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Grex > Micros > #199: FreeBSD, Linux, or other PC Unixes? |  |
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| 25 new of 257 responses total. |
dang
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response 56 of 257:
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Feb 12 03:24 UTC 1999 |
The superblock is just the first block of a partition. If there is
nothing in the MBR, such as if you've just gotten a new hard drive or
just installed windows, then the BIOS runs the program in the first
block (read superblock) the the partition marked active. It has the
same kind of space restrictions as the MBR, almost. If the BIOS is
running it, it needs to be withing BIOS addressable space, which is 1024
if you have a brain-dead BIOS. (If so, upgradeing your BIOS will almost
certainly cure it.)
Re: FreeBSD screw-up: I run FreeBSD as the only OS on my computer at
work, and I've installed any number of times, with no problem. From
what you've said, it sounds like no partition was marked as active,
and/or you didn't install the FreeBSD Bootloader. That's optional.
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mdw
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response 57 of 257:
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Feb 12 03:47 UTC 1999 |
The superblock is a block near the start of the filesystem that
describes the organization of that filesystem. It includes a magic
number (to say it's a so-so type of filesystem), and various parameters
that the filesystem uses to locate the other data structures on that
filesystem, such as the inode table, free block bitmaps, etc. The
superblock is usually *not* block 0, because block 0 is reserved for the
boot logic. In edition 7 Unix (ca. 1979 technology), the boot block was
512 bytes, and the superblock started in block 1 (blocks then being 512
bytes). In the berkeley filesystem (ca. 1984), multiple copies of the
superblock are written to disk, scattered onto different cylinders of
the disk. This makes it slightly easier to recover from certain kinds
of disk catastrophes (like something that trashes the "real" superblock
at the start of the disk.) 512 bytes is plenty of space for a really
dumb optimized boot strap module in pdp-11 assembler, that is just smart
enough to load "/boot" from the same disk and filesystem. In the
berkeley fast filesystem (variants of which are used in SunOS 4 and
386bsd), 8192 bytes of space at the start of the filesystem are reserved
for boot logic. 8192 bytes makes it easier to port this logic to new
systems, and makes it possible to write the logic in C on many systems.
This logic is "in addition" to the logic in the MBR on 386 systems;
generally, the MBR would invoke the boot block which would load /boot
which would load /vmunix (or /bsd or whatever the kernel is called on
your system). In SunOS, the boot block has the locations of /boot
written into it; a program named "installboot" must be run in order to
write the locations of /boot into the boot block logic.
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pfv
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response 58 of 257:
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Feb 12 05:40 UTC 1999 |
Somehow, I think we're talking the same thing w/ different
nomenclature..
yeah, the MBR is supposed to vector the bios to the /boot
partition and it's loading whatever the heck lilo creates from all
the assorted kernels you save as well as other OS's you care to
run.. I'd bet it's a chunk of lilo and either the actual kernel
or a chunk of what HAD been used to load DOS or Doze..
Near as I can tell now, the old slackware system that got
codwalloped was entirely due to my being a total neophyte to
building kernels and writing a zdisk/bootdiskette.. Because I
hadn't prepared said floppy, 95 got away with hammering me and I
had no idea how to get access to either /boot or / - thus ended
a brief flirtation with slackware..
Additionally, having been fried by 95 before, I am not at all
anxious to tempt the fates ever again.. There isn't anything for
Doze I can't live without or substitute something related.
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toking
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response 59 of 257:
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Feb 12 17:45 UTC 1999 |
resp:56 well, when I was trying to install freebsd as a second OS I kept
selecting to have the boot manager thing installed, but I'd assumed that
with it being the only system on the HD I could get away with the second
option (standard boot record)
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mwg
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response 60 of 257:
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Feb 13 20:13 UTC 1999 |
Re#57: If all else fails, you can boot with your original slackware setup
disks, mount your Linux partitions on the RamDisk file system, then re-run
lilo at the bash prompt, which should regenerate your LILO MBR. (Unless
something has trashed /etc/lilo.conf.) Then issue a shutdown command and
see what happens.
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mwg
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response 61 of 257:
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Feb 13 20:14 UTC 1999 |
Frack! I meant #58.
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dang
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response 62 of 257:
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Feb 13 22:30 UTC 1999 |
resp:59 No, that won't work. That only works if you have another
intelligent boot loader (such as NT or OS2) already running that you a)
don't want to trash and b) can configure to run FreeBSD. If FreeBSD is
alone, you have to install the bootloader from it, or nothing will boot.
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jshafer
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response 63 of 257:
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Feb 14 06:09 UTC 1999 |
Re: my floppy difficulties, back there somewhere, I got around
the problem by rebooting to Win95 (Actually whatever DOS comes
with Win95) and copying the files to the hard disk, then rebooting
in FreeBSD and mounting the DOS partition.
I just got a new external modem, and am now grexing from FreeBSD.
As soon as I figure out how to configure my X-windows display
stuff so I can get a display bigger than 320x200, and figure out
which of the ports I installed was the POP3 client, I may be ready
to do away w/ M$ in general...
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pfv
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response 64 of 257:
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Feb 14 16:45 UTC 1999 |
XF86Config is a LOT of fun.. Just remember to always leave the
^alt+[backspace] enabled ;-)
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jshafer
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response 65 of 257:
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Feb 14 19:33 UTC 1999 |
Thanks, Pete!
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dang
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response 66 of 257:
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Feb 17 05:16 UTC 1999 |
And keep a backup copy of one that works... :)
Actually, I've found that xf86config (the program, not the file) works
pretty well. If you want high color depth, tho, you're pretty much
stuck with a -bpp 32 somewhere on some command line.
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pfv
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response 67 of 257:
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Feb 17 06:22 UTC 1999 |
Gods yes...
Switching X versions needed a new config - it said.. Thankfully,
I'd saved the old one - in paranoid fashion.. the OLD one worked
all the time.. the new one was an abomination!
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gull
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response 68 of 257:
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Feb 17 22:11 UTC 1999 |
Re #66: Or do what I did. Edit startx (it's just a shell script) to make
-bpp 32 the default.
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toking
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response 69 of 257:
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Feb 18 16:55 UTC 1999 |
O.K. I finally got X working, but I'm stuck with some pretty crappy
color (just what does a color depth of 8 = in terms of number of
colors?) and suggestions on how to make that a little better? (I know
that in Windows I can set it to 16 bit
Ohh yeah....once you have FreeBSD installed is there some way to
reinstall the bootloader thing? (i'm stuck booting from floppy right
now...)
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pfv
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response 70 of 257:
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Feb 18 17:17 UTC 1999 |
Use "XF86config" - 8 bit is.. 256 colors (guys?)
Yeah, 16 or 24 bit make life tolerable..
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toking
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response 71 of 257:
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Feb 18 17:38 UTC 1999 |
I'm under the direct assumption that somewhere on my system there is a
program that I can run called XF86config, if so, where is it? do I run
it from inside X? ^---C?
ohh yeah...I've tried searching the web to no avail...anyone know where
I can find something about getting the MWave modem thats built into an
IBM ThinkPad 755CDV working under freebsd?
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dang
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response 72 of 257:
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Feb 19 00:19 UTC 1999 |
No, the program is xf86config, all lowercase. The config file itself is
capitalized like this: XF86Config. 8 bit color is indeed 256 colors.
You can actually use more than 256 colors, but only 256 at one time. If
you have 8 bit color, you usually get bizarre color changes when you
select programs like netscape, because they load thier own colormap. If
you are using startx to start X, then you can do this:
startx -- -bpp n
where n is one of 8, 16, 24, or 32. That coresponds to 256 colors, High
Color, and True Color (both the last two) on Windows. Its 256, 65,536,
16 million, and 4e9 colors. If you use xdm to start X, you will need
to edit it's config files and add a "-bpp n" to the line that has the X
server listed.
I know of no way to install the bootloader in FreeBSD other than by
installing. There probably is such a way, but I've never needed it.
Try http://www.freebsd.org which is a pretty good web site.
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eprom
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response 73 of 257:
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Feb 19 02:06 UTC 1999 |
hmm..the bootloader thingy? try /stand/sysinstall as root
then go to the post-config menu..then to fdisk then type "q" to quit
that should get you to the bootload thingy option...then go back to fdisk
and type "w" for write changes....theres probillly a more simple way
but i dunno know how....
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pfv
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response 74 of 257:
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Feb 19 17:28 UTC 1999 |
Hmm.. I find:
/usr/X11R6/bin/XF86Setup
No "xf[86config]" of any type.. We're heading into system
differences, I suspect. Sorry about misleading about, I'd have
SWORN I ran that..
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dang
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response 75 of 257:
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Feb 20 22:17 UTC 1999 |
I have /usr/X11R6/bin/xf86config, which is a standard part of XFree86.
If you installed X yourself, you didn't install the Xcfg.tgz package,
which is very suprising. It's listed as needed. If it came that way
from your distribution, that's again surprising. I'd switch
distributions. There is a program called Xconfigurator which runs a
stripped down X server and gives you a nice windows configuration
program. You might try that. I don't really like it, tho.
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pfv
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response 76 of 257:
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Feb 21 12:17 UTC 1999 |
Yeppers, I suspect the Xconfigurator is what I've been using
of late..Either I went too far in "cleaning house", or RedHat-
stuff took a few liberties..
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jshafer
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response 77 of 257:
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Feb 21 12:46 UTC 1999 |
Anyone here used Accelerated X? XFree86 doesn't support my i740
AGP video card, & i'm not sure if there's anything I can do to
make it work or not. I haven't done too much mucking around with
it, but what I have done leads me to think that paying $75 for a
product that _should_ work right out of the box might be worthwhile.
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toking
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response 78 of 257:
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Feb 22 16:40 UTC 1999 |
(found xf86config, didn' do me too much good, so I think I"ll just have
to live with 8bpp)
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dang
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response 79 of 257:
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Feb 24 19:31 UTC 1999 |
(resp:78 if you need more than 8 bpp, you need a command line option on
the command line that starts the actual X server. If you are using
startx, then try "startx -- -bpp 32" which will start with 32 bpp.
Don't forget the "--", which signals startx that the following options
are for X rather than xinit. If you use xdm, then you need to edit
/etc/X/xdm/Xservers and add " -bpp 32" to the end of the line containing
/usr/X11R6/bin/X.)
resp:77 I use Accelerate X for my Diamond Monster Fusion. It's a brand
new alpha server. However, until recently, I couldn't use Accelerated X
because there wasn't a server. There is a way around it. Look here:
http://www.uno.edu/~adamico/banshee/
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jshafer
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response 80 of 257:
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Feb 25 12:23 UTC 1999 |
Hmm. Not sure how useful that will be, as I'm not using a banshee or
Linux, but I'll check it out in more detail later... Thanks.
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