From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Masaki Sawanobori" To: Subject: [ECOS] I/O driver lookup handler: read/write mode Date: Tue, 30 Nov 1999 02:59:00 -0000 Message-id: <062c01bf3b22$2a8be000$437201aa@atlantis7> X-SW-Source: 1999-11/msg00078.html Hello, I am implementing a simple flash memory file system in the framework of eCos I/O device driver model and C language libc stdio module so the user can access a file using fopen() as follows. FILE *fp = fopen("/dev/flash0/filename", "r"); FILE *fp = fopen("/flash0/filename", "w"); The problem is that the second paramter(read/write mode) of fopen() is not passed down to a "lookup" device driver handler(via the cyg_io_lookup function). The "lookup" handler has no way of returning a correct return/error value without knowing whether a file(existing or non-existing) is for read or write. I would not like to resort to a workaround of adding a read/write mode specifier as part of a filename parameter like "/nvram/filename/w" or "/nvram/filename/r" or "/nvramR"/filename" or "/nvramW/filename". This would be redundant for fopen(). Is there any other workaround or a solution for this situation? Am I missing something ? Here is another wish about I/O device driver handlers. There is no "close" handler. I could use a "close" handler since it seems to be a right place to free memory allocated in my "lookup" handler. -- Masaki S.