From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fortini Matteo Date: Mon, 12 Oct 2009 15:54:59 +0200 Subject: [U-Boot] Linux seamless booting In-Reply-To: <7c4144600910120623k2c9aea89ia0f255164f03ff89@mail.gmail.com> References: <4AD30DF0.1000901@mta.it> <7c4144600910120623k2c9aea89ia0f255164f03ff89@mail.gmail.com> Message-ID: <4AD33533.5030900@mta.it> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Yes, that's what we're currently using, but the problem is a little broader: I should answer to CAN messages in at most 100-200ms from powerup, and that can be done in u-boot. However, handing CAN transmission control over to Linux is quite complicated nowadays, since it would involve passing structures in memory and hacking through device init. It'd be nice to have a framework with which u-boot could hand-over devices to Linux in a clean and defined way. We were thinking about starting some kind of development in that direction, but with very little resources, so I was looking for someone who had looked at the same problem. Thanks, Matteo Roberto Guerra ha scritto: > Did you try "setenv bootdelay 0" in uboot? > > On Mon, Oct 12, 2009 at 7:07 AM, Fortini Matteo wrote: > >> Hi all, >> we've been working on a PPC512x board booting with u-boot + linux 2.6.24.6, >> and one major issue for our application is boot time. >> >> Right now, we went down to less than 6s boot time (i.e. time from power off >> to launch of the user app), even with some drivers installed, i.e.: >> >> * CAN bus >> * GPU on PCI bus >> * USB host >> * UBI >> >> with r/o squashfs root and r/w ubifs configuration filesystem mounted from a >> NOR flash memory. >> >> This time could be enough for the high-level application (we're showing a >> splash screen in about 2-3s so it's ok if the main app takes a little longer >> to come up), but the whole system is connected to others via CAN and we >> can't afford the "black out" period between u-boot and linux. >> >> Some other operating systems (e.g. QNX) have this "seamless booting" >> function, in which drivers are started in stages, so that a (minimal) >> functionality can be given in milliseconds, and more functionalities come up >> as time goes by. >> >> Is there a way to support something similar with the u-boot -> linux >> solution? >> >> Thank you, >> Matteo >> _______________________________________________ >> Linuxppc-dev mailing list >> Linuxppc-dev at lists.ozlabs.org >> https://lists.ozlabs.org/listinfo/linuxppc-dev >> >> > . > >