to 4 bytes free. I removed a printf (the Keyboard yes/no) since it is of
marginal value and sed'ed the generated asm output to remove the unwanted
aligns. There's probably a better way to gain a few extra bytes than
losing the printf. Shortening strings is probably a better option but this
should get us over the hurdle.
- Axe -fdata-sections as turning it on or off makes no difference. If
it did make a difference it would serve to bloat boot2 even further with
extra padding.
- Axe -fforce-addr. This gets us 32 bytes so we are down to only being
64-bytes over.
We still can't compile this with gcc 3.1. The problem seems to be that
the -fno-align-foo options don't actually work. Comparing the new and
old output it turns out that gcc is 4-byte padding all the functions and
labels and what not despite the passed in arguments thus adding the
unfortunate bloat to boot2.
modules split across several physical medias. Following is how it works:
The splitfs code, when asked to open "foo" looks for a file "foo.split"
which is a text file containing a list of filenames and media names, e.g.
foo.aa "Kernel floppy 1"
foo.ab "Kernel floppy 2"
foo.ac "Kernel and modules floppy"
For each file segment, the process is:
- try to open the file
- prompt "Insert the disk labelled <whatever> and press any key..."
- try to open the file
- return error if file could not be located
RE team is free to use this feature in the upcoming 5.0-DP1.
Reviewed by: msmith, dcs
because the buffers we use could end up spanning a 64k boundary.
Unfortunately it causes too much bloat (228 -> 72 bytes free) to
just reinstate the old malloc() function.
Instead, define a structure that contains all 4 buffers which must
not cross 64k boundaries. We allocate a 64k-aligned instance in
main() using the magic that was in the old boot2 malloc() function.
This brings the free space down to 168 bytes, but that is still
better than it was before revision 1.35 (136 bytes).
Reported by: Mike Brancato <funnyguy@digitalsmackdown.net>
Pointy-hat to: iedowse
done with boot1 on the alpha. We use 4k buffers regardless of the
actual filesystem block size.
Remove the simple malloc() implementation, as it is no longer used.
backing out the 1024 sector boot0, but revision 1.12 had nothing to do with
that. Instead, it documented various compile time options for boot0 and
allowed them to be overridden via make.conf or options on the make
command line.
- Change the 'fopen' keyword to accept a mode parameter. Note that this
will break existing 4th scripts that use fopen. Thus, the loader
version has been bumped and loader.4th has been changed to check for a
sufficient version on i386 and alpha. Be sure that you either do a full
world build or install or full build and install of sys/boot after this
since loader.old won't work with the new 4th files and vice versa.
PR: kern/32389
Submitted by: Jonathan Mini <mini@haikugeek.com>
Sponsored by: ClickArray, Inc.
This flag adds a pausing utility. When ran with -p, during the kernel
probing phase, the kernel will pause after each line of output.
This pausing can be ended with the '.' key, and is automatically
suspended when entering ddb.
This flag comes in handy at systems without a serial port that either hang
during booting or reser.
Reviewed by: (partly by jlemon)
MFC after: 1 week
no emulation mode. Unlike other BIOS devices, this device uses 2048 byte
sectors. Also, the bioscd driver does not have to worry about slices
or partitions.
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.
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.
dedicated" mode. This was specifying that there are 256 (illegal!)
heads on the disk. If bioses store that in a byte, and it gets truncated
to 0, then that almost certainly causes the infamous divide-by-zero
nightmare.
This is also most likely the reason why the Thinkpad T20/A20 series
were locking up when FreeBSD was installed. This is also the most likely
reason why a boot1 being present causes an IA64 box to lock up at boot.
(removing the "part4" stuff from boot1.s fixes the IA64 boxes and would
most likely have fixed the T20/A20 and some TP600E series thinkpads)
- When the video BIOS is called to clear the region (x, y)-(79, 24)
(by scrolling), the slashed region in Fig.1 is cleared. CD() is
supposed to clear the region shown in Fig.2.
x x
+-------+ +-------+
| | | |
y| ////| y| ////|
| ////| |///////|
| ////| |///////|
+-------+ +-------+
Fig.1 Fig.2
- Don't move the cursor during this operation.
- Be consistent about placing spaces around keywords and
operators; don't mix statements like "if(A==B)" and "if (X == Y)",
"return(0)" and "return (-1)", "P=10" and "Q = 0", etc.
- Consitently indent lines. It's not good to indent by 8 columns
in one part of the file, and by 4 columns in the other part.
is turned off by default and could be enabled by defining LOADER_BZIP2_SUPPORT
make variable. Also make gzip support optional (turned on by default) -
it could be turned off via LOADER_NO_GZIP_SUPPORT make variable.
Please note, that due to limit on the amount of memory available to the
loader(8), it is possible to load modules/kernels compressed with the smallest
block size supported by the bzip2 - 100k (`-1' bzip2(1) option), however
even in this mode bzip2(1) usually provides better compression ratio than
gzip(1) in its best compression mode.
MFC after: 1 month
the ACPI module if the system apperars to be ACPI compliant.
This is an initial cut; the load should really be done by Forth support
code, and we should check both the BIOS build date and a blacklist.
actual end of the section. The new gas (binutils) puts in additional padding
which was misaligning the concatenated btx loader.
Reported by: Oliver Hartmann <ohartman@klima.physik.uni-mainz.de>,
Harti Brandt <brandt@fokus.gmd.de>
Tested by: Oliver Hartmann <ohartman@klima.physik.uni-mainz.de>,
David Wolfskill <dhw@whistle.com>, ps
Reviewed by: jhb
MFC after: 1 day
the first sector of the emulated floppy to contain a valid MS-DOS BPB that
it can modify. Since boot1 is the first sector of boot.flp, this resulted
in the BIOS overwriting part of boot1: specifically the function used to
read in sectors from the disk.
Submitted by: Mark Peek <mark@whistle.com>
Submitted by: Doug Ambrisko <ambrisko@ambrisko.com>
PR: i386/26382
Obtained from: NetBSD, OpenBSD (the example BPB)
MFC after: 1 month
longer includes machine/elf.h.
* consumers of elf.h now use the minimalist elf header possible.
This change is motivated by Binutils 2.11.0 and too much clashing over
our base elf headers and the Binutils elf headers.
fatal trap. Also, reload the GDT register to point to BTX's GDT before
playing around with the segment registers to return to real mode. This is
helpful if the kernel causes a fatal exception before it has setup its own
IDT and fault handlers. For example, if one happens to break mtx_init().
Without these changes BTX would recursively page fault (if paging was not
disabled) or triple fault and reset the CPU (without the GDT reload)
instead of providing a potentially useful register dump.
Reviewed by: rnordier
Taking over the sector following the MBR causes problems on some
machines, and the actual gains are fairly small in terms of how
the space is presently used.
Since we need a number of further features (eg. handling extended
partitions) that can't be readily accommodated in the basic boot0
design anyway, rather choose to implement the additional stuff
separately and concentrate on compatibility rather than features
here.
to allow commonality between varying platforms. This is a step
towards parsing the diskless configuration information with MI code
inside the kernel.
Export the interface hardware address to the kernel, so that it is possible
to determine the boot interface with certainty.
Export the NFS filehandle for the root mount to the kernel, so that the
kernel does not need to perform a mount RPC call.
BOOT_BTX_NOHANG, then BTX will be compiled with the appropriate flags so
that it reboots after a fault instead of hanging forever.
Requested by: ps
Approved by: rnordier
identifier to the DHCP server. Now you can check for this string
in your dhcp configuration to decide whether you will hand out a
lease to the client or not.
to 0x600 via a 'rep movsw'. Once that was done, %cx was zero, so we could
simply use 'movb' to update the lower byte of %cx in preparation for
zeroing out the fake partition entry used to boot to other drives via F5.
Well, in the new boot0, we don't actually relocate ourselves, instead it
is easier to create the fake partition entry first and then just use it to
get the BIOS to load all of boot0 into memory at 0x600. However, since we
aren't doing the relocate code anymore, we don't know that %cx == 0 when
we hit the 'movb' to setup %cx for clearning the fake partition entry.
Thus, if %ch != 0 when the BIOS started boot0, then it would end up zeroing
a lot more memory than just 8 words. The solution is to do a word move of
$8 into %cx.
Debugging help from: David Wolfskill <dhw@whistle.com>
Linux kernel image, and is designed to be dropped into a Linux system
and booted via LILO. Once booted, the user is greeted by the FreeBSD
loader. This still isn't quite complete, as the the root= specification
from LILO isn't currently passed to the loader yet.
- Autodetection and support of the BIOS EDD extensions to work around the
1024 cylinder limit on all but really ancient BIOS's.
- To work around some BIOS's which break when EDD is used with older drives,
we only attempt to use EDD if the cylinder is > 1023.
- Since this new code required more space than we had left, expand boot0 to
2 sectors (1024 bytes) in length.
- Add support for boot0 being multiple sectors using predefined constants.
If boot0 needs to be extended in the future, all that is required is
bumping the NUM_SECTORS constant.
- Now that we have more room to work with, add a few more fs type
descriptions while making others more verbose.
