/**
Worker function that extends the size of an open file.
The extension is filled with zeros.
@param[in] Fcb Internal description of the opened file
@param[in] Size The number of bytes, the file has to be extended.
@retval EFI_SUCCESS The file was extended.
@retval EFI_DEVICE_ERROR The last issued semi-hosting operation failed.
**/
STATIC
EFI_STATUS
ExtendFile (
IN SEMIHOST_FCB *Fcb,
IN UINTN Size
)
{
RETURN_STATUS Return;
UINTN Remaining;
CHAR8 WriteBuffer[128];
UINTN WriteNb;
UINTN WriteSize;
Return = SemihostFileSeek (Fcb->SemihostHandle, Fcb->Info.FileSize);
if (RETURN_ERROR (Return)) {
return EFI_DEVICE_ERROR;
}
Remaining = Size;
SetMem (WriteBuffer, 0, sizeof(WriteBuffer));
while (Remaining > 0) {
WriteNb = MIN (Remaining, sizeof(WriteBuffer));
WriteSize = WriteNb;
Return = SemihostFileWrite (Fcb->SemihostHandle, &WriteSize, WriteBuffer);
if (RETURN_ERROR (Return)) {
return EFI_DEVICE_ERROR;
}
Remaining -= WriteNb;
}
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;
}
EFI_STATUS
FileWrite (
IN EFI_FILE *File,
IN OUT UINTN *BufferSize,
IN VOID *Buffer
)
{
SEMIHOST_FCB *Fcb = NULL;
EFI_STATUS Status;
UINTN WriteSize = *BufferSize;
Fcb = SEMIHOST_FCB_FROM_THIS(File);
Status = SemihostFileWrite (Fcb->SemihostHandle, &WriteSize, Buffer);
if (!EFI_ERROR(Status)) {
// Semihost write return the number of bytes *NOT* written.
*BufferSize -= WriteSize;
Fcb->Position += *BufferSize;
}
return Status;
}
/**
Worker function that truncate a file specified by its name to a given size.
@param[in] FileName The Null-terminated string of the name of the file to be opened.
@param[in] Size The target size for the file.
@retval EFI_SUCCESS The file was truncated.
@retval EFI_DEVICE_ERROR The last issued semi-hosting operation failed.
**/
STATIC
EFI_STATUS
TruncateFile (
IN CHAR8 *FileName,
IN UINTN Size
)
{
EFI_STATUS Status;
RETURN_STATUS Return;
UINTN FileHandle;
UINT8 *Buffer;
UINTN Remaining;
UINTN Read;
UINTN ToRead;
Status = EFI_DEVICE_ERROR;
FileHandle = 0;
Buffer = NULL;
Return = SemihostFileOpen (
FileName,
SEMIHOST_FILE_MODE_READ | SEMIHOST_FILE_MODE_BINARY,
&FileHandle
);
if (RETURN_ERROR (Return)) {
goto Error;
}
Buffer = AllocatePool (Size);
if (Buffer == NULL) {
Status = EFI_OUT_OF_RESOURCES;
goto Error;
}
Read = 0;
Remaining = Size;
while (Remaining > 0) {
ToRead = Remaining;
Return = SemihostFileRead (FileHandle, &ToRead, Buffer + Read);
if (RETURN_ERROR (Return)) {
goto Error;
}
Remaining -= ToRead;
Read += ToRead;
}
Return = SemihostFileClose (FileHandle);
FileHandle = 0;
if (RETURN_ERROR (Return)) {
goto Error;
}
Return = SemihostFileOpen (
FileName,
SEMIHOST_FILE_MODE_WRITE | SEMIHOST_FILE_MODE_BINARY,
&FileHandle
);
if (RETURN_ERROR (Return)) {
goto Error;
}
if (Size > 0) {
Return = SemihostFileWrite (FileHandle, &Size, Buffer);
if (RETURN_ERROR (Return)) {
goto Error;
}
}
Status = EFI_SUCCESS;
Error:
if (FileHandle != 0) {
SemihostFileClose (FileHandle);
}
if (Buffer != NULL) {
FreePool (Buffer);
}
return (Status);
}