From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Sat, 30 May 2015 16:38:20 -0400 Subject: [U-Boot] Booting Wandboard through USB In-Reply-To: <556A190C.2010704@boundarydevices.com> References: <55683580.8060803@bergerie> <20150530164921.GB1728@bill-the-cat> <5569F236.4080905@bergerie> <556A190C.2010704@boundarydevices.com> Message-ID: <20150530203820.GD1728@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 Sat, May 30, 2015 at 01:09:48PM -0700, Eric Nelson wrote: > On 05/30/2015 10:24 AM, Vincent Stehl? wrote: > > On 05/30/2015 06:49 PM, Tom Rini wrote: > > .. > >> The second would be trying to "fake" things such that for > >> imx_usb_loader you can pass both SPL and u-boot.img, and SPL is > >> run, inits memory and just exists and then u-boot.img is loaded > >> and run, similar to how with the non-SPL case you can use the > >> loader to pass in u-boot.imx as well as a kernel, ramdisk, etc, > >> into DDR. > > > > I wonder if we could use the i.MX6 ROM "plugin"[1] mechanism with u-boot > > SPL, to download it through USB, have it configure the DDR and return to > > the ROM, in a way that would allow us to resume downloading the second > > stage u-boot through USB... > > > > Best regards, > > > > V. > > > > [1] Chapter "8.8 Plugin Image" of the i.MX6D/Q Reference Manual. > > ;) This is an even older idea: > http://lists.denx.de/pipermail/u-boot/2012-September/thread.html#134444 > > In my earlier e-mail, I said that this was more complicated because > it involves hacking the image creation process (and perhaps some > linker scripts). > > It also requires that SPL images have some form of flag telling them > not to boot, but return to the ROM boot loader after initializing DDR > (i.e. they need to optionally act like a plugin). Well there is precendce these days for doing special things to cooperate with ROM, we do something not totally dissimilar for sunxi I believe, in some cases. -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: