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audk/FatPkg/FatPei/FatLiteAccess.c

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/** @file
FAT file system access routines for FAT recovery PEIM
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "FatLitePeim.h"
/**
Check if there is a valid FAT in the corresponding Block device
of the volume and if yes, fill in the relevant fields for the
volume structure. Note there should be a valid Block device number
already set.
@param PrivateData Global memory map for accessing global
variables.
@param Volume On input, the BlockDeviceNumber field of the
Volume should be a valid value. On successful
output, all fields except the VolumeNumber
field is initialized.
@retval EFI_SUCCESS A FAT is found and the volume structure is
initialized.
@retval EFI_NOT_FOUND There is no FAT on the corresponding device.
@retval EFI_DEVICE_ERROR There is something error while accessing device.
**/
EFI_STATUS
FatGetBpbInfo (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN OUT PEI_FAT_VOLUME *Volume
)
{
EFI_STATUS Status;
PEI_FAT_BOOT_SECTOR Bpb;
PEI_FAT_BOOT_SECTOR_EX BpbEx;
UINT32 Sectors;
UINT32 SectorsPerFat;
UINT32 RootDirSectors;
UINT64 FatLba;
UINT64 RootLba;
UINT64 FirstClusterLba;
//
// Read in the BPB
//
Status = FatReadDisk (
PrivateData,
Volume->BlockDeviceNo,
0,
sizeof (PEI_FAT_BOOT_SECTOR_EX),
&BpbEx
);
if (EFI_ERROR (Status)) {
return Status;
}
CopyMem (
(UINT8 *) (&Bpb),
(UINT8 *) (&BpbEx),
sizeof (PEI_FAT_BOOT_SECTOR)
);
Volume->FatType = FatUnknown;
Sectors = Bpb.Sectors;
if (Sectors == 0) {
Sectors = Bpb.LargeSectors;
}
SectorsPerFat = Bpb.SectorsPerFat;
if (SectorsPerFat == 0) {
SectorsPerFat = BpbEx.LargeSectorsPerFat;
Volume->FatType = Fat32;
}
//
// Filter out those not a FAT
//
if (Bpb.Ia32Jump[0] != 0xe9 && Bpb.Ia32Jump[0] != 0xeb && Bpb.Ia32Jump[0] != 0x49) {
return EFI_NOT_FOUND;
}
if (Bpb.ReservedSectors == 0 || Bpb.NoFats == 0 || Sectors == 0) {
return EFI_NOT_FOUND;
}
if (Bpb.SectorsPerCluster != 1 &&
Bpb.SectorsPerCluster != 2 &&
Bpb.SectorsPerCluster != 4 &&
Bpb.SectorsPerCluster != 8 &&
Bpb.SectorsPerCluster != 16 &&
Bpb.SectorsPerCluster != 32 &&
Bpb.SectorsPerCluster != 64 &&
Bpb.SectorsPerCluster != 128
) {
return EFI_NOT_FOUND;
}
if (Volume->FatType == Fat32 && (SectorsPerFat == 0 || BpbEx.FsVersion != 0)) {
return EFI_NOT_FOUND;
}
if (Bpb.Media != 0xf0 &&
Bpb.Media != 0xf8 &&
Bpb.Media != 0xf9 &&
Bpb.Media != 0xfb &&
Bpb.Media != 0xfc &&
Bpb.Media != 0xfd &&
Bpb.Media != 0xfe &&
Bpb.Media != 0xff &&
//
// FujitsuFMR
//
Bpb.Media != 0x00 &&
Bpb.Media != 0x01 &&
Bpb.Media != 0xfa
) {
return EFI_NOT_FOUND;
}
if (Volume->FatType != Fat32 && Bpb.RootEntries == 0) {
return EFI_NOT_FOUND;
}
//
// If this is fat32, refuse to mount mirror-disabled volumes
//
if (Volume->FatType == Fat32 && ((BpbEx.ExtendedFlags & 0x80) != 0)) {
return EFI_NOT_FOUND;
}
//
// Fill in the volume structure fields
// (Sectors & SectorsPerFat is computed earlier already)
//
Volume->ClusterSize = Bpb.SectorSize * Bpb.SectorsPerCluster;
Volume->RootEntries = Bpb.RootEntries;
Volume->SectorSize = Bpb.SectorSize;
RootDirSectors = ((Volume->RootEntries * sizeof (FAT_DIRECTORY_ENTRY)) + (Volume->SectorSize - 1)) / Volume->SectorSize;
FatLba = Bpb.ReservedSectors;
RootLba = Bpb.NoFats * SectorsPerFat + FatLba;
FirstClusterLba = RootLba + RootDirSectors;
Volume->VolumeSize = MultU64x32 (Sectors, Volume->SectorSize);
Volume->FatPos = MultU64x32 (FatLba, Volume->SectorSize);
Volume->RootDirPos = MultU64x32 (RootLba, Volume->SectorSize);
Volume->FirstClusterPos = MultU64x32 (FirstClusterLba, Volume->SectorSize);
Volume->MaxCluster = (UINT32) (Sectors - FirstClusterLba) / Bpb.SectorsPerCluster;
Volume->RootDirCluster = BpbEx.RootDirFirstCluster;
//
// If this is not a fat32, determine if it's a fat16 or fat12
//
if (Volume->FatType != Fat32) {
if (Volume->MaxCluster >= 65525) {
return EFI_NOT_FOUND;
}
Volume->FatType = Volume->MaxCluster < 4085 ? Fat12 : Fat16;
}
return EFI_SUCCESS;
}
/**
Gets the next cluster in the cluster chain
@param PrivateData Global memory map for accessing global variables
@param Volume The volume
@param Cluster The cluster
@param NextCluster The cluster number of the next cluster
@retval EFI_SUCCESS The address is got
@retval EFI_INVALID_PARAMETER ClusterNo exceeds the MaxCluster of the volume.
@retval EFI_DEVICE_ERROR Read disk error
**/
EFI_STATUS
FatGetNextCluster (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN PEI_FAT_VOLUME *Volume,
IN UINT32 Cluster,
OUT UINT32 *NextCluster
)
{
EFI_STATUS Status;
UINT64 FatEntryPos;
UINT32 Dummy;
*NextCluster = 0;
if (Volume->FatType == Fat32) {
FatEntryPos = Volume->FatPos + MultU64x32 (4, Cluster);
Status = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 4, NextCluster);
*NextCluster &= 0x0fffffff;
//
// Pad high bits for our FAT_CLUSTER_... macro definitions to work
//
if ((*NextCluster) >= 0x0ffffff7) {
*NextCluster |= (-1 &~0xf);
}
} else if (Volume->FatType == Fat16) {
FatEntryPos = Volume->FatPos + MultU64x32 (2, Cluster);
Status = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 2, NextCluster);
//
// Pad high bits for our FAT_CLUSTER_... macro definitions to work
//
if ((*NextCluster) >= 0xfff7) {
*NextCluster |= (-1 &~0xf);
}
} else {
FatEntryPos = Volume->FatPos + DivU64x32Remainder (MultU64x32 (3, Cluster), 2, &Dummy);
Status = FatReadDisk (PrivateData, Volume->BlockDeviceNo, FatEntryPos, 2, NextCluster);
if ((Cluster & 0x01) != 0) {
*NextCluster = (*NextCluster) >> 4;
} else {
*NextCluster = (*NextCluster) & 0x0fff;
}
//
// Pad high bits for our FAT_CLUSTER_... macro definitions to work
//
if ((*NextCluster) >= 0x0ff7) {
*NextCluster |= (-1 &~0xf);
}
}
if (EFI_ERROR (Status)) {
return EFI_DEVICE_ERROR;
}
return EFI_SUCCESS;
}
/**
Set a file's CurrentPos and CurrentCluster, then compute StraightReadAmount.
@param PrivateData the global memory map
@param File the file
@param Pos the Position which is offset from the file's
CurrentPos
@retval EFI_SUCCESS Success.
@retval EFI_INVALID_PARAMETER Pos is beyond file's size.
@retval EFI_DEVICE_ERROR Something error while accessing media.
**/
EFI_STATUS
FatSetFilePos (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN PEI_FAT_FILE *File,
IN UINT32 Pos
)
{
EFI_STATUS Status;
UINT32 AlignedPos;
UINT32 Offset;
UINT32 Cluster;
UINT32 PrevCluster;
if (File->IsFixedRootDir) {
if (Pos >= MultU64x32 (File->Volume->RootEntries, 32) - File->CurrentPos) {
return EFI_INVALID_PARAMETER;
}
File->CurrentPos += Pos;
File->StraightReadAmount = (UINT32) (MultU64x32 (File->Volume->RootEntries, 32) - File->CurrentPos);
} else {
DivU64x32Remainder (File->CurrentPos, File->Volume->ClusterSize, &Offset);
AlignedPos = (UINT32) File->CurrentPos - (UINT32) Offset;
while
(
!FAT_CLUSTER_FUNCTIONAL (File->CurrentCluster) &&
AlignedPos + File->Volume->ClusterSize <= File->CurrentPos + Pos
) {
AlignedPos += File->Volume->ClusterSize;
Status = FatGetNextCluster (
PrivateData,
File->Volume,
File->CurrentCluster,
&File->CurrentCluster
);
if (EFI_ERROR (Status)) {
return EFI_DEVICE_ERROR;
}
}
if (FAT_CLUSTER_FUNCTIONAL (File->CurrentCluster)) {
return EFI_INVALID_PARAMETER;
}
File->CurrentPos += Pos;
//
// Calculate the amount of consecutive cluster occupied by the file.
// FatReadFile() will use it to read these blocks once.
//
File->StraightReadAmount = 0;
Cluster = File->CurrentCluster;
while (!FAT_CLUSTER_FUNCTIONAL (Cluster)) {
File->StraightReadAmount += File->Volume->ClusterSize;
PrevCluster = Cluster;
Status = FatGetNextCluster (PrivateData, File->Volume, Cluster, &Cluster);
if (EFI_ERROR (Status)) {
return EFI_DEVICE_ERROR;
}
if (Cluster != PrevCluster + 1) {
break;
}
}
DivU64x32Remainder (File->CurrentPos, File->Volume->ClusterSize, &Offset);
File->StraightReadAmount -= (UINT32) Offset;
}
return EFI_SUCCESS;
}
/**
Reads file data. Updates the file's CurrentPos.
@param PrivateData Global memory map for accessing global variables
@param File The file.
@param Size The amount of data to read.
@param Buffer The buffer storing the data.
@retval EFI_SUCCESS The data is read.
@retval EFI_INVALID_PARAMETER File is invalid.
@retval EFI_DEVICE_ERROR Something error while accessing media.
**/
EFI_STATUS
FatReadFile (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN PEI_FAT_FILE *File,
IN UINTN Size,
OUT VOID *Buffer
)
{
EFI_STATUS Status;
CHAR8 *BufferPtr;
UINT32 Offset;
UINT64 PhysicalAddr;
UINTN Amount;
BufferPtr = Buffer;
if (File->IsFixedRootDir) {
//
// This is the fixed root dir in FAT12 and FAT16
//
if (File->CurrentPos + Size > File->Volume->RootEntries * sizeof (FAT_DIRECTORY_ENTRY)) {
return EFI_INVALID_PARAMETER;
}
Status = FatReadDisk (
PrivateData,
File->Volume->BlockDeviceNo,
File->Volume->RootDirPos + File->CurrentPos,
Size,
Buffer
);
File->CurrentPos += (UINT32) Size;
return Status;
} else {
if ((File->Attributes & FAT_ATTR_DIRECTORY) == 0) {
Size = Size < (File->FileSize - File->CurrentPos) ? Size : (File->FileSize - File->CurrentPos);
}
//
// This is a normal cluster based file
//
while (Size != 0) {
DivU64x32Remainder (File->CurrentPos, File->Volume->ClusterSize, &Offset);
PhysicalAddr = File->Volume->FirstClusterPos + MultU64x32 (File->Volume->ClusterSize, File->CurrentCluster - 2);
Amount = File->StraightReadAmount;
Amount = Size > Amount ? Amount : Size;
Status = FatReadDisk (
PrivateData,
File->Volume->BlockDeviceNo,
PhysicalAddr + Offset,
Amount,
BufferPtr
);
if (EFI_ERROR (Status)) {
return EFI_DEVICE_ERROR;
}
//
// Advance the file's current pos and current cluster
//
FatSetFilePos (PrivateData, File, (UINT32) Amount);
BufferPtr += Amount;
Size -= Amount;
}
return EFI_SUCCESS;
}
}
/**
This function reads the next item in the parent directory and
initializes the output parameter SubFile (CurrentPos is initialized to 0).
The function updates the CurrentPos of the parent dir to after the item read.
If no more items were found, the function returns EFI_NOT_FOUND.
@param PrivateData Global memory map for accessing global variables
@param ParentDir The parent directory.
@param SubFile The File structure containing the sub file that
is caught.
@retval EFI_SUCCESS The next sub file is obtained.
@retval EFI_INVALID_PARAMETER The ParentDir is not a directory.
@retval EFI_NOT_FOUND No more sub file exists.
@retval EFI_DEVICE_ERROR Something error while accessing media.
**/
EFI_STATUS
FatReadNextDirectoryEntry (
IN PEI_FAT_PRIVATE_DATA *PrivateData,
IN PEI_FAT_FILE *ParentDir,
OUT PEI_FAT_FILE *SubFile
)
{
EFI_STATUS Status;
FAT_DIRECTORY_ENTRY DirEntry;
CHAR16 *Pos;
CHAR16 BaseName[9];
CHAR16 Ext[4];
ZeroMem ((UINT8 *) SubFile, sizeof (PEI_FAT_FILE));
//
// Pick a valid directory entry
//
while (1) {
//
// Read one entry
//
Status = FatReadFile (PrivateData, ParentDir, 32, &DirEntry);
if (EFI_ERROR (Status)) {
return EFI_DEVICE_ERROR;
}
//
// We only search for *FILE* in root directory
// Long file name entry is *NOT* supported
//
if (((DirEntry.Attributes & FAT_ATTR_DIRECTORY) == FAT_ATTR_DIRECTORY) || (DirEntry.Attributes == FAT_ATTR_LFN)) {
continue;
}
//
// if this is a terminator dir entry, just return EFI_NOT_FOUND
//
if (DirEntry.FileName[0] == EMPTY_ENTRY_MARK) {
return EFI_NOT_FOUND;
}
//
// If this not an invalid entry neither an empty entry, this is what we want.
// otherwise we will start a new loop to continue to find something meaningful
//
if ((UINT8) DirEntry.FileName[0] != DELETE_ENTRY_MARK) {
break;
}
}
//
// fill in the output parameter
//
EngFatToStr (8, DirEntry.FileName, BaseName);
EngFatToStr (3, DirEntry.FileName + 8, Ext);
Pos = (UINT16 *) SubFile->FileName;
SetMem ((UINT8 *) Pos, FAT_MAX_FILE_NAME_LENGTH, 0);
CopyMem ((UINT8 *) Pos, (UINT8 *) BaseName, 2 * (StrLen (BaseName) + 1));
if (Ext[0] != 0) {
Pos += StrLen (BaseName);
*Pos = '.';
Pos++;
CopyMem ((UINT8 *) Pos, (UINT8 *) Ext, 2 * (StrLen (Ext) + 1));
}
SubFile->Attributes = DirEntry.Attributes;
SubFile->CurrentCluster = DirEntry.FileCluster;
if (ParentDir->Volume->FatType == Fat32) {
SubFile->CurrentCluster |= DirEntry.FileClusterHigh << 16;
}
SubFile->CurrentPos = 0;
SubFile->FileSize = DirEntry.FileSize;
SubFile->StartingCluster = SubFile->CurrentCluster;
SubFile->Volume = ParentDir->Volume;
//
// in Pei phase, time parameters do not need to be filled for minimum use.
//
return Status;
}
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