OpenFirmware now has its own arch subtree. Added most of the code needed

to take over the PPC MMU (and let OF still operate) - there is basically
everything to implement a proper ELF loader now.
Unlike BIOS/IA-32, OpenFirmware is available on a lot of architectures.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@4991 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/boot/platform/openfirmware/Jamfile

@@ -1,7 +1,5 @@
 SubDir OBOS_TOP src kernel boot platform openfirmware ;
 
-SubDirHdrs $(OBOS_TOP) headers private kernel boot platform $(OBOS_BOOT_PLATFORM) ;
-
 KernelMergeObject boot_platform_openfirmware.o :
 #	crt0.S
 	<$(SOURCE_GRIST)>start.c
@@ -17,4 +15,5 @@ KernelMergeObject boot_platform_openfirmware.o :
 
 SEARCH on [ FGristFiles crt0.S ]
     = [ FDirName $(OBOS_TOP) src kernel boot arch $(OBOS_ARCH) ] ;
-	
+
+SubInclude OBOS_TOP src kernel boot platform openfirmware arch ;

src/kernel/boot/platform/openfirmware/arch/Jamfile

@@ -0,0 +1,3 @@
+SubDir OBOS_TOP src kernel boot platform openfirmware arch ;
+
+SubInclude OBOS_TOP src kernel boot platform openfirmware arch $(OBOS_ARCH) ;

src/kernel/boot/platform/openfirmware/arch/ppc/Jamfile

@@ -0,0 +1,13 @@
+SubDir OBOS_TOP src kernel boot platform openfirmware arch ppc ;
+
+SubDirHdrs $(OBOS_TOP) src kernel boot platform $(OBOS_BOOT_PLATFORM) ;
+
+KernelStaticLibrary boot_platform_openfirmware_ppc :
+	arch_mmu.cpp
+	arch_cpu_asm.S
+	mmu.cpp
+	:
+	;
+
+SEARCH on [ FGristFiles arch_cpu_asm.S arch_mmu.cpp ]
+    = [ FDirName $(OBOS_TOP) src kernel core arch $(OBOS_ARCH) ] ;

src/kernel/boot/platform/openfirmware/arch/ppc/mmu.cpp

@@ -0,0 +1,470 @@
+/*
+** Copyright 2003, Axel Dörfler, [email protected]. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+
+
+#include "openfirmware.h"
+
+#include <platform_arch.h>
+#include <boot/stage2.h>
+#include <boot/stdio.h>
+#include <arch_cpu.h>
+#include <arch_mmu.h>
+#include <kernel.h>
+
+#include <OS.h>
+
+
+page_table_entry_group *sPageTable;
+uint32 sPageTableHashMask;
+
+
+static status_t
+insert_memory_range(address_range *ranges, uint32 &numRanges, uint32 maxRanges,
+	const void *start, uint32 size)
+{
+	size = ROUNDUP(size, B_PAGE_SIZE);
+
+	for (uint32 i = 0; i < numRanges; i++) {
+		if ((uint32)start == ranges[i].start + ranges[i].size) {
+			// append to the existing range
+			ranges[i].size += size;
+			return B_OK;
+		} else if ((uint32)start + size == ranges[i].start) {
+			// preprend before the existing range
+			ranges[i].start = (uint32)start;
+			return B_OK;
+		}
+	}
+
+	// no range matched, we need to create a new one
+	
+	if (numRanges >= maxRanges)
+		return B_ENTRY_NOT_FOUND;
+
+	ranges[numRanges].start = (uint32)start;
+	ranges[numRanges].size = size;
+	numRanges++;
+
+	return B_OK;
+}
+
+
+static status_t
+insert_physical_memory_range(void *start, uint32 size)
+{
+	return insert_memory_range(gKernelArgs.physical_memory_range, 
+				gKernelArgs.num_physical_memory_ranges, MAX_PHYSICAL_MEMORY_RANGE,
+				start, size);
+}
+
+
+static status_t
+insert_physical_allocated_range(void *start, uint32 size)
+{
+	return insert_memory_range(gKernelArgs.physical_allocated_range, 
+				gKernelArgs.num_physical_allocated_ranges, MAX_PHYSICAL_ALLOCATED_RANGE,
+				start, size);
+}
+
+
+static status_t
+insert_virtual_allocated_range(void *start, uint32 size)
+{
+	return insert_memory_range(gKernelArgs.virtual_allocated_range, 
+				gKernelArgs.num_virtual_allocated_ranges, MAX_VIRTUAL_ALLOCATED_RANGE,
+				start, size);
+}
+
+
+static status_t
+find_physical_memory_ranges(size_t &total)
+{
+	int memory;
+	if (of_getprop(gChosen, "memory", &memory, sizeof(int)) == OF_FAILED)
+		return B_ERROR;
+	memory = of_instance_to_package(memory);
+
+	total = 0;
+
+	struct of_region regions[64];
+	int count = of_getprop(memory, "reg", regions, sizeof(regions));
+	if (count == OF_FAILED)
+		return B_ERROR;
+	count /= sizeof(of_region);
+
+	for (int32 i = 0; i < count; i++) {
+		if (regions[i].size <= 0) {
+			printf("%ld: empty region", i);
+			continue;
+		}
+		printf("%ld: base = %p, size = %lu\n", i, regions[i].base, regions[i].size);
+
+		total += regions[i].size;
+
+		if (insert_physical_memory_range(regions[i].base, regions[i].size) < B_OK) {
+			printf("cannot map physical memory range (num ranges = %lu)!\n", gKernelArgs.num_physical_memory_ranges);
+			return B_ERROR;
+		}
+	}
+
+	return B_OK;
+}
+
+
+static bool
+is_in_range(address_range *ranges, uint32 numRanges, void *address, size_t size)
+{
+	uint32 start = (uint32)address;
+	uint32 end = start + size;
+
+	for (uint32 i = 0; i < numRanges; i++) {
+		uint32 rangeStart = ranges[i].start;
+		uint32 rangeEnd = rangeStart + ranges[i].size;
+
+		if ((start >= rangeStart && start < rangeEnd)
+			|| (end >= rangeStart && end < rangeEnd))
+			return true;
+	}
+	return false;
+}
+
+
+static bool
+is_virtual_allocated(void *address, size_t size)
+{
+	return is_in_range(gKernelArgs.virtual_allocated_range, 
+				gKernelArgs.num_virtual_allocated_ranges, 
+				address, size);
+}
+
+
+static bool
+is_physical_allocated(void *address, size_t size)
+{
+	return is_in_range(gKernelArgs.physical_allocated_range, 
+				gKernelArgs.num_physical_allocated_ranges, 
+				address, size);
+}
+
+
+static bool
+is_physical_memory(void *address, size_t size)
+{
+	return is_in_range(gKernelArgs.physical_memory_range, 
+				gKernelArgs.num_physical_memory_ranges, 
+				address, size);
+}
+
+
+static bool
+is_physical_memory(void *address)
+{
+	return is_physical_memory(address, 0);
+}
+
+
+static void
+fill_page_table_entry(page_table_entry *entry, uint32 virtualSegmentID, void *virtualAddress, void *physicalAddress, uint8 mode, bool secondaryHash)
+{
+	// lower 32 bit - set at once
+	((uint32 *)entry)[1] = (((uint32)physicalAddress / B_PAGE_SIZE) << 12) | mode;
+	/*entry->physical_page_number = (uint32)physicalAddress / B_PAGE_SIZE;
+	entry->_reserved0 = 0;
+	entry->referenced = false;
+	entry->changed = false;
+	entry->write_through = (mode >> 6) & 1;
+	entry->caching_inhibited = (mode >> 5) & 1;
+	entry->memory_coherent = (mode >> 4) & 1;
+	entry->guarded = (mode >> 3) & 1;
+	entry->_reserved1 = 0;
+	entry->page_protection = mode & 0x3;*/
+	eieio();
+		// we need to make sure that the lower 32 bit were
+		// already written when the entry becomes valid
+
+	// upper 32 bit
+	entry->virtual_segment_id = virtualSegmentID;
+	entry->hash = secondaryHash;
+	entry->abbr_page_index = ((uint32)virtualAddress >> 22) & 0x3f;
+	entry->valid = true;
+}
+
+
+static void
+map_page(void *virtualAddress, void *physicalAddress, uint8 mode)
+{
+	uint32 virtualSegmentID = get_sr(virtualAddress) & 0xffffff;
+
+	uint32 hash = page_table_entry::PrimaryHash(virtualSegmentID, (uint32)virtualAddress);
+	page_table_entry_group *group = &sPageTable[hash & sPageTableHashMask];
+
+	for (int32 i = 0; i < 8; i++) {
+		// 8 entries in a group
+		if (group->entry[i].valid)
+			continue;
+
+		fill_page_table_entry(&group->entry[i], virtualSegmentID, virtualAddress, physicalAddress, mode, false);
+		return;
+	}
+
+	hash = page_table_entry::SecondaryHash(hash);
+	group = &sPageTable[hash & sPageTableHashMask];
+
+	for (int32 i = 0; i < 8; i++) {
+		if (group->entry[i].valid)
+			continue;
+
+		fill_page_table_entry(&group->entry[i], virtualSegmentID, virtualAddress, physicalAddress, mode, true);
+		return;
+	}
+}
+
+
+static void
+map_range(void *virtualAddress, void *physicalAddress, size_t size, uint8 mode)
+{
+	for (uint32 offset = 0; offset < size; offset += B_PAGE_SIZE) {
+		map_page((void *)(uint32(virtualAddress) + offset), 
+			(void *)(uint32(physicalAddress) + offset), mode);
+	}
+}
+
+
+static status_t
+find_allocated_ranges(void *pageTable, void **_physicalPageTable)
+{
+	// we have to preserve the OpenFirmware established mappings
+	// if we want to continue to use its service after we've
+	// taken over (we will probably need less translations once
+	// we have proper driver support for the target hardware).
+	int mmu;
+	if (of_getprop(gChosen, "mmu", &mmu, sizeof(int)) == OF_FAILED)
+		return B_ERROR;
+	mmu = of_instance_to_package(mmu);
+
+	struct translation_map {
+		void	*virtual_address;
+		int		length;
+		void	*physical_address;
+		int		mode;
+	} translations[64];
+	int length = of_getprop(mmu, "translations", &translations, sizeof(translations));
+	if (length == OF_FAILED)
+		printf("getting translations failed\n");
+	length = length / sizeof(struct translation_map);
+	uint32 total = 0;
+	printf("found %d translations\n", length);
+
+	for (int i = 0; i < length; i++) {
+		struct translation_map *map = &translations[i];
+		//printf("%i: map: %p, length %d -> physical: %p, mode %d\n", i, map->virtual_address, map->length, map->physical_address, map->mode);
+
+		// insert range in physical allocated, if it points to physical memory
+
+		if (is_physical_memory(map->physical_address)
+			&& insert_physical_allocated_range(map->physical_address,
+					map->length) < B_OK) {
+			printf("cannot map physical allocated range (num ranges = %lu)!\n", gKernelArgs.num_physical_allocated_ranges);
+			return B_ERROR;
+		}
+
+		if (map->virtual_address == pageTable) {
+			puts("found page table!");
+			*_physicalPageTable = map->physical_address;
+		}
+
+		// insert range in virtual allocated
+
+		if (insert_virtual_allocated_range(map->virtual_address,
+				map->length) < B_OK) {
+			printf("cannot map virtual allocated range (num ranges = %lu)!\n", gKernelArgs.num_virtual_allocated_ranges);
+		}
+
+		// map range into the page table
+
+		map_range(map->virtual_address, map->physical_address, map->length, map->mode);
+
+		total += map->length;
+	}
+	//printf("total mapped: %lu\n", total);
+
+	return B_OK;
+}
+
+
+/** Computes the recommended minimal page table size as
+ *	described in table 7-22 of the PowerPC "Programming
+ *	Environment for 32-Bit Microprocessors".
+ *	The page table size ranges from 64 kB (for 8 MB RAM)
+ *	to 32 MB (for 4 GB RAM).
+ */
+
+static size_t
+suggested_page_table_size(size_t total)
+{
+	uint32 max = 23;	
+		// 2^23 == 8 MB
+
+	while (max < 32) {
+		if (total <= (1UL << max))
+			break;
+
+		max++;
+	}
+
+	return 1UL << (max - 7);
+		// 2^(23 - 7) == 64 kB
+}
+
+
+static void *
+find_physical_memory_range(size_t size)
+{
+	for (uint32 i = 0; i < gKernelArgs.num_physical_memory_ranges; i++) {
+		if (gKernelArgs.physical_memory_range[i].size > size)
+			return (void *)gKernelArgs.physical_memory_range[i].start;
+	}
+	return NULL;
+}
+
+
+static void *
+find_free_physical_range(size_t size)
+{
+	// just do a simple linear search at the end of the allocated
+	// ranges (dumb memory allocation)
+	if (gKernelArgs.num_physical_allocated_ranges == 0) {
+		if (gKernelArgs.num_physical_memory_ranges == 0)
+			return NULL;
+
+		return find_physical_memory_range(size);
+	}
+
+	for (uint32 i = 0; i < gKernelArgs.num_physical_allocated_ranges; i++) {
+		void *address = (void *)(gKernelArgs.physical_allocated_range[i].start + gKernelArgs.physical_allocated_range[i].size);
+		if (!is_physical_allocated(address, size) && is_physical_memory(address, size))
+			return address;
+	}
+	return NULL;
+}
+
+
+static void *
+find_free_virtual_range(size_t size)
+{
+	for (uint32 i = 0; i < gKernelArgs.num_virtual_allocated_ranges; i++) {
+		void *address = (void *)(gKernelArgs.virtual_allocated_range[i].start + gKernelArgs.virtual_allocated_range[i].size);
+		if (!is_virtual_allocated(address, size))
+			return address;
+	}
+	return NULL;
+}
+
+
+extern "C" void *
+arch_mmu_alloc_at(void *virtualAddress, size_t size, uint8 protection)
+{
+	// we only know page sizes
+	size = ROUNDUP(size, B_PAGE_SIZE);
+
+	// set protection to WIMGxPP: -I--xPP
+	if (protection & B_WRITE_AREA)
+		protection = 0x23;
+	else
+		protection = 0x21;
+
+	if (virtualAddress == NULL) {
+		// find free address large enough to hold "size"
+		virtualAddress = find_free_virtual_range(size);
+		if (virtualAddress == NULL)
+			return NULL;
+	} else {
+		if (is_virtual_allocated(virtualAddress, size))
+			return NULL;
+	}
+
+	// we have a free virtual range for the allocation, now
+	// have a look for free physical memory as well (we assume
+	// that a) there is enough memory, and b) failing is fatal
+	// so that we don't have to optimize for these cases :)
+	
+	void *physicalAddress = find_free_physical_range(size);
+	if (physicalAddress == NULL)
+		return NULL;
+
+	// everything went fine, so lets mark the space as used.
+
+printf("mmu_alloc: va %p, pa %p, size %u\n", virtualAddress, physicalAddress, size);
+	insert_virtual_allocated_range(virtualAddress, size);
+	insert_physical_allocated_range(physicalAddress, size);
+
+	map_range(virtualAddress, physicalAddress, size, protection);
+
+	return virtualAddress;
+}
+
+
+extern "C" void *
+arch_mmu_alloc(size_t size, uint8 protection)
+{
+	return arch_mmu_alloc_at(NULL, size, protection);
+}
+
+
+extern "C" status_t
+arch_mmu_init(void)
+{
+	// get map of physical memory (fill in kernel_args structure)
+	
+	size_t total;
+	if (find_physical_memory_ranges(total) < B_OK)
+		return B_ERROR;
+	printf("total physical memory = %u MB\n", total / (1024*1024));
+
+	// get OpenFirmware's current page table
+
+	void *table;
+	size_t tableSize;
+	ppc_get_page_table(&table, &tableSize);
+	printf("-> table = %p, size = %u\n", table, tableSize);
+	if (table == NULL && tableSize == 0) {
+		puts("OpenFirmware is in real addressing mode!");
+	}
+
+	// can we just keep the page table?
+	size_t suggestedTableSize = suggested_page_table_size(total);
+	printf("suggested page table size = %u\n", suggestedTableSize);
+	if (tableSize < suggestedTableSize) {
+		// nah, we need a new one!
+		printf("need new page table, size = %u!\n", suggestedTableSize);
+		table = of_claim(0, suggestedTableSize, suggestedTableSize);
+			// KERNEL_BASE would be better as virtual address, but
+			// at least with Apple's OpenFirmware, it makes no
+			// difference - we will have to remap it later
+		if (table == (void *)OF_FAILED)
+			return B_NO_MEMORY;
+		printf("new table at: %p\n", table);
+		sPageTable = (page_table_entry_group *)table;
+		sPageTableHashMask = (suggestedTableSize >> 6) - 1;
+	} else {
+		// ToDo: we could check if the page table is much too large
+		//	and create a smaller one in this case (in order to save 
+		//	memory).
+		sPageTable = (page_table_entry_group *)table;
+		sPageTableHashMask = (tableSize >> 6) - 1;
+	}
+
+	// find already allocated ranges of physical memory
+	// and the virtual address space
+
+	void *physicalTable;
+	if (find_allocated_ranges(table, &physicalTable) < B_OK)
+		return B_ERROR;
+
+	// ToDo: take over control of MMU
+
+	return B_OK;
+}
+

src/kernel/boot/platform/openfirmware/start.c

@@ -4,7 +4,7 @@
 */
 
 
-#include <SupportDefs.h>
+#include <OS.h>
 #include <boot/stage2.h>
 #include <boot/heap.h>
 #include <platform_arch.h>
@@ -69,7 +69,8 @@ start(void *openFirmwareEntry)
 
 	of_init(openFirmwareEntry);
 	console_init();
-	//arch_mmu_init();
+	arch_mmu_init();
+	printf("testing mmu allocation: %p\n", arch_mmu_alloc(128 * 1024, B_READ_AREA));
 
 	main(&args);
 		// if everything wents fine, main() never returns