Re: [U-Boot] usb flash boot on am335x machines
2015-01-26 17:46 GMT+02:00 Jon Cormier : > 26.1.8.6 Thanks Jon! My interpretation from codes was pretty much what you described that USB boot really was "modified network boot". I'm not too sure that this was HW restriction (=CPU) but merely u-boot boot strategy decision as am335x does have boot order strapping also for USB boot. It would be nice if I could find clear reason why USB flash boot won't work apart from the fact that u-boot code for am335x is not currently written in that way. If it turns out that usb flash boot could be made possible by u-boot patching, it would be also nice if anyone knew if this https://gitorious.org/rowboat/u-boot/commit/aaa9d5c083252218fd89afa68161f96bb7daa04c worked, so that I would not waste my time trying to modify them for u-boot 2013.10 if they did not work. Thanks, Matti ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
Re: [U-Boot] usb flash boot on am335x machines
> Date: Mon, 26 Jan 2015 08:35:51 +0200 > From: matti kaasinen > To: "u-boot@lists.denx.de" > Subject: [U-Boot] usb flash boot on am335x machines > Message-ID: > > Content-Type: text/plain; charset="utf-8" > > Hi! > > I have tried to find solution to get am335x based Silica/Pengwyn board > booting from usb flash. U-boot on that board is based on u-boot 2013.10. I > flashed it with similar configuration as mmc flash, but I did not find > combination of configuration variables to get proper spl code generated. I > studied codes and it seemed like am33x devices were left out from usb spl > generation parts. Is there some kind of fundamental reason to prevent > am335x devices not to boot from usb flash. If not, would anyone know the > configuration combination for this set-up. > If you read the TRM carefully (26.1.8.6 USB Boot Procedure), you'll find out that the 335x doesn't support usb flash drive boot at the hardware level. The USB boot option that is available creates a RNDIS ip connection with a computer and then it does a network boot. I'll agree that this wasn't what I was expecting when I saw USB boot. The only way to support a USB flash boot would be if the SPL was loaded some other means (NOR, NAND, MMC, etc) and it mounted the flash drive and booted from it. > > In fact, I found more than three years old patch that seems to make usb > boot set-up for am335x devices: > https://gitorious.org/rowboat/u-boot/commit/aaa9d5c083252218fd89afa68161f96bb7daa04c > However, it seems that these changed have somehow not been included in the > mainline codes. Is there specific reason for this? Sorry if this doesn't correctly link to original post. I'm unsure how I'm supposed to reply to an email in a mailing list digest. -- Jonathan Cormier CriticalLink ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
[U-Boot] usb flash boot on am335x machines
Hi! I have tried to find solution to get am335x based Silica/Pengwyn board booting from usb flash. U-boot on that board is based on u-boot 2013.10. I flashed it with similar configuration as mmc flash, but I did not find combination of configuration variables to get proper spl code generated. I studied codes and it seemed like am33x devices were left out from usb spl generation parts. Is there some kind of fundamental reason to prevent am335x devices not to boot from usb flash. If not, would anyone know the configuration combination for this set-up. In fact, I found more than three years old patch that seems to make usb boot set-up for am335x devices: https://gitorious.org/rowboat/u-boot/commit/aaa9d5c083252218fd89afa68161f96bb7daa04c However, it seems that these changed have somehow not been included in the mainline codes. Is there specific reason for this? Best regards, Matti Kaasinen ___ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
