cvs commit: src/sys/boot/i386/mbr Makefile mbr.s src/sys/boot/i386/boot2 Makefile boot1.S

[Yar Tikhiy]

On Sat, Dec 04, 2004 at 01:29:37PM -0800, Peter Wemm wrote:
> On Thursday 02 December 2004 11:01 am, Yar Tikhiy wrote:
> > yar         2004-12-02 19:01:46 UTC
> >
> >   FreeBSD src repository
> >
> >   Modified files:        (Branch: RELENG_5)
> >     sys/boot/i386/mbr    Makefile mbr.s
> >     sys/boot/i386/boot2  Makefile boot1.S
> >   Log:
> >   MFC:    Try using packet mode by default, but provide a user
> >           with a knob to disable it at build time--flag 0x80 for
> >           BOOT_MBR_FLAGS and BOOT_BOOT1_FLAGS.  In fact, disabling
> >           packet mode completely, even a test for it, should be
> >           necessary only for old and brain-damaged machines FreeBSD 5
> >           will hardly run on.
> 
> BTW: I tried to install 5.3-R on an empty 160G disk.  I created a single 
> 16G swap and the rest was a single fs (it was a test box).  boot2 could 
> not find the loader.
> 
> Is this the same problem that you've fixed, or is this something else?  

At least, it is likely to be that kind of a problem, as long as the
boot2 code uses a disk read subroutine from boot1.  Could you show
the BIOS disk geometry on that machine?

> Maybe having the rootfs start 16GB into the disk is a bad idea?

With a modern BIOS and bug-free loader, it shouldn't be a bad
idea.  The EDD interface to the disk BIOS (also known as packet
mode) uses 64-bit block addressing, thus allowing for fabulous disk
sizes, so the closest limit is that of the PC partition table, 2TB.

-- 
Yar