ironsheep/p2-flash-fs

Chip's Flash FS with a standard API for accessing the FLASH chip on the P2 Edge Module.

p2-flash-fs's Issues

Off by one error on value returned from read() ?

and have you...

• I updated to the latest version available
• My code conforms to calling sequences shown in demo code

Version of P2 Flash FS

Tested in latest github sources

Is this a regression?

No or unsure. This never worked, or I haven't tried before.

P2 Hardware, Compiler used

P2 Board: P2 Eval Board
P2 Compiler: both flexspin and PNut v39

Description of problem

Read seems to return 1 byte more than the requested number of bytes. For example:

CON
  _clkfreq = 250_000_000

OBJ
  flash: "flash_fs"

DAT
buf	BYTE 128

PUB demo() | r, handle
  flash.mount()
  handle := flash.open(@"rwblocks.bin", "r")
  if handle >= 0
    r := flash.read(handle, @buf[0], 32)
    debug("requested 32 bytes, read returned ", sdec_(r))
    flash.close(handle)
  flash.unmount()

outputs:

Cog0  requested 32 bytes, read returned 33

Additional information

No response

Write should return number of bytes written

Issue being Addressed

The write function returns only a status, and no indication of how many bytes were written.

Enhancement

The write function should probably act like Unix (and Windows) and return the count of bytes actually written, rather than a status of 0 on success. This will allow us to detect things like flash full, and also be more consistent with how other OSes work.

Alternatives

I can work around this in the flexspin VFS layer, but it seems like it might surprise other users as well who are used to POSIX and Windows APIs.

Additional information

No response