From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Thu, 21 Jan 2016 13:32:57 +0100 Subject: [Buildroot] [PATCH] board: add support for Freescale i.MX6UL Evaluation Kit In-Reply-To: <56A0C3B7.40900@free.fr> References: <1453300220-29113-1-git-send-email-julien.boibessot@free.fr> <20160120211015.79807c32@free-electrons.com> <56A0C3B7.40900@free.fr> Message-ID: <20160121133257.38d9a56a@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Julien, On Thu, 21 Jan 2016 12:40:39 +0100, Julien Boibessot wrote: > > I first started to use genimage, yes, but as I wanted to mimic Freescale > microSD partitionning I was stucked by the fact that genimage > (apparently) doesn't handle VFAT partitions. Indeed i.MX6UL microSD > Freescale's format is: > * 1MB free > * U-Boot > * VFAT partition starting at offset 8M to store kernel and dtbs (size 16MB) > * EXT2 rootfs on the remaining space. > > So I ended up in using i.XM28EVK way of doing > (board/freescale/imx28evk/create-boot-sd.sh). > Do you agree ? genimage is perfectly capable of creating a vfat partition, see board/raspberrypi/genimage-raspberrypi.cfg for an example. > > Why ? Any reason to use EABI over EABIhf, which is now the default in > > Buildroot for Cortex-A processors ? > > Well i.MX6UL has no VFPU, only a NEON, so I thought it was a good idea, > no ? :-) What is your source for this information, because it seems to be wrong. According to ARM (http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0463f/index.html): """ The Cortex-A7 MPCore processor implements the ARMv7-A architecture with the following architecture extensions: [...] - Vector Floating-Point version 4 (VFPv4) architecture extension for floating-point computation that is fully compliant with the IEEE 754 standard. """ So, the Cortex-A7 (which is the core used in the i.MX6UL) has a mandatory VFPv4 unit. Also, according to Freescale (http://cache.nxp.com/files/32bit/doc/fact_sheet/IMX6SRSFS.pdf), in the column for i.MX6UL: """ 128 KB L2 cache, NEON?, VFP, TrustZone? """ So, please use BR2_EABIHF, and improve your systems by using hard-float instead of soft-float :-) Best regards, Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com