Re: [flashrom] [PATCH] dummyflasher.c: add an "empty" parameter and initialize with random bytes by default

[Carl-Daniel Hailfinger]

Am 22.07.2011 12:54 schrieb Uwe Hermann:
> On Thu, Jul 21, 2011 at 11:55:32PM +0200, Stefan Tauner wrote:
> > On Thu, 21 Jul 2011 23:27:34 +0200
> > Carl-Daniel Hailfinger  wrote:
> > > Am 21.07.2011 17:54 schrieb Stefan Tauner:
> > > > previously the dummies were initialized to be empty (all ones), which makes writes skip
> > > > erasing altogether. with this patch the default is to fill it with random bytes instead and the
> > > > old behavior can be enforced with stating "empty=yes" on the command line.
> > > >
> > > > Signed-off-by: Stefan Tauner
> > >
> > > Does the following not work for you?
> > >
> > > dd if=/dev/urandom bs=1k count=4k of=oldimage.bin
> > > flashrom -p dummy:emulate=SST25VF032B,image=oldimage.bin -w newimage.bin
>
> Works fine here, but having a commandline option such as the
> "content=..." in the updated patch is worthwhile IMHO, it saves the user
> quite some unneeded hassle to create dummy images on a filesystem,

Which user? Nobody except the active flashrom developers will ever test
dummyflasher on DOS, and I hope our skills are not so limited that
copying oldimage.bin to the same directory as flashrom.exe is impossible
for us.
> which is possibly even a bit harder on DOS or elsewhere due to missing
> dd and so on.

Then generate it on Linux where you cross-compile the DOS binary.
> Also in the qflashrom GUI I'd personally like to be able
> to present the user with a drop-down of possible dummy chip contents
> (which are autogenerated by libflashrom).

You could use the pattern generator which is already present in
flashrom, and write the generated pattern to a file which is supplied
for flashing. That way, you can use those patterns for real programmers
as well. The current content=/empty= proposal has zero benefits outside
dummyflasher, and for that you can use dd or the pattern generator anyway.
> The "image=" option should stay of course, it's very useful too, e.g.
> for specially crafted test images etc. But for a few simple cases such
> as 0x00, 0xff, random, etc. the "content=" option makes sense, IMHO.
> > did i mention that the man page needs an update? :P
>
> That too, yes.

I should have sent a man page patch for that last night. No idea why it
didn't show up. Let me check and resend.

Regards,
Carl-Daniel