From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Fri, 7 Jul 2017 10:30:28 -0400 Subject: [U-Boot] [PATCH] spl: dm: Make it possible for the SPL to pick its own DTB from a FIT In-Reply-To: <1499427879-9045-1-git-send-email-jjhiblot@ti.com> References: <1499427879-9045-1-git-send-email-jjhiblot@ti.com> Message-ID: <20170707143028.GF22707@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Fri, Jul 07, 2017 at 01:44:39PM +0200, Jean-Jacques Hiblot wrote: > u-boot can be embedded within a FIT image with multiple DTBs. It then > selects at run-time which one is best suited for the platform. > Use the same principle here for the SPL: put the DTBs in a FIT image, > compress it (LZO, GZIP, or no compression) and append it at the end of the > SPL. > > Signed-off-by: Jean-Jacques Hiblot > --- > > The impact in terms of boot time is not high when using LZO but I gues it can vary > from platform to platform. > The size of the SPL binary is increased (1.5kB more code on ARM), but the compression > really flattens the DTBS. so at the end of the day, enabling this option doesn't add much. > > Here are some sumbers with a DRA7 platform (numbers in bytes): > size delta with ref > MLO.reference 123450 > MLO.lzo_1_DTB 123715 +265 > MLO.lzo_4_DTB 124237 +787 > MLO.gzip_4_DTB 132006 +8556 > MLO.no_comp_4_DTB 134184 +10734 Bearing in mind that you said in a follow up this is RFC, I'm ignoring all of the stuff that I believe you would fix in a v1. At the heart of it, are you able to tell different boards before you have a DTB loaded? I keep coming back to the problem that for SPL it seems like we should be able to do what Franklin did for keystone (https://patchwork.ozlabs.org/patch/777242/) and have a 'fake' dts file that represents the SoC such that any real boards can get U-Boot loaded and from there have the real board dtb be used. Or am I forgetting something? Thanks! -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: