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[VFS] Add some STFS magic numbers, skip hash table checks for read only packages

This commit is contained in:
emoose 2020-01-11 10:46:09 +00:00 committed by illusion
parent 428f554cf3
commit 0553575ee1
2 changed files with 65 additions and 49 deletions
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108
src/xenia/vfs/devices/stfs_container_device.cc
View File

@ -600,11 +600,15 @@ size_t StfsContainerDevice::BlockToOffsetSTFS(uint64_t block_index) {
num_tables++;
}
uint64_t dataBlock = block_index + num_tables * ((block_index + 0xAA) / 0xAA);
if (block_index >= 170) {
dataBlock += num_tables * ((block_index + 0x70E4) / 0x70E4);
if (block_index >= 28900) {
dataBlock += num_tables * ((block_index + 0x4AF768) / 0x4AF768);
uint64_t dataBlock =
block_index + num_tables * ((block_index + kSTFSBlocksPerHashTable) /
kSTFSBlocksPerHashTable);
if (block_index >= kSTFSBlocksPerHashTable) {
dataBlock += num_tables * ((block_index + kSTFSBlocksPerL1HashTable) /
kSTFSBlocksPerL1HashTable);
if (block_index >= kSTFSBlocksPerL1HashTable) {
dataBlock += num_tables * ((block_index + kSTFSBlocksPerL2HashTable) /
kSTFSBlocksPerL2HashTable);
}
}
@ -624,7 +628,7 @@ size_t StfsContainerDevice::BlockToOffsetSTFS_Old(uint64_t block_index) {
// Level 1: hash table of next 170 hash tables
// Level 2: hash table of next 170 level 1 hash tables
// And so on...
uint64_t base = kSTFSHashSpacing;
uint64_t base = kSTFSBlocksPerHashTable;
block = block_index;
for (uint32_t i = 0; i < 3; i++) {
block += (block_index + (base << block_shift)) / (base << block_shift);
@ -632,7 +636,7 @@ size_t StfsContainerDevice::BlockToOffsetSTFS_Old(uint64_t block_index) {
break;
}
base *= kSTFSHashSpacing;
base *= kSTFSBlocksPerHashTable;
}
return xe::round_up(header_.header_size, 0x1000) + (block << 12);
@ -644,53 +648,53 @@ size_t StfsContainerDevice::BackingBlockToOffsetSTFS(uint64_t backing_block) {
size_t StfsContainerDevice::BlockToHashBlockOffset(uint64_t block,
uint32_t hash_level) {
uint32_t numTables = 1;
uint32_t blockStep0 = 0xAB;
uint32_t blockStep1 = 0x718F;
uint32_t num_tables = 1;
uint32_t block_step0 = 0xAB;
uint32_t block_step1 = 0x718F;
if (!read_only_package()) {
numTables = 2;
blockStep0 = 0xAC;
blockStep1 = 0x723A;
num_tables = 2;
block_step0 = 0xAC;
block_step1 = 0x723A;
}
uint64_t backing_num = 0;
switch (hash_level) {
case 0:
backing_num = (block / 0xAA) * blockStep0;
if (block / 0xAA == 0) {
backing_num = (block / kSTFSBlocksPerHashTable) * block_step0;
if (block / kSTFSBlocksPerHashTable == 0) {
return BackingBlockToOffsetSTFS(backing_num);
}
backing_num += ((block / 0x70E4) + 1) * numTables;
if (block / 0x70E4 == 0) {
backing_num += ((block / kSTFSBlocksPerL1HashTable) + 1) * num_tables;
if (block / kSTFSBlocksPerL1HashTable == 0) {
return BackingBlockToOffsetSTFS(backing_num);
}
break;
case 1:
backing_num = (block / 0x70E4) * blockStep1;
if (block / 0x70E4 == 0) {
return BackingBlockToOffsetSTFS(backing_num + blockStep0);
backing_num = (block / kSTFSBlocksPerL1HashTable) * block_step1;
if (block / kSTFSBlocksPerL1HashTable == 0) {
return BackingBlockToOffsetSTFS(backing_num + block_step0);
}
break;
default:
return BackingBlockToOffsetSTFS(blockStep1);
return BackingBlockToOffsetSTFS(block_step1);
}
return BackingBlockToOffsetSTFS(backing_num + numTables);
return BackingBlockToOffsetSTFS(backing_num + num_tables);
}
StfsContainerDevice::BlockHash StfsContainerDevice::GetHashEntry(
const uint8_t* map_ptr, uint32_t block_index, uint32_t level,
uint32_t table_offset) {
bool secondary_table) {
uint32_t record = block_index;
for (uint32_t i = 0; i < level; i++) {
record = record / 0xAA;
record = record / kSTFSBlocksPerHashTable;
}
record = record % 0xAA;
record = record % kSTFSBlocksPerHashTable;
size_t hash_offset = BlockToHashBlockOffset(block_index, level);
if (table_offset != 0) {
hash_offset += 0x1000; // use alternate hash table?
if (secondary_table) {
hash_offset += bytes_per_sector(); // use alternate hash table?
}
const uint8_t* hash_data = map_ptr + hash_offset;
@ -703,32 +707,42 @@ StfsContainerDevice::BlockHash StfsContainerDevice::GetHashEntry(
StfsContainerDevice::BlockHash StfsContainerDevice::GetBlockHash(
const uint8_t* map_ptr, uint32_t block_index) {
uint32_t table_offset = 0;
// Check RootActiveIndex flag - increment table_offset to use for root table
// if set
bool use_secondary_table = false;
// Use secondary table for root table if RootActiveIndex flag is set
if (header_.stfs_volume_descriptor.flags & 2) {
table_offset = 1;
use_secondary_table = true;
}
if (header_.stfs_volume_descriptor.total_allocated_block_count >= 0x70E4) {
// Get the L2 entry for the block
auto l2_entry = GetHashEntry(map_ptr, block_index, 2, table_offset);
table_offset = 0;
if (l2_entry.info & 0x40) { // ActiveIndex flag
table_offset = 1;
// Check upper hash table levels to find which table (primary/secondary) to
// use.
// Hopefully we can skip doing this if the package is read-only
// (and RootActiveIndex isn't set)
if (!read_only_package() || use_secondary_table) {
auto num_blocks =
header_.stfs_volume_descriptor.total_allocated_block_count;
if (num_blocks >= kSTFSBlocksPerL1HashTable) {
// Get the L2 entry for the block
auto l2_entry =
GetHashEntry(map_ptr, block_index, 2, use_secondary_table);
use_secondary_table = false;
if (l2_entry.info & 0x40) { // ActiveIndex flag
use_secondary_table = true;
}
}
if (num_blocks >= kSTFSBlocksPerHashTable) {
// Get the L1 entry for this block
auto l1_entry =
GetHashEntry(map_ptr, block_index, 1, use_secondary_table);
use_secondary_table = false;
if (l1_entry.info & 0x40) { // ActiveIndex flag
use_secondary_table = true;
}
}
}
if (header_.stfs_volume_descriptor.total_allocated_block_count >= 0xAA) {
// Get the L1 entry for this block
auto l1Entry = GetHashEntry(map_ptr, block_index, 1, table_offset);
table_offset = 0;
if (l1Entry.info & 0x40) { // ActiveIndex flag
table_offset = 1;
}
}
return GetHashEntry(map_ptr, block_index, 0, table_offset);
return GetHashEntry(map_ptr, block_index, 0, use_secondary_table);
}
bool StfsVolumeDescriptor::Read(const uint8_t* p) {

6
src/xenia/vfs/devices/stfs_container_device.h
View File

@ -205,7 +205,9 @@ class StfsContainerDevice : public Device {
uint32_t info;
};
const uint32_t kSTFSHashSpacing = 170;
const uint32_t kSTFSBlocksPerHashTable = 0xAA;
const uint32_t kSTFSBlocksPerL1HashTable = 0x70E4;
const uint32_t kSTFSBlocksPerL2HashTable = 0x4AF768;
bool ResolveFromFolder(const std::wstring& path);
@ -228,7 +230,7 @@ class StfsContainerDevice : public Device {
size_t BlockToHashBlockOffset(uint64_t block, uint32_t hash_level = 0);
BlockHash GetHashEntry(const uint8_t* map_ptr, uint32_t block_index,
uint32_t level, uint32_t table_offset);
uint32_t level, bool secondary_table = false);
BlockHash GetBlockHash(const uint8_t* map_ptr, uint32_t block_index);