- 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>
