[PATCH 1/1] MTD: Unlocking all Intel flash that is locked on power up

[Nicolas Pitre]

On Fri, 9 Nov 2007, Justin Treon wrote:

> > > > > Adding the ability to unlocking all Intel flash that is locked on power up. 
> > > > > Currently only Intel P30 flash is unlocked.  All Intel flash is locked on
> > power
> > > > up.
> > > > 
> > > > What if you wanted for some of your flash partitions to remain locked?
> > > > 
> > > 
> > > It will not unlock any partitions that are listed are read only in your map.  
> > > 
> > > I prefer to use the command line partitioning so if I have
> > > "mtdparts=M18:0x80000(blob)ro,0x280000(kernel)," mtd0, the boot loader, will
> > remain
> > > locked and mtd1, the kernel, will be unlocked.  
> > 
> > That might be your preference.  But locked flash blocks are more likely 
> > to be immune against software bugs for example.  Unconditionally 
> > unlocking all blocks without regards for the wish of the user is a bad 
> > idea.  This is policy that is better decided elsewhere.
> 
> Setting an MTD partition to read only can be done in the maps files as 
> will as in the command line.  Those wishing to protect a partition 
> should always set it to read only for the very same reasons you 
> mentioned.

I know.  I happen to be the original flash partition code author.
But for really sensitive data I'd prefer for that partition to remain 
locked at the hardware level too.

> > I think that adding a mount flag to jffs2 to unlock the concerned 
> > partition when it is about to be mounted read-write would be a much 
> > better solution.  This has been discussed on the list long ago IIRC, but 
> > no one came forward with a patch.
> > 
> 
> Adding the ability to unlock a partition on mount is not a bad idea, but it should
> not be the only way.  I often write to an mtd block device without mounting it and I
> do not always use jffs2 as my writable filing system.

Never heard of the MTD flash-unlock user space utility?


Nicolas