From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Message-ID: <17977.29234.367271.820951@cargo.ozlabs.ibm.com> Date: Thu, 3 May 2007 15:25:06 +1000 From: Paul Mackerras To: "Mark A. Greer" Subject: Re: [PATCH 3/13] powerpc: Add bootwrapper support for Marvell/mv64x60 hostbridge In-Reply-To: <20070427220245.GC14490@mag.az.mvista.com> References: <20070425234630.GA4046@mag.az.mvista.com> <20070425235619.GE4046@mag.az.mvista.com> <17969.37331.228482.225919@cargo.ozlabs.ibm.com> <20070427220245.GC14490@mag.az.mvista.com> Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Mark A. Greer writes: > Well, the firmware just doesn't do all the init that's required. And, > some of the init that it does do is wrong. For example, the window for > the MPSC (serial ctlr) to access main memory isn't set up so the kernel > mpsc driver can't dma. There are several other examles. > > All of this init should be in the firmware but its Motorola/ECC's > firmware and I/we have no control over it. Given that, I/we have to do > the init somewhere. Either in the kernel or the bootwrapper. > I vote for the bootwrapper but then your vote is the only one that actually > counts. :) How much of the setup is actually necessary for the bootwrapper to run, and how much could be deferred to setup_arch() time in the kernel? If nothing else, doing it in the kernel means that the code and data for it exist in compressed form in the zImage rather than uncompressed form. :) Also, how many lines of code (including definitions) would we avoid having in the kernel by having this stuff in the bootwrapper? Another question - is this setup something that will need to be done differently for different boards using the mv64x60, or is the same setup needed for all applications of the mv64x60? Paul.