bootloader: Refactor semantics of platform_allocate_region() functions.

This cleans up a lot of subtle or hidden inconsistencies:

 * Drop the "exactAddress" parameter. It was added in hrev15708 (2005),
   but all callers in all bootloaders passed "false" to it until 2022,
   when one codepath in the ARM32 EFI loader started using it.

 * Adjust EFI's platform_allocate_lomem to platform_allocate_region_below,
   and add a platform_assign_kernel_address_for_region(). This allows the
   aforementioned ARM EFI codepath to continue to do what it wants,
   which is to get an identity-mapped trampoline page, without having
   functions with confusingly different semantics ("allocate_lomem"
   assigned the virtual addresses as identity-mapped unconditionally,
   but it didn't insert these into the virtual allocated ranges.)

   This also paves the way for other EFI loaders to use this method
   to allocate memory below whatever default the boot services
   would give us.

 * Drop fixed virtual address allocation for all arches on EFI, with the
   exception of fixed addresses inside KERNEL_LOAD_BASE, same as on
   other boot platforms. Anything which wants fixed virtual addresses
   outside that region can use the new "assign kernel address" method.

 * Validate kernel base and size against kMaxKernelSize, instead of
   assuming it fits. This matches behavior of other boot platforms.
   Ideally we would have some more generic routine for mapping the
   kernel, but this suffices for now.

Tested with x86_64 and ARM; both still boot (well, ARM boots as
far as it did before this commit, anyway.)

Change-Id: Ieb4fba752994101191a2335cb5395eb2b726fcbb
Reviewed-on: https://review.haiku-os.org/c/haiku/+/9024
Reviewed-by: waddlesplash <[email protected]>

headers/private/kernel/boot/platform.h

@@ -26,7 +26,7 @@ extern void platform_free_heap_region(void *_base, size_t size);
 
 /* MMU/memory functions */
 extern status_t platform_allocate_region(void **_virtualAddress, size_t size,
-	uint8 protection, bool exactAddress);
+	uint8 protection);
 extern status_t platform_free_region(void *address, size_t size);
 extern status_t platform_bootloader_address_to_kernel_address(void *address, addr_t *_result);
 extern status_t platform_kernel_address_to_bootloader_address(addr_t address, void **_result);

src/system/boot/arch/m68k/mmu.cpp

@@ -645,8 +645,7 @@ mmu_init(void)
 
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool /*exactAddress*/)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	void *address = mmu_allocate(*_address, size);
 	if (address == NULL)

src/system/boot/loader/elf.cpp

@@ -81,7 +81,7 @@ struct ELF32Class {
 		void** _mappedAddress)
 	{
 		status_t status = platform_allocate_region((void**)_address, size,
-			protection, false);
+			protection);
 		if (status != B_OK)
 			return status;
 
@@ -139,8 +139,7 @@ struct ELF64Class {
 		void* address = (void*)*_address;
 #endif
 
-		status_t status = platform_allocate_region(&address, size, protection,
-			false);
+		status_t status = platform_allocate_region(&address, size, protection);
 		if (status != B_OK)
 			return status;
 

src/system/boot/loader/file_systems/tarfs/tarfs.cpp

@@ -788,7 +788,7 @@ TarFS::Volume::_Inflate(boot::Partition* partition, void* cookie, off_t offset,
 			if (!out) {
 				// allocate memory for the uncompressed data
 				if (platform_allocate_region((void**)&out, kTarRegionSize,
-						B_READ_AREA | B_WRITE_AREA, false) != B_OK) {
+						B_READ_AREA | B_WRITE_AREA) != B_OK) {
 					TRACE(("tarfs: allocating region failed!\n"));
 					return B_NO_MEMORY;
 				}

src/system/boot/loader/kernel_args.cpp

@@ -435,7 +435,7 @@ kernel_args_malloc(size_t size, uint8 alignment)
 		// the block is so large, we'll allocate a new block for it
 		void* block = NULL;
 		if (platform_allocate_region(&block, alignedSize,
-				B_READ_AREA | B_WRITE_AREA, false) != B_OK) {
+				B_READ_AREA | B_WRITE_AREA) != B_OK) {
 			return NULL;
 		}
 
@@ -450,10 +450,8 @@ kernel_args_malloc(size_t size, uint8 alignment)
 
 	// just allocate a new block and "close" the old one
 	void* block = NULL;
-	if (platform_allocate_region(&block, kChunkSize, B_READ_AREA | B_WRITE_AREA,
-			false) != B_OK) {
+	if (platform_allocate_region(&block, kChunkSize, B_READ_AREA | B_WRITE_AREA) != B_OK)
 		return NULL;
-	}
 
 	sFirstFree = (void*)((addr_t)block + alignedSize);
 	sLast = block;

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

@@ -643,8 +643,7 @@ mmu_init(void)
 
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool /*exactAddress*/)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	void *address = mmu_allocate(*_address, size);
 	if (address == NULL)

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

@@ -648,8 +648,7 @@ mmu_init(void)
 
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool /*exactAddress*/)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	void *address = mmu_allocate(*_address, size);
 	if (address == NULL)

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

@@ -806,8 +806,7 @@ mmu_init(void)
 
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool /*exactAddress*/)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	void *address = mmu_allocate(*_address, size);
 	if (address == NULL)

src/system/boot/platform/efi/arch/arm/arch_mmu.cpp

@@ -219,7 +219,7 @@ static void
 arch_mmu_allocate_page_tables(void)
 {
 	if (platform_allocate_region((void **)&sPageDirectory,
-		ARM_MMU_L1_TABLE_SIZE + ALIGN_PAGEDIR + PAGE_TABLE_AREA_SIZE, 0, false) != B_OK)
+			ARM_MMU_L1_TABLE_SIZE + ALIGN_PAGEDIR + PAGE_TABLE_AREA_SIZE, 0) != B_OK)
 		panic("Failed to allocate page directory.");
 	sPageDirectory = (uint32 *)ROUNDUP((uint32)sPageDirectory, ALIGN_PAGEDIR);
 	memset(sPageDirectory, 0, ARM_MMU_L1_TABLE_SIZE);
@@ -238,10 +238,13 @@ arch_mmu_allocate_page_tables(void)
 static void
 arch_mmu_allocate_vector_table(void)
 {
-	if (platform_allocate_region((void **)&sVectorTable, B_PAGE_SIZE, 0, false) != B_OK)
+	void *vectorTable = NULL;
+	if (platform_allocate_region(&vectorTable, B_PAGE_SIZE, 0) != B_OK)
 		panic("Failed to allocate vector table.");
+	if (platform_assign_kernel_address_for_region(vectorTable, (addr_t)sVectorTable) != B_OK)
+		panic("Failed to assign vector table address");
 
-	memset(sVectorTable, 0, B_PAGE_SIZE);
+	memset(vectorTable, 0, B_PAGE_SIZE);
 }
 
 

src/system/boot/platform/efi/arch/arm/arch_start.cpp

@@ -58,25 +58,30 @@ static void *
 allocate_trampoline_page(void)
 {
 	void *trampolinePage = NULL;
-	if (platform_allocate_lomem(&trampolinePage, B_PAGE_SIZE) == B_OK)
-		return trampolinePage;
+	if (platform_allocate_region_below(&trampolinePage, B_PAGE_SIZE,
+			KERNEL_LOAD_BASE - B_PAGE_SIZE) == B_OK) {
+		if (platform_assign_kernel_address_for_region(trampolinePage,
+				(addr_t)trampolinePage) == B_OK) {
+			return trampolinePage;
+		}
 
-	trampolinePage = (void *)get_next_virtual_address(B_PAGE_SIZE);
-	if (platform_allocate_region(&trampolinePage, B_PAGE_SIZE, 0, true) == B_OK)
-		return trampolinePage;
+		if (platform_free_region(trampolinePage, B_PAGE_SIZE) != B_OK)
+			return NULL;
+	}
 
 	trampolinePage = NULL;
-	if (platform_allocate_region(&trampolinePage, B_PAGE_SIZE, 0, false) != B_OK)
-		return NULL;
+	if (platform_allocate_region(&trampolinePage, B_PAGE_SIZE, 0) == B_OK) {
+		if (platform_assign_kernel_address_for_region(trampolinePage,
+				(addr_t)trampolinePage) == B_OK) {
+			ASSERT_ALWAYS((uint32)trampolinePage >= 0x88000000);
+			return trampolinePage;
+		}
 
-	if (platform_free_region(trampolinePage, B_PAGE_SIZE) != B_OK)
-		return NULL;
+		if (platform_free_region(trampolinePage, B_PAGE_SIZE) != B_OK)
+			return NULL;
+	}
 
-	if (platform_allocate_region(&trampolinePage, B_PAGE_SIZE, 0, true) != B_OK)
-		return NULL;
-
-	ASSERT_ALWAYS((uint32_t)trampolinePage >= 0x88000000);
-	return trampolinePage;
+	return NULL;
 }
 
 
@@ -86,7 +91,7 @@ arch_start_kernel(addr_t kernelEntry)
 	// Allocate virtual memory for kernel args
 	struct kernel_args *kernelArgs = NULL;
 	if (platform_allocate_region((void **)&kernelArgs,
-			sizeof(struct kernel_args), 0, false) != B_OK)
+			sizeof(struct kernel_args), 0) != B_OK)
 		panic("Failed to allocate kernel args.");
 
 	addr_t virtKernelArgs;

src/system/boot/platform/efi/arch/arm64/arch_mmu.h

@@ -240,7 +240,7 @@ public:
 		uint64* page = NULL;
 #if 0
 		// BUG: allocation here overlaps assigned memory ...
-		if (platform_allocate_region((void **)&page, size, 0, false) == B_OK) {
+		if (platform_allocate_region((void **)&page, size, 0) == B_OK) {
 #else
 		// TODO: luckly size == B_PAGE_SIZE == 4KB ...
 		page = reinterpret_cast<uint64*>(mmu_allocate_page());

src/system/boot/platform/efi/arch/riscv64/arch_smp.cpp

@@ -189,9 +189,9 @@ arch_smp_init_other_cpus(void)
 		void * stack = NULL;
 		const size_t size = KERNEL_STACK_SIZE
 			+ KERNEL_STACK_GUARD_PAGES * B_PAGE_SIZE;
-		if (platform_allocate_region(&stack, size, 0, false) != B_OK) {
+		if (platform_allocate_region(&stack, size, 0) != B_OK)
 			panic("Unable to allocate AP stack");
-		}
+
 		memset(stack, 0, size);
 		gKernelArgs.cpu_kstack[i].start = fix_address((uint64_t)stack);
 		gKernelArgs.cpu_kstack[i].size = size;

src/system/boot/platform/efi/arch/riscv64/arch_start.cpp

@@ -48,7 +48,7 @@ arch_start_kernel(addr_t kernelEntry)
 	// Allocate virtual memory for kernel args
 	struct kernel_args *kernelArgs = NULL;
 	if (platform_allocate_region((void **)&kernelArgs,
-			sizeof(struct kernel_args), 0, false) != B_OK)
+			sizeof(struct kernel_args), 0) != B_OK)
 		panic("Failed to allocate kernel args.");
 
 	addr_t virtKernelArgs;

src/system/boot/platform/efi/arch/x86/arch_mmu.cpp

@@ -97,7 +97,7 @@ arch_mmu_init_gdt(gdt_idt_descr &bootGDTDescriptor)
 	segment_descriptor *bootGDT = NULL;
 
 	if (platform_allocate_region((void **)&bootGDT,
-			BOOT_GDT_SEGMENT_COUNT * sizeof(segment_descriptor), 0, false) != B_OK) {
+			BOOT_GDT_SEGMENT_COUNT * sizeof(segment_descriptor), 0) != B_OK) {
 		panic("Failed to allocate GDT.\n");
 	}
 
@@ -224,7 +224,7 @@ static void
 arch_mmu_allocate_page_directory(void)
 {
 	if (platform_allocate_region((void **)&sPageDirectory,
-			B_PAGE_SIZE + ALIGN_PAGEDIR, 0, false) != B_OK)
+			B_PAGE_SIZE + ALIGN_PAGEDIR, 0) != B_OK)
 		panic("Failed to allocate page directory.");
 	sPageDirectory = (uint32_t *)ROUNDUP((uint32_t)sPageDirectory, ALIGN_PAGEDIR);
 	memset(sPageDirectory, 0, B_PAGE_SIZE);

src/system/boot/platform/efi/arch/x86/arch_smp.cpp

@@ -242,7 +242,7 @@ arch_smp_init_other_cpus(void)
 		// create a final stack the trampoline code will put the ap processor on
 		void * stack = NULL;
 		const size_t size = KERNEL_STACK_SIZE + KERNEL_STACK_GUARD_PAGES * B_PAGE_SIZE;
-		if (platform_allocate_region(&stack, size, 0, false) != B_OK) {
+		if (platform_allocate_region(&stack, size, 0) != B_OK) {
 			panic("Unable to allocate AP stack");
 		}
 		memset(stack, 0, size);

src/system/boot/platform/efi/arch/x86/arch_start.cpp

@@ -64,7 +64,7 @@ arch_start_kernel(addr_t kernelEntry)
 	// Allocate virtual memory for kernel args
 	struct kernel_args *kernelArgs = NULL;
 	if (platform_allocate_region((void **)&kernelArgs,
-			sizeof(struct kernel_args), 0, false) != B_OK)
+			sizeof(struct kernel_args), 0) != B_OK)
 		panic("Failed to allocate kernel args.");
 
 	addr_t virtKernelArgs;

src/system/boot/platform/efi/arch/x86_64/arch_mmu.cpp

@@ -201,7 +201,7 @@ arch_mmu_generate_post_efi_page_tables(size_t memory_map_size,
 
 	// Allocate the top level PML4.
 	pml4 = NULL;
-	if (platform_allocate_region((void**)&pml4, B_PAGE_SIZE, 0, false) != B_OK)
+	if (platform_allocate_region((void**)&pml4, B_PAGE_SIZE, 0) != B_OK)
 		panic("Failed to allocate PML4.");
 	gKernelArgs.arch_args.phys_pgdir = (uint32_t)(addr_t)pml4;
 	memset(pml4, 0, B_PAGE_SIZE);

src/system/boot/platform/efi/debug.cpp

@@ -87,7 +87,7 @@ allocate_ring_buffer(void)
 	void* buffer = NULL;
 	size_t size = 1024 * 1024;
 
-	if (platform_allocate_region(&buffer, size, 0, false) != B_OK)
+	if (platform_allocate_region(&buffer, size, 0) != B_OK)
 		return;
 
 	sDebugSyslogBuffer = create_ring_buffer_etc(buffer, size, 0);

src/system/boot/platform/efi/mmu.cpp

@@ -42,7 +42,9 @@ struct memory_region {
 };
 
 
-static addr_t sNextVirtualAddress = KERNEL_LOAD_BASE + 32 * 1024 * 1024;
+static const size_t kMaxKernelSize = 0x2000000;		// 32 MB
+static addr_t sNextVirtualAddress = KERNEL_LOAD_BASE + kMaxKernelSize;
+
 static memory_region *allocated_regions = NULL;
 
 
@@ -91,24 +93,14 @@ get_current_virtual_address()
 // addresses to kernel addresses.
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 /* protection */,
-	bool exactAddress)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	TRACE("%s: called\n", __func__);
 
-	efi_physical_addr addr;
 	size_t pages = ROUNDUP(size, B_PAGE_SIZE) / B_PAGE_SIZE;
-	efi_status status;
-
-	if (exactAddress) {
-		addr = (efi_physical_addr)(addr_t)*_address;
-		status = kBootServices->AllocatePages(AllocateAddress,
-			EfiLoaderData, pages, &addr);
-	} else {
-		addr = 0;
-		status = kBootServices->AllocatePages(AllocateAnyPages,
-			EfiLoaderData, pages, &addr);
-	}
+	efi_physical_addr addr = 0;
+	efi_status status = kBootServices->AllocatePages(AllocateAnyPages,
+		EfiLoaderData, pages, &addr);
 
 	if (status != EFI_SUCCESS)
 		return B_NO_MEMORY;
@@ -121,14 +113,9 @@ platform_allocate_region(void **_address, size_t size, uint8 /* protection */,
 
 	memory_region *region = new(std::nothrow) memory_region {
 		next: allocated_regions,
-#ifdef __riscv
-		// Disables allocation at fixed virtual address
 		vaddr: 0,
-#else
-		vaddr: *_address == NULL ? 0 : (addr_t)*_address,
-#endif
 		paddr: (phys_addr_t)addr,
-		size: size
+		size: size,
 	};
 
 	if (region == NULL) {
@@ -136,6 +123,20 @@ platform_allocate_region(void **_address, size_t size, uint8 /* protection */,
 		return B_NO_MEMORY;
 	}
 
+	if (*_address != NULL) {
+		// This is only useful for mapping the kernel itself.
+		// Validate base and size, but don't check for duplicates.
+		addr_t virtualAddress = (addr_t)*_address;
+		if (virtualAddress < KERNEL_LOAD_BASE
+				|| (virtualAddress + size) > (KERNEL_LOAD_BASE + kMaxKernelSize)) {
+			kBootServices->FreePages(addr, pages);
+			delete region;
+			return B_BAD_VALUE;
+		}
+
+		region->vaddr = virtualAddress;
+	}
+
 #ifdef TRACE_MMU
 	//region->dprint("Allocated");
 #endif
@@ -146,11 +147,11 @@ platform_allocate_region(void **_address, size_t size, uint8 /* protection */,
 
 
 extern "C" status_t
-platform_allocate_lomem(void **_address, size_t size)
+platform_allocate_region_below(void **_address, size_t size, phys_addr_t maxAddress)
 {
 	TRACE("%s: called\n", __func__);
 
-	efi_physical_addr addr = KERNEL_LOAD_BASE - B_PAGE_SIZE;
+	efi_physical_addr addr = maxAddress;
 	size_t pages = ROUNDUP(size, B_PAGE_SIZE) / B_PAGE_SIZE;
 	efi_status status = kBootServices->AllocatePages(AllocateMaxAddress,
 		EfiLoaderData, pages, &addr);
@@ -159,7 +160,7 @@ platform_allocate_lomem(void **_address, size_t size)
 
 	memory_region *region = new(std::nothrow) memory_region {
 		next: allocated_regions,
-		vaddr: (addr_t)addr,
+		vaddr: 0,
 		paddr: (phys_addr_t)addr,
 		size: size
 	};
@@ -234,6 +235,29 @@ convert_physical_ranges()
 }
 
 
+extern "C" status_t
+platform_assign_kernel_address_for_region(void *address, addr_t assign)
+{
+	// Double cast needed to avoid sign extension issues on 32-bit architecture
+	phys_addr_t addr = (phys_addr_t)(addr_t)address;
+
+	for (memory_region *region = allocated_regions; region;
+			region = region->next) {
+		if (region->paddr <= addr && addr < region->paddr + region->size) {
+			if (region->paddr != addr)
+				return EINVAL;
+			if (region->vaddr != 0)
+				return EALREADY;
+
+			region->vaddr = assign;
+			return B_OK;
+		}
+	}
+
+	return B_ERROR;
+}
+
+
 extern "C" status_t
 platform_bootloader_address_to_kernel_address(void *address, addr_t *_result)
 {
@@ -249,9 +273,9 @@ platform_bootloader_address_to_kernel_address(void *address, addr_t *_result)
 			region = region->next) {
 		if (region->paddr <= addr && addr < region->paddr + region->size) {
 			// Lazily allocate virtual memory.
-			if (region->vaddr == 0) {
+			if (region->vaddr == 0)
 				region->vaddr = get_next_virtual_address(region->size);
-			}
+
 			*_result = region->vaddr + (addr - region->paddr);
 			//dprintf("Converted bootloader address %p in region %#lx-%#lx to %#lx\n",
 			//	address, region->paddr, region->paddr + region->size, *_result);

src/system/boot/platform/efi/mmu.h

@@ -41,13 +41,16 @@ bool mmu_next_region(void** cookie, addr_t* vaddr, phys_addr_t* paddr, size_t* s
 extern addr_t mmu_map_physical_memory(addr_t physicalAddress, size_t size,
 	uint32 flags);
 
+extern status_t platform_assign_kernel_address_for_region(void *address, addr_t assign);
+
 extern status_t platform_kernel_address_to_bootloader_address(addr_t address,
 	void **_result);
 
 extern status_t platform_bootloader_address_to_kernel_address(void *address,
 	addr_t *_result);
 
-extern status_t platform_allocate_lomem(void **_address, size_t size);
+extern status_t platform_allocate_region_below(void **_address,
+	size_t size, phys_addr_t maxAddress);
 
 #ifdef __cplusplus
 }

src/system/boot/platform/efi/start.cpp

@@ -197,8 +197,7 @@ platform_start_kernel(void)
 	// map in a kernel stack
 	void *stack_address = NULL;
 	if (platform_allocate_region(&stack_address,
-		KERNEL_STACK_SIZE + KERNEL_STACK_GUARD_PAGES * B_PAGE_SIZE, 0, false)
-		!= B_OK) {
+			KERNEL_STACK_SIZE + KERNEL_STACK_GUARD_PAGES * B_PAGE_SIZE, 0) != B_OK) {
 		panic("Unabled to allocate a stack");
 	}
 	gKernelArgs.cpu_kstack[0].start = fix_address((addr_t)stack_address);

src/system/boot/platform/next_m68k/mmu.cpp

@@ -136,8 +136,7 @@ mmu_init(void)
 
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool /*exactAddress*/)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	return B_UNSUPPORTED;
 }

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

@@ -27,7 +27,7 @@ platform_allocate_heap_region(size_t size, void **_base)
 
 	*_base = NULL;
 	status_t error = platform_allocate_region(_base, size,
-		B_READ_AREA | B_WRITE_AREA, false);
+		B_READ_AREA | B_WRITE_AREA);
 	if (error != B_OK)
 		return error;
 

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

@@ -12,14 +12,13 @@
 
 
 status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool exactAddress)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	if (size == 0)
 		return B_BAD_VALUE;
 
 	void *address = arch_mmu_allocate(*_address, size, protection,
-		exactAddress);
+		false);
 	if (address == NULL)
 		return B_NO_MEMORY;
 

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

@@ -433,7 +433,7 @@ TFTP::ReceiveFile(const char* fileName, uint8** data, size_t* size)
 	// allocate memory for the data
 	uint8* fileData = NULL;
 	if (platform_allocate_region((void**)&fileData, fileSize,
-			B_READ_AREA | B_WRITE_AREA, false) != B_OK) {
+			B_READ_AREA | B_WRITE_AREA) != B_OK) {
 		TRACE(("TFTP: allocating memory for file data failed\n"));
 		return B_NO_MEMORY;
 	}

src/system/boot/platform/riscv/mmu.cpp

@@ -297,14 +297,10 @@ GetSatp()
 //	#pragma mark -
 
 extern "C" status_t
-platform_allocate_region(void** address, size_t size, uint8 protection,
-	bool exactAddress)
+platform_allocate_region(void** address, size_t size, uint8 protection)
 {
 	size = ROUNDUP(size, B_PAGE_SIZE);
 
-	if (exactAddress)
-		return B_ERROR;
-
 	ObjectDeleter<MemoryRegion> region(new(std::nothrow) MemoryRegion());
 	if (!region.IsSet())
 		return B_NO_MEMORY;
@@ -417,8 +413,7 @@ mmu_init_for_kernel(addr_t& satp)
 	void* stack_address = NULL;
 	if (platform_allocate_region(&stack_address,
 		KERNEL_STACK_SIZE + KERNEL_STACK_GUARD_PAGES * B_PAGE_SIZE,
-		B_READ_AREA | B_WRITE_AREA, false)
-		!= B_OK) {
+		B_READ_AREA | B_WRITE_AREA) != B_OK) {
 		panic("Unabled to allocate a stack");
 	}
 	gKernelArgs.cpu_kstack[0].start = fix_address((addr_t)stack_address);

src/system/boot/platform/u-boot/arch/ppc/arch_mmu.cpp

@@ -350,8 +350,7 @@ mmu_init(void* fdt)
 
 
 extern "C" status_t
-platform_allocate_region(void **_address, size_t size, uint8 protection,
-	bool /*exactAddress*/)
+platform_allocate_region(void **_address, size_t size, uint8 protection)
 {
 	TRACE(("platform_allocate_region(&%p, %zd)\n", *_address, size));