[flashrom] Using libflashrom from fwupd

[Richard Hughes]

On 17 August 2017 at 23:19, Nico Huber <nico.h at gmx.de> wrote:
>> typedef void(flashrom_progress_event_cb)(enum flashrom_progress_event event, char *reason, void *user_data);
> `char *reason`? see above.

I use libraries with const char* enums; and although it makes it easy
to add states the calling program never knows what to expect -- "add"
or "ADD", "add foo" or "add: foo" -- I'd really much prefer this to be
tightly controlled with an enum.

> In a simplified version (let's assume resets don't count), we could
> simply approximate everything with the size of the flash chip (or size
> of included regions if a layout is used). So total amount of progress
> for a read/write/verify would be three times the size. Read and verify
> would be linear, write rather bumpy, but does it matter?

I think it's fine.

> Richard, would it be feasible for your GUI visualization if you'd do the
> steps separately? e.g. you could make a backup, then you could pass the
> backup back to libflashrom together with the new data to be written
> (which would allow us to skip the usual read before write) and then
> finally call a function to verify everything.

So, that's ok, on the assumption we know what to do -- perhaps not all
chips need erasing...

> So basically you'd have
> three calls into libflashrom which take some time and would show three
> times a progress bar. If you wanted to show a total progress you'd have
> to do that manually then.

libflashrom would be called by fwupd, which would then proxy on a
percentage to the GUI, so I think it's fine that fwupd can control
what's happening. That's pretty much what it does for the other
userspace flash plugins.

Richard