From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikita Kiryanov Date: Thu, 14 Jul 2016 18:46:50 +0300 Subject: [U-Boot] [PATCH v2 0/4] ARM: imx: enhance support for the cm-fx6 module In-Reply-To: References: Message-ID: <20160714154650.GA13093@arkadi-linux.compulab.local> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Christopher, Stefano, Whole series: Acked-by: Nikita Kiryanov On Tue, Jul 12, 2016 at 11:37:33PM +0200, christopher.spinrath at rwth-aachen.de wrote: > Hi, > > this is v2 of the series. To address the review comments of v1, v2 has an > addtional patch (2/4) touching include/fdt_support.h (thus, I added Simon > to the recipients). > > The original cover letter was (for a discussion cf. [2]): > > this series aims at enhancing support for the cm-fx6 module. In > particular, with respect to the upstream linux kernel. > > The first patch improves the default environment. It is non-functional > but makes it more convenient to adapt certain settings. > > The later two patches add mtd partition support for the on-board spi > flash chip. They pick up the discussion about specifying a default > partitioning in the device tree from here [1]. In short: adding the > default partitioning to the device tree was rejected by the linux/ > device tree community during mainlining large parts of the device tree. > It was proposed to implement the partition/mtd handling in u-boot. > On the other hand, it was argued that the flash chip becomes some > kind of "black-box" since there will be no partition labeling (in > particular, with old u-boot versions). > > IMHO defining the mtd partitioning has the following (dis-)advantages: > > Advantages: > - It is easier for the user to change the partitioning (e.g. to use > the unsued 1MB free space). > > - The flash ship is used entirely for u-boot. So it is quite natural > that u-boot manages it. Also, moving the partition table to it > allows us to change the layout in future versions of u-boot (almost > independently of the kernel - there are still non-device tree kernels). > > - U-Boot becomes the single point of definition for all device tree > kernels. Otherwise, each kernel (vendor vs. upstream + version) > would ship its own partitioning. Moreover, u-boot has to know > something about the partitioning, too, because it has to know where > the environment is saved. > > Disadvantages: > - Users of the upstream linux kernel have to use a recent u-boot > version to avoid the "black box" effect. A concrete impact is > that the update routine (described/proposed by CompuLab) does > not work out of the box with older u-boot versions. > > - Updating u-boot is something users might not want or miss to do. > > However, I think nowadays it is ok to demand a recent u-boot in > combination with the upstream kernel. The cm-fx6 wouldn't be > the first board doing so. Hence, I propose these patches here. > > Cheers, > Christopher > > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-June/434562.html > [2] http://lists.denx.de/pipermail/u-boot/2016-June/258546.html >