Date: Tue, 4 Feb 2003 00:21:36 +0000 (GMT) From: Andrew Gordon <arg-bsd@arg1.demon.co.uk> To: Lucky Green <shamrock@cypherpunks.to> Cc: <freebsd-current@FreeBSD.ORG> Subject: RE: L440gx+ serial BIOS needs text mode Message-ID: <20030204000002.P42367-100000@server.arg.sj.co.uk> In-Reply-To: <002f01c2cbc0$22a2d010$6601a8c0@VAIO650>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 3 Feb 2003, Lucky Green wrote: > > However, the Intel L440gx+ motherboard I have (it came in a VA Linux > rackmount) seems to have a separate CPU performing all kinds of > monitoring tasks, watchdog, etc, so I was hoping this separate CPU was > actually performing the serial console task. As I read it on page 64 of > the manual (download from Intel), the second serial port is actually > connected through a multiplexer to the Baseboard Management Controller > (Dallas 82CH10) in my configuration. > ftp://download.intel.com/support/motherboards/server/l440gx/254151-003.p > df I've used several generations of these intel boards, though not the exact one which you have, most recently the se7500wv2. All of them are more conventional than it might appear: - The 'screen scraper' for serial access to the BIOS works from software on the main (i386) CPU. The earlier machines didn't have on-board video, so mapped in some ordinary RAM to the video area if you ran them without a video card fitted; later machines have video hardware and the console redirection polls this RAM. Either way, it's BIOS software generating ANSI escapes out of the ordinary serial port, and this stops when the OS boots. - The management CPU sits between the external serial port connector and the UART in the main CPU's chipset. Hence the OS running on the main CPU always thinks it's got a standard COM port, it's just a question of whether data sent to/from that port makes it to the external connector or gets subverted by the management CPU. - On the latest machines featuring 'serial over LAN', you can persuade the management CPU to subvert the serial port and pass the data over one of the ethernet ports. This seems to use a proprietary protocol, but if you have one Windows machine somewhere with the Intel management software loaded on it, you can use that to proxy the protocol for any number of managed machines - ie. telnet to port 623 on the Windows machine, then connect back to the target machine and get attached to the serial console (and so get a FreeBSD login, if that's what is running on COM2). - Medium-aged machines seem to have all the hardware to subvert the serial and ethernet ports, but won't do serial redirection apart from controlling the BIOS. Upgrading the BMC software didn't help on the machine I had in this category. Disclaimer: the above is just from playing with the machines and reading the documentaton, so I may be wrong. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030204000002.P42367-100000>