diff --git a/ShellPkg/Application/Shell/FileHandleWrappers.c b/ShellPkg/Application/Shell/FileHandleWrappers.c index 655854b25d..bcce055321 100644 --- a/ShellPkg/Application/Shell/FileHandleWrappers.c +++ b/ShellPkg/Application/Shell/FileHandleWrappers.c @@ -1148,15 +1148,35 @@ FileInterfaceEnvDelete( EFI_STATUS EFIAPI FileInterfaceEnvRead( - IN EFI_FILE_PROTOCOL *This, - IN OUT UINTN *BufferSize, - OUT VOID *Buffer + IN EFI_FILE_PROTOCOL *This, + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ) { - return (SHELL_GET_ENVIRONMENT_VARIABLE( - ((EFI_FILE_PROTOCOL_ENVIRONMENT*)This)->Name, - BufferSize, - Buffer)); + EFI_STATUS Status; + + *BufferSize = *BufferSize / sizeof (CHAR16) * sizeof (CHAR16); + if (*BufferSize != 0) { + // + // Make sure the first unicode character is \xFEFF + // + *(CHAR16 *)Buffer = gUnicodeFileTag; + Buffer = (CHAR16 *)Buffer + 1; + *BufferSize -= sizeof (gUnicodeFileTag); + } + + Status = SHELL_GET_ENVIRONMENT_VARIABLE ( + ((EFI_FILE_PROTOCOL_ENVIRONMENT*)This)->Name, + BufferSize, + Buffer + ); + if (!EFI_ERROR (Status) || (Status == EFI_BUFFER_TOO_SMALL)) { + // + // BufferSize is valid and needs update when Status is Success or BufferTooSmall. + // + *BufferSize += sizeof (gUnicodeFileTag); + } + return Status; } /**