From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg0-f68.google.com ([74.125.83.68]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fXYvn-0003A5-Qq for linux-mtd@lists.infradead.org; Mon, 25 Jun 2018 21:21:53 +0000 Received: by mail-pg0-f68.google.com with SMTP id i7-v6so6624901pgp.2 for ; Mon, 25 Jun 2018 14:21:40 -0700 (PDT) Date: Mon, 25 Jun 2018 15:21:37 -0600 From: Rob Herring To: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Brian Norris , David Woodhouse , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Mark Rutland , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, Jonas Gorski , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= Subject: Re: [PATCH 1/2] dt-bindings: mtd: document Broadcom's TRX firmware format binding Message-ID: <20180625212137.GA16487@rob-hp-laptop> References: <20180612104434.15232-1-zajec5@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180612104434.15232-1-zajec5@gmail.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Jun 12, 2018 at 12:44:33PM +0200, Rafał Miłecki wrote: > From: Rafał Miłecki > > Broadcom based home router devices use TRX firmware format. It's a > container that can hold few partitions. If operating system is expected > to access them it has to understand that format and parse flash data > accordingly. > > Signed-off-by: Rafał Miłecki > --- > .../bindings/mtd/partitions/brcm,trx.txt | 35 ++++++++++++++++++++++ > 1 file changed, 35 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt > > diff --git a/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt > new file mode 100644 > index 000000000000..e590b884e5ac > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt > @@ -0,0 +1,35 @@ > +Broadcom TRX Container Partition > +================================ > + > +TRX is Broadcom's official firmware format for the BCM947xx boards. It's used by > +most of the vendors building devices based on Broadcom's BCM47xx SoCs and is > +supported by the CFE bootloader. > + > +Design of the TRX format is very minimalistic. Its header contains > +identification fields, CRC32 checksum and the locations of embedded partitions. > +Its purpose is to store a few partitions in a format that can be distributed as > +a standalone file and written in a flash memory. > + > +Container can hold up to 4 partitions. The first partition has to contain a > +device executable binary (e.g. a kernel) as it's what the CFE bootloader starts > +executing. Other partitions can be used for operating system purposes. This is > +useful for systems that keep kernel and rootfs separated. > + > +TRX doesn't enforce any strict partition boundaries or size limits. All > +partitions have to be less than the 4GiB max size limit. > + > +There are two existing/known TRX variants: > +1) v1 which contains 3 partitions > +2) v2 which contains 4 partitions > + > +Required properties: > +- compatible : (required) must be either: "brcm,trx-v1" or "brcm,trx-v2" > + followed by "brcm,trx" What is the purpose of brcm,trx? Either that alone is enough or you need v1/v2 to distinguish the difference. You shouldn't need both. Rob