From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: To: David Gibson Subject: Re: dtc: Don't force alignment of cell list data In-Reply-To: Your message of "Fri, 02 Nov 2007 16:54:26 +1100." <20071102055426.GN19839@localhost.localdomain> References: <20071102055426.GN19839@localhost.localdomain> Date: Mon, 05 Nov 2007 08:59:44 -0600 From: Jon Loeliger Message-Id: Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , So, like, the other day David Gibson mumbled: > At present, defining a property as, say: > foo = [abcd], ; > > Will cause dtc to insert 2 bytes of zeros between the abcd and the > ffffffff, to align the cell form data. > > Doing so seemed like a good idea at the time, but I don't believe > there are any users who actually rely on this behaviour. Segher > claims that OF has some defined bindings which include properties an > unaligned subsection of which is interpreted as 32-bit ints (i.e. like > cell data). > > Worse, this alignment will cause nothing but pain when we add > expression support to dtc (when celldata is included in a larger > bytestring expession, we won't know the size of the preceding chunk of > the expression until it's evaluated, so we would have to carry > alignment fixup information right through the expression evaluation > process). > > Therefore, this patch kills off this alignment behaviour. > > Signed-off-by: David Gibson Applied. jdl