amd64/111952: Boot panic due to missing BIOS smap on install cds (HP dc5750 SFF)

[IZ-FreeBSD0701-nospam at hs-karlsruhe.de]

The following reply was made to PR amd64/111952; it has been noted by GNATS.

From: IZ-FreeBSD0701-nospam at hs-karlsruhe.de
To: bug-followup at FreeBSD.org
Cc:  
Subject: Re: amd64/111952: Boot panic due to missing BIOS smap on install cds (HP dc5750 SFF)
Date: Mon, 21 May 2007 15:38:41 +0200

 This problem hit FreeBSD-i836 on the HP dc5750 as well.
 
 The 7.0-CURRENT snapshot from May 10th will only find 64 MB out of 1 GB
 installed. The loader print "BIOS 639/784064 kB" while the Kernel print
 "real memory = 67108864 (64 MB)". Asking the loader about the SMAP will
 print an empty line.
 
 This is the same with an older 6.2-STABLE. A more recent 6.2-STABLE of May
 18th prints the same in the loader, while the kernel print "real memory =
 1048576000 (1000 MB)", but the kernel fails to mount the root filesystem.
 Either automatically or manually provided.
 
 I think the cause for that is the on-board video-adapter which uses the
 system RAM. If I reduce the amount of usable memory by
 "hw.physmem=803561472" (a value detected by NetBSD on the same machine)
 in /boot/loader.conf the kernel will boot without a problem.
 
 Some remote kernel debugging sessions showed that in the function getmemsize()
 in /sys/i386/i386/machdep.c the kernel failed to get the memory map with
 INT 15:E820 and finally uses the RTC value for extended memory.
 
 The machine uses the newest system BIOS 786E3 v02.22.