From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolas Dechesne Subject: Re: the Usage of ROM and RAM of Cortex-M3 on OMAP4 Date: Tue, 21 May 2013 15:52:27 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from mail-oa0-f44.google.com ([209.85.219.44]:53695 "EHLO mail-oa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752612Ab3EUNws (ORCPT ); Tue, 21 May 2013 09:52:48 -0400 Received: by mail-oa0-f44.google.com with SMTP id n12so817959oag.17 for ; Tue, 21 May 2013 06:52:47 -0700 (PDT) In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Barry Song <21cnbao@gmail.com> Cc: "pandaboard@googlegroups.com" , linux-omap@vger.kernel.org On Tue, May 21, 2013 at 12:04 PM, Barry Song <21cnbao@gmail.com> wrote: > Hi All, > typically on OMAP4, Cortex-A9 will load the Cortex-M3 firmware and let > M3 run from the firmware. for example, on Android, Linux kernel will > use remoteproc module to load ducati-m3-core0.xem3 of Ducati. > but after reading the datasheet of OMAP4, there are internal 16KB ROM > and 64KB RAM for Cortex-M3. And the ROM is bootable. I'd like to know > who is using the embedded ROM and RAM and how they use. and can the > Cortex-M3 boot from ROM directly by itself? > i don't think the ROM is being used. at least i am not aware of anyone who would have developed a ROM code for Ducati... so i don't think you can use the ROM. as for the RAM if you refer to what's called 'SL2 memory', it's being used by the codecs (IVAHD), it's just RAM that can be used freely if you don't use IVAHD.