At Thu, 09 Jul 2020 18:16:26 -0700, "Greg A. Woods" <woods%planix.ca@localhost> wrote:
Subject: USB console support "was: NetBSD-7.0 boots OK and NetBSD-8.0 hangs/crashes during boot on a MacBook7,1)
>
> 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
For what it's worth my Dell servers and my MacBook Pro have such USB
debug ports.
The MacBook Pro even has two of them, and I'm pretty sure one of them is
connected to the external ports.
On the Dell though this seems to be the port that connects to the DRAC.
From "lspci -vvv":
00:1d.7 USB controller: Intel Corporation 631xESB/632xESB/3100 Chipset EHCI USB2 Controller (rev 09) (prog-if 20 [EHCI])
Subsystem: Dell Device 01b2
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin A routed to IRQ 11
Region 0: Memory at de500000 (32-bit, non-prefetchable)
Capabilities: [50] Power Management version 2
Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [58] Debug port: BAR=1 offset=00a0
From "usbdevs -dv":
addr 1: high speed, self powered, config 1, EHCI root hub(0x0000), NetBSD(0x0000), rev 1.00(0x0100)
uhub2
port 1 addr 2: high speed, self powered, config 1, product a001(0xa001), Dell(0x413c), rev 0.00(0x0000)
uhub5
port 1 addr 3: full speed, self powered, config 1, DRAC5(0x0000), Dell(0x413c), rev 0.00(0x0000), serial 0000000
uhidev0
uhidev1
port 2 powered
port 2 powered
port 3 powered
port 4 powered
port 5 addr 4: high speed, self powered, config 1, USB2 Hub(0x6560), Cypress Semiconductor(0x04b4), rev 0.0b(0x000b)
uhub6
port 1 powered
port 2 powered
port 3 powered
port 4 powered
port 6 powered
port 7 powered
port 8 powered
--
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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