At Mon, 06 Jul 2020 13:13:03 -0700, "Greg A. Woods" <woods%planix.ca@localhost> wrote: Subject: Re: NetBSD-7.0 boots OK and NetBSD-8.0 hangs/crashes during boot on a MacBook7,1 > > Or indeed any device with any kind of USB port, e.g. a laptop. Oh, and I wanted to mention something else that I'd forgotten about but stumbled across again the other day while debugging servers: Xen supports writing console messages to a special kind of USB port: "console=dbgp" indicates that Xen should use a USB debug port. http://xenbits.xenproject.org/docs/4.11-testing/misc/xen-command-line.html There's more about it in this thread: https://lists.xenproject.org/archives/html/xen-devel/2009-03/msg00436.html https://lists.xenproject.org/archives/html/xen-devel/2009-03/msg00458.html Further of interest is that Xen also supports writing to both a COM port and the "vga" console simultaneously. Indeed it may support writing to "dbgp" at the same time as well. This is something I looked into for NetBSD/i386 some time ago, but never got it fully working. To me I think it would be super incredibly valuable for the boot code to be able to talk to both a serial port and the "pc" console simultaneously. It is less important for the kernel to do so, but it still would be nice. -- Greg A. Woods <gwoods%acm.org@localhost> Kelowna, BC +1 250 762-7675 RoboHack <woods%robohack.ca@localhost> Planix, Inc. <woods%planix.com@localhost> Avoncote Farms <woods%avoncote.ca@localhost>
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