that a buffer's b_blkno would be valid. This is true when vmiodirenable
is turned off because the B_MALLOC'd buffer's data is invalidated when
the buffer is destroyed. But when vmiodirenable is turned on a buffer
can be reconstituted from its VMIO backing store. The reconstituted buffer
will have no knowledge of the physical block translation and the result is
serious directory corruption of the CDROM.
The solution is to fix cd9660_blkatoff() to always BMAP the buffer if
b_lblkno == b_blkno.
MFC after: 0 days
etc. The only bit of debugging left is performing dual output to both
the screen and COM1. Also, the twiddle is still disabled since it seems
to do weird things to the serial dump. cdboot now has 880 bytes to spare.
to the El Torito standard for CD booting, a CD may boot in "No emulation"
mode without using a floppy image. In this mode, the BIOS loads a program
off of the CD into memory and creates a BIOS device using 2048 byte sectors
for the CD. According to the standard, this program can be up to 0xFFFF
virtual (512-byte) sectors long. The old cdldr depended on this by having
the BIOS load the entire loader and the small cdldr stub as one binary
similar to pxeboot so that cdldr didn't have to read the CD to find the
loader. However, the NT no emulation loader just uses 1 disk sector
(4 virtual sectors), so it seems that at least some BIOS writers just did
enough to get NT to boot by only loading 1 sector and ignoring the sector
count. Thus, while cdldr should have worked in theory, it doesn't in
practice. This replacment fits entirely in 1 sector and includes simple
ISO 9660 support. It looks for /boot/loader on the CD and loads it up
using the BIOS. This allows us to not have to depend on the limited size
of floppy images but use a full GENERIC kernel for CD-ROM installs in the
future, among other things.
This version of cdboot is a bit bloated as it includes some useful
debugging routines that people can pull to use in other x86 assembly
modules. Even with all the debugging cruft, we still have 272 bytes to
spare.
devices in 'lsdev' output rather than printing out a pointer to the
print function since the user really could care less about the pointer
value. Perhaps this was intended to be a debugging printf?
when debugging boot problems. It is not on by default but is enabled via
the BTX_SERIAL variable. The port and speed can be set via the same
variables used by boot2 and the loader.
Add an ``UPTIME'' variable to indicate the bundle uptime.
It's now possible to put something like this in ppp.linkdown
for a server setup:
MYADDR:
log Session closing: User USER, address HISADDR, up UPTIME
Fixed some memory leakage with commands that expand words.
Made some functions static.
Fixed a diagnostic bug (iface add .... SIOCDIFADDR)
be set to 1 to make FreeBSD and Tru64 coexist peacefully on a dual
boot system and not clobber each other's year in the TOY clock.
(Tru64 uses an offset 52 years higher than one would expect)
Obtained from: NetBSD
MFC After: 1 week
