL) {

src/system/boot/platform/amiga_m68k/devices.cpp

@@ -161,8 +161,7 @@ platform_add_boot_device(struct stage2_args *args, NodeList *devicesList)
 	TRACE(("boot drive ID: %x\n", gBootDriveID));
 
 //TODO
-	gKernelArgs.boot_volume.SetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE,
-		gBootedFromImage);
+	gBootVolume.SetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE, gBootedFromImage);
 
 	return B_OK;
 }

src/system/boot/platform/atari_m68k/devices.cpp

@@ -1182,8 +1182,7 @@ platform_add_boot_device(struct stage2_args *args, NodeList *devicesList)
 	}
 
 	TRACE(("boot drive size: %Ld bytes\n", drive->Size()));
-	gKernelArgs.boot_volume.SetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE,
-		gBootedFromImage);
+	gBootVolume.SetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE, gBootedFromImage);
 
 	return B_OK;
 }
@@ -1232,8 +1231,8 @@ platform_register_boot_device(Node *device)
 	check_cd_boot(drive);
 #endif
 
-	gKernelArgs.boot_volume.SetInt64("boot drive number", drive->DriveID());
-	gKernelArgs.boot_volume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE,
+	gBootVolume.SetInt64("boot drive number", drive->DriveID());
+	gBootVolume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE,
 		&drive->Identifier(), sizeof(disk_identifier));
 
 	return B_OK;

src/system/boot/platform/bios_ia32/devices.cpp

@@ -167,7 +167,7 @@ static bool sBlockDevicesAdded = false;
 static void
 check_cd_boot(BIOSDrive *drive)
 {
-	gKernelArgs.boot_volume.SetInt32(BOOT_METHOD, BOOT_METHOD_HARD_DISK);
+	gBootVolume.SetInt32(BOOT_METHOD, BOOT_METHOD_HARD_DISK);
 
 	if (drive->DriveID() != 0)
 		return;
@@ -185,7 +185,7 @@ check_cd_boot(BIOSDrive *drive)
 
 	specification_packet *packet = (specification_packet *)kDataSegmentScratch;
 	if (packet->media_type != 0)
-		gKernelArgs.boot_volume.SetInt32(BOOT_METHOD, BOOT_METHOD_CD);
+		gBootVolume.SetInt32(BOOT_METHOD, BOOT_METHOD_CD);
 
 #if 0
 	dprintf("got CD boot spec:\n");
@@ -841,8 +841,7 @@ platform_add_boot_device(struct stage2_args *args, NodeList *devicesList)
 	}
 
 	TRACE(("boot drive size: %Ld bytes\n", drive->Size()));
-	gKernelArgs.boot_volume.SetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE,
-		gBootedFromImage);
+	gBootVolume.SetBool(BOOT_VOLUME_BOOTED_FROM_IMAGE, gBootedFromImage);
 
 	return B_OK;
 }
@@ -888,8 +887,8 @@ platform_register_boot_device(Node *device)
 
 	check_cd_boot(drive);
 
-	gKernelArgs.boot_volume.SetInt64("boot drive number", drive->DriveID());
-	gKernelArgs.boot_volume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE,
+	gBootVolume.SetInt64("boot drive number", drive->DriveID());
+	gBootVolume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE,
 		&drive->Identifier(), sizeof(disk_identifier));
 
 	return B_OK;

src/system/boot/platform/cfe/devices.cpp

@@ -130,8 +130,8 @@ platform_register_boot_device(Node *device)
 	disk.device_type = UNKNOWN_DEVICE;
 	disk.device.unknown.size = device->Size();
 
-	gKernelArgs.boot_volume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE,
-		&disk, sizeof(disk_identifier));
+	gBootVolume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE, &disk,
+		sizeof(disk_identifier));
 
 	return B_OK;
 }		

src/system/boot/platform/openfirmware/devices.cpp

@@ -233,8 +233,8 @@ platform_register_boot_device(Node *device)
 	disk.device_type = UNKNOWN_DEVICE;
 	disk.device.unknown.size = device->Size();
 
-	gKernelArgs.boot_volume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE,
-		&disk, sizeof(disk_identifier));
+	gBootVolume.SetData(BOOT_VOLUME_DISK_IDENTIFIER, B_RAW_TYPE, &disk,
+		sizeof(disk_identifier));
 
 	return B_OK;
 }		

src/system/boot/platform/pxe_ia32/devices.cpp

@@ -152,15 +152,14 @@ platform_register_boot_device(Node *device)
 			rootPath = fileNameEnd + 1;
 	}
 
-	KMessage& bootVolume = gKernelArgs.boot_volume;
-	if (bootVolume.SetInt32(BOOT_METHOD, BOOT_METHOD_NET) != B_OK
-		|| bootVolume.AddInt64("client MAC",
+	if (gBootVolume.SetInt32(BOOT_METHOD, BOOT_METHOD_NET) != B_OK
+		|| gBootVolume.AddInt64("client MAC",
 			sTFTP.MACAddress().ToUInt64()) != B_OK
-		|| bootVolume.AddInt32("client IP", sTFTP.IPAddress()) != B_OK
-		|| bootVolume.AddInt32("server IP", sTFTP.ServerIPAddress()) != B_OK
-		|| bootVolume.AddInt32("server port", sTFTP.ServerPort()) != B_OK
+		|| gBootVolume.AddInt32("client IP", sTFTP.IPAddress()) != B_OK
+		|| gBootVolume.AddInt32("server IP", sTFTP.ServerIPAddress()) != B_OK
+		|| gBootVolume.AddInt32("server port", sTFTP.ServerPort()) != B_OK
 		|| (sTFTP.RootPath()
-			&& bootVolume.AddString("net root path", rootPath)
+			&& gBootVolume.AddString("net root path", rootPath)
 				!= B_OK)) {
 		return B_NO_MEMORY;
 	}

src/system/kernel/fs/vfs_boot.cpp

@@ -54,6 +54,8 @@ static struct {
 	{NULL}
 };
 
+static int32 sBootMethodType;
+
 // This can be used by other code to see if there is a boot file system already
 dev_t gBootDevice = -1;
 bool gReadOnlyBootDevice = false;
@@ -322,27 +324,28 @@ DiskBootMethod::SortPartitions(KPartition** partitions, int32 count)
 static status_t
 get_boot_partitions(kernel_args* args, PartitionStack& partitions)
 {
-	const KMessage& bootVolume = args->boot_volume;
+	KMessage bootVolume;
+	bootVolume.SetTo(args->boot_volume, args->boot_volume_size);
 
 	dprintf("get_boot_partitions(): boot volume message:\n");
 	bootVolume.Dump(&dprintf);
 
 	// create boot method
-	int32 bootMethodType = bootVolume.GetInt32(BOOT_METHOD, BOOT_METHOD_DEFAULT);
+	sBootMethodType = bootVolume.GetInt32(BOOT_METHOD, BOOT_METHOD_DEFAULT);
 	dprintf("get_boot_partitions(): boot method type: %" B_PRId32 "\n",
-		bootMethodType);
+		sBootMethodType);
 
 	BootMethod* bootMethod = NULL;
-	switch (bootMethodType) {
+	switch (sBootMethodType) {
 		case BOOT_METHOD_NET:
-			bootMethod = new(nothrow) NetBootMethod(bootVolume, bootMethodType);
+			bootMethod = new(nothrow) NetBootMethod(bootVolume, sBootMethodType);
 			break;
 
 		case BOOT_METHOD_HARD_DISK:
 		case BOOT_METHOD_CD:
 		default:
 			bootMethod = new(nothrow) DiskBootMethod(bootVolume,
-				bootMethodType);
+				sBootMethodType);
 			break;
 	}
 
@@ -415,7 +418,7 @@ get_boot_partitions(kernel_args* args, PartitionStack& partitions)
 
 	// sort partition list (e.g.. when booting from CD, CDs should come first in
 	// the list)
-	if (!args->boot_volume.GetBool(BOOT_VOLUME_USER_SELECTED, false))
+	if (!bootVolume.GetBool(BOOT_VOLUME_USER_SELECTED, false))
 		bootMethod->SortPartitions(partitions.Array(), partitions.CountItems());
 
 	return B_OK;
@@ -513,10 +516,8 @@ vfs_mount_boot_file_system(kernel_args* args)
 	// whether the module images the boot loader has pre-loaded are the same as
 	// on the boot volume. That is the case when booting from hard disk or CD,
 	// but not via network.
-	int32 bootMethodType = args->boot_volume.GetInt32(BOOT_METHOD,
-		BOOT_METHOD_DEFAULT);
-	bool bootingFromBootLoaderVolume = bootMethodType == BOOT_METHOD_HARD_DISK
-		|| bootMethodType == BOOT_METHOD_CD;
+	bool bootingFromBootLoaderVolume = sBootMethodType == BOOT_METHOD_HARD_DISK
+		|| sBootMethodType == BOOT_METHOD_CD;
 	module_init_post_boot_device(bootingFromBootLoaderVolume);
 
 	file_cache_init_post_boot_device();