EFI_STATUS
FileSetPosition (
IN EFI_FILE *File,
IN UINT64 Position
)
{
SEMIHOST_FCB *Fcb = NULL;
UINTN Length;
EFI_STATUS Status;
Fcb = SEMIHOST_FCB_FROM_THIS(File);
if (!Fcb->IsRoot) {
Status = SemihostFileLength (Fcb->SemihostHandle, &Length);
if (!EFI_ERROR(Status) && (Length < Position)) {
Position = Length;
}
Status = SemihostFileSeek (Fcb->SemihostHandle, (UINT32)Position);
if (!EFI_ERROR(Status)) {
Fcb->Position = Position;
}
} else {
Fcb->Position = Position;
Status = EFI_SUCCESS;
}
return Status;
}
STATIC
EFI_STATUS
GetFileInfo (
IN SEMIHOST_FCB *Fcb,
IN OUT UINTN *BufferSize,
OUT VOID *Buffer
)
{
EFI_FILE_INFO *Info = NULL;
UINTN NameSize = 0;
UINTN ResultSize;
UINTN Index;
UINTN Length;
EFI_STATUS Status;
if (Fcb->IsRoot == TRUE) {
ResultSize = SIZE_OF_EFI_FILE_INFO + sizeof(CHAR16);
} else {
NameSize = AsciiStrLen (Fcb->FileName) + 1;
ResultSize = SIZE_OF_EFI_FILE_INFO + NameSize * sizeof (CHAR16);
}
if (*BufferSize < ResultSize) {
*BufferSize = ResultSize;
return EFI_BUFFER_TOO_SMALL;
}
Info = Buffer;
// Zero out the structure
ZeroMem (Info, SIZE_OF_EFI_FILE_INFO);
// Fill in the structure
Info->Size = ResultSize;
if (Fcb->IsRoot == TRUE) {
Info->Attribute = EFI_FILE_READ_ONLY | EFI_FILE_DIRECTORY;
Info->FileName[0] = L'\0';
} else {
Status = SemihostFileLength (Fcb->SemihostHandle, &Length);
if (EFI_ERROR(Status)) {
return Status;
}
Info->FileSize = Length;
Info->PhysicalSize = Length;
for (Index = 0; Index < NameSize; Index++) {
Info->FileName[Index] = Fcb->FileName[Index];
}
}
*BufferSize = ResultSize;
return EFI_SUCCESS;
}
/**
Write data to an open file.
@param[in] This A pointer to the EFI_FILE_PROTOCOL instance that
is the file handle to write data to.
@param[in out] BufferSize On input, the size of the Buffer. On output, the
size of the data actually written. In both cases,
the size is measured in bytes.
@param[in] Buffer The buffer of data to write.
@retval EFI_SUCCESS The data was written.
@retval EFI_ACCESS_DENIED Attempt to write into a read only file or
in a file opened in read only mode.
@retval EFI_DEVICE_ERROR The last issued semi-hosting operation failed.
@retval EFI_INVALID_PARAMETER At least one of the three input pointers is NULL.
**/
EFI_STATUS
FileWrite (
IN EFI_FILE *This,
IN OUT UINTN *BufferSize,
IN VOID *Buffer
)
{
SEMIHOST_FCB *Fcb;
EFI_STATUS Status;
UINTN WriteSize;
RETURN_STATUS Return;
UINTN Length;
if ((This == NULL) || (BufferSize == NULL) || (Buffer == NULL)) {
return EFI_INVALID_PARAMETER;
}
Fcb = SEMIHOST_FCB_FROM_THIS (This);
// We cannot write a read-only file
if ((Fcb->Info.Attribute & EFI_FILE_READ_ONLY)
|| !(Fcb->OpenMode & EFI_FILE_MODE_WRITE)) {
return EFI_ACCESS_DENIED;
}
//
// If the position has been set past the end of the file, first grow the
// file from its current size "Fcb->Info.FileSize" to "Fcb->Position"
// size, filling the gap with zeros.
//
if (Fcb->Position > Fcb->Info.FileSize) {
Status = ExtendFile (Fcb, Fcb->Position - Fcb->Info.FileSize);
if (EFI_ERROR (Status)) {
return Status;
}
Fcb->Info.FileSize = Fcb->Position;
}
WriteSize = *BufferSize;
Return = SemihostFileWrite (Fcb->SemihostHandle, &WriteSize, Buffer);
if (RETURN_ERROR (Return)) {
return EFI_DEVICE_ERROR;
}
Fcb->Position += *BufferSize;
if (Fcb->Position > Fcb->Info.FileSize) {
Fcb->Info.FileSize = Fcb->Position;
}
Return = SemihostFileLength (Fcb->SemihostHandle, &Length);
if (RETURN_ERROR (Return)) {
return EFI_DEVICE_ERROR;
}
Fcb->Info.PhysicalSize = Length;
return EFI_SUCCESS;
}
/**
Set information about a file.
@param[in] Fcb A pointer to the description of the open file.
@param[in] Info A pointer to the file information to write.
@retval EFI_SUCCESS The information was set.
@retval EFI_ACCESS_DENIED An attempt is made to change the name of a file
to a file that is already present.
@retval EFI_ACCESS_DENIED An attempt is being made to change the
EFI_FILE_DIRECTORY Attribute.
@retval EFI_ACCESS_DENIED The file is a read-only file or has been
opened in read-only mode and an attempt is
being made to modify a field other than
Attribute.
@retval EFI_WRITE_PROTECTED An attempt is being made to modify a
read-only attribute.
@retval EFI_DEVICE_ERROR The last issued semi-hosting operation failed.
@retval EFI_OUT_OF_RESOURCES A allocation needed to process the request failed.
**/
STATIC
EFI_STATUS
SetFileInfo (
IN SEMIHOST_FCB *Fcb,
IN EFI_FILE_INFO *Info
)
{
EFI_STATUS Status;
RETURN_STATUS Return;
BOOLEAN FileSizeIsDifferent;
BOOLEAN FileNameIsDifferent;
BOOLEAN ReadOnlyIsDifferent;
CHAR8 *AsciiFileName;
UINTN FileSize;
UINTN Length;
UINTN SemihostHandle;
//
// A directory can not be changed to a file and a file can
// not be changed to a directory.
//
if (((Info->Attribute & EFI_FILE_DIRECTORY) != 0) != Fcb->IsRoot) {
return EFI_ACCESS_DENIED;
}
AsciiFileName = AllocatePool (StrLen (Info->FileName) + 1);
if (AsciiFileName == NULL) {
return EFI_OUT_OF_RESOURCES;
}
UnicodeStrToAsciiStr (Info->FileName, AsciiFileName);
FileSizeIsDifferent = (Info->FileSize != Fcb->Info.FileSize);
FileNameIsDifferent = (AsciiStrCmp (AsciiFileName, Fcb->FileName) != 0);
ReadOnlyIsDifferent = CompareMem (
&Info->CreateTime,
&Fcb->Info.CreateTime,
3 * sizeof (EFI_TIME)
) != 0;
//
// For a read-only file or a file opened in read-only mode, only
// the Attribute field can be modified. As the root directory is
// read-only (i.e. VolumeOpen()), this protects the root directory
// description.
//
if ((Fcb->OpenMode == EFI_FILE_MODE_READ) ||
(Fcb->Info.Attribute & EFI_FILE_READ_ONLY) ) {
if (FileSizeIsDifferent || FileNameIsDifferent || ReadOnlyIsDifferent) {
Status = EFI_ACCESS_DENIED;
goto Error;
}
}
if (ReadOnlyIsDifferent) {
Status = EFI_WRITE_PROTECTED;
goto Error;
}
Status = EFI_DEVICE_ERROR;
if (FileSizeIsDifferent) {
FileSize = Info->FileSize;
if (Fcb->Info.FileSize < FileSize) {
Status = ExtendFile (Fcb, FileSize - Fcb->Info.FileSize);
if (EFI_ERROR (Status)) {
goto Error;
}
//
// The read/write position from the host file system point of view
// is at the end of the file. If the position from this module
// point of view is smaller than the new file size, then
// ask the host file system to move to that position.
//
if (Fcb->Position < FileSize) {
FileSetPosition (&Fcb->File, Fcb->Position);
}
}
Fcb->Info.FileSize = FileSize;
Return = SemihostFileLength (Fcb->SemihostHandle, &Length);
if (RETURN_ERROR (Return)) {
goto Error;
}
Fcb->Info.PhysicalSize = Length;
}
//
// Note down in RAM the Attribute field but we can not ask
// for its modification to the host file system as the
// semi-host interface does not provide this feature.
//
Fcb->Info.Attribute = Info->Attribute;
if (FileNameIsDifferent) {
Return = SemihostFileOpen (
AsciiFileName,
SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY,
&SemihostHandle
);
if (!RETURN_ERROR (Return)) {
SemihostFileClose (SemihostHandle);
Status = EFI_ACCESS_DENIED;
goto Error;
}
Return = SemihostFileRename (Fcb->FileName, AsciiFileName);
if (RETURN_ERROR (Return)) {
goto Error;
}
FreePool (Fcb->FileName);
Fcb->FileName = AsciiFileName;
AsciiFileName = NULL;
}
Status = EFI_SUCCESS;
Error:
if (AsciiFileName != NULL) {
FreePool (AsciiFileName);
}
return Status;
}
/**
Open a file on the host system by means of the semihosting interface.
@param[in] This A pointer to the EFI_FILE_PROTOCOL instance that is
the file handle to source location.
@param[out] NewHandle A pointer to the location to return the opened
handle for the new file.
@param[in] FileName The Null-terminated string of the name of the file
to be opened.
@param[in] OpenMode The mode to open the file : Read or Read/Write or
Read/Write/Create
@param[in] Attributes Only valid for EFI_FILE_MODE_CREATE, in which case these
are the attribute bits for the newly created file. The
mnemonics of the attribute bits are : EFI_FILE_READ_ONLY,
EFI_FILE_HIDDEN, EFI_FILE_SYSTEM, EFI_FILE_RESERVED,
EFI_FILE_DIRECTORY and EFI_FILE_ARCHIVE.
@retval EFI_SUCCESS The file was open.
@retval EFI_NOT_FOUND The specified file could not be found.
@retval EFI_DEVICE_ERROR The last issued semi-hosting operation failed.
@retval EFI_WRITE_PROTECTED Attempt to create a directory. This is not possible
with the semi-hosting interface.
@retval EFI_OUT_OF_RESOURCES Not enough resources were available to open the file.
@retval EFI_INVALID_PARAMETER At least one of the parameters is invalid.
**/
EFI_STATUS
FileOpen (
IN EFI_FILE *This,
OUT EFI_FILE **NewHandle,
IN CHAR16 *FileName,
IN UINT64 OpenMode,
IN UINT64 Attributes
)
{
SEMIHOST_FCB *FileFcb;
RETURN_STATUS Return;
EFI_STATUS Status;
UINTN SemihostHandle;
CHAR8 *AsciiFileName;
UINT32 SemihostMode;
UINTN Length;
if ((FileName == NULL) || (NewHandle == NULL)) {
return EFI_INVALID_PARAMETER;
}
if ( (OpenMode != EFI_FILE_MODE_READ) &&
(OpenMode != (EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE)) &&
(OpenMode != (EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_CREATE)) ) {
return EFI_INVALID_PARAMETER;
}
if ((OpenMode & EFI_FILE_MODE_CREATE) &&
(Attributes & EFI_FILE_DIRECTORY) ) {
return EFI_WRITE_PROTECTED;
}
AsciiFileName = AllocatePool (StrLen (FileName) + 1);
if (AsciiFileName == NULL) {
return EFI_OUT_OF_RESOURCES;
}
UnicodeStrToAsciiStr (FileName, AsciiFileName);
// Opening '/', '\', '.', or the NULL pathname is trying to open the root directory
if ((AsciiStrCmp (AsciiFileName, "\\") == 0) ||
(AsciiStrCmp (AsciiFileName, "/") == 0) ||
(AsciiStrCmp (AsciiFileName, "") == 0) ||
(AsciiStrCmp (AsciiFileName, ".") == 0) ) {
FreePool (AsciiFileName);
return (VolumeOpen (&gSemihostFs, NewHandle));
}
//
// No control is done here concerning the file path. It is passed
// as it is to the host operating system through the semi-hosting
// interface. We first try to open the file in the read or update
// mode even if the file creation has been asked for. That way, if
// the file already exists, it is not truncated to zero length. In
// write mode (bit SEMIHOST_FILE_MODE_WRITE up), if the file already
// exists, it is reset to an empty file.
//
if (OpenMode == EFI_FILE_MODE_READ) {
SemihostMode = SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY;
} else {
SemihostMode = SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY | SEMIHOST_FILE_MODE_UPDATE;
}
Return = SemihostFileOpen (AsciiFileName, SemihostMode, &SemihostHandle);
if (RETURN_ERROR (Return)) {
if (OpenMode & EFI_FILE_MODE_CREATE) {
//
// In the create if does not exist case, if the opening in update
// mode failed, create it and open it in update mode. The update
// mode allows for both read and write from and to the file.
//
Return = SemihostFileOpen (
AsciiFileName,
SEMIHOST_FILE_MODE_WRITE | SEMIHOST_FILE_MODE_BINARY | SEMIHOST_FILE_MODE_UPDATE,
&SemihostHandle
);
if (RETURN_ERROR (Return)) {
Status = EFI_DEVICE_ERROR;
goto Error;
}
} else {
Status = EFI_NOT_FOUND;
goto Error;
}
}
// Allocate a control block and fill it
FileFcb = AllocateFCB ();
if (FileFcb == NULL) {
Status = EFI_OUT_OF_RESOURCES;
goto Error;
}
FileFcb->FileName = AsciiFileName;
FileFcb->SemihostHandle = SemihostHandle;
FileFcb->Position = 0;
FileFcb->IsRoot = 0;
FileFcb->OpenMode = OpenMode;
Return = SemihostFileLength (SemihostHandle, &Length);
if (RETURN_ERROR (Return)) {
Status = EFI_DEVICE_ERROR;
FreeFCB (FileFcb);
goto Error;
}
FileFcb->Info.FileSize = Length;
FileFcb->Info.PhysicalSize = Length;
FileFcb->Info.Attribute = (OpenMode & EFI_FILE_MODE_CREATE) ? Attributes : 0;
InsertTailList (&gFileList, &FileFcb->Link);
*NewHandle = &FileFcb->File;
return EFI_SUCCESS;
Error:
FreePool (AsciiFileName);
return Status;
}
