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.
use the BIOS Equipment List to determine how many hard drives are
installed and if the drive number we received in %dl is valid.
- Don't bother to disable interrupts when setting up the stack. The 8086
and beyond implicitly disable interrupts after an instruction that sets
%ss (for example, a pop or a mov) so that you can safely set %ss and %sp
in two consecutive instructions. An exception to this is the lss
instruction, which can set both registers simultaneously and thus doesn't
need this hack.
- Add support for EDD BIOS extensions to support booting off of hard drives
of nearly arbitrary length.
- Add in support for the EDD (Enhanced Disk Drive) BIOS extensions to
use LBA mode for accessing drives past cylinder 1024. This should allow
us to load a kernel from anywhere on a newer drive up to 2 TB. Part
of this came from the PR below.
PR: i386/13847
Submitted by: Tor Egge <Tor.Egge@fast.no>
theory, this should allow the K7V Athlon motherboard to boot ok with boot
virus protection enabled. However, I have no hardware to test this. It
shouldn't break anything though. :)
Prodded by: Kelly Yancey <kbyanc@posi.net>
with the new binutils. Now that we have a decent assembler, all the old
m4 macros are no longer needed. Instead, straight assembly can be used
since as(1) now understands 16-bit addressing, branches, etc. Also,
several bugs have been fixed in as(1), allowing boot0.s to be further
cleaned up.
code instead of using 32-bit code and having to just "know" that it's
really 16-bit instructions when things run. This also allows the code
to use fewer macros and more actual assembly statements, which eases
maintenance. Unfortunately, due to as(1) brokenness, we still use m4
macros for all 16-bit addresses, and all short jumps (i.e., 8-bit
relative addresses in the jump instruction) must be wrapped in .code32
directives to avoid useless bloat by as(1). This also fixes a few
problems that were preventing boot0 from compiling with the latest
and greatest version of as(1).
below). This did not work previously because interrupts were
disabled when PXE calls were being made, and they must be enabled.
This should also allow us to be compliant with all newer PXE rom's
from Intel.
For PXE 0.99, this has been tested using the Intel N440BX motherboard
and I am confident it will work on the Intel L440GX motherboard.
Lots of help/information from: jhb, peter
I would like to thank Michael Johnston <michael.johnston@intel.com>,
Mike Henry <mike.henry@intel.com>, and all the other PXE developers
at Intel for their help, and information in helping solve this
problem.
from user mode. Don't disable interrupts when returning from vm86 mode
to user mode either. Now, we only disable interrupts before calling a
hardware interrupt handler, which is the only time we _should_ be
disabling interrupts.
Because of this, err, feature, any routine that one called in vm86 mode
had to re-enable interrupts by setting the interrupt flag or interrupts
would remain disabled even after the routine returned. For example, I
have a simple debugging routine that uses a vm86 mode function to dump
any arbitrary memory word that I use to read the BIOS timer or any other
memory location. This function does 1 load instruction from memory and
then returns. Since it didn't re-enable interrupts, the first time I
called it to read the BIOS timer, it disabled interrupts. This also
affected the PXE bootstrap as it needs interrupts enabled while it is
processing. This patch fixes both of those situations so that those
functions do not worry about having to enable interrupts. Hardware
interrupt handlers worked fine with the old code because they always
enable interrupts as part of their routine.
If you have any problems with the loader after this commit, please
let me know. I'd like to MFC it in a week or two since PXE support
needs it.
Noticed by: ps, Michael Johnston <michael.johnston@intel.com>
You may specify TFTP or NFS via compile time options in the loader,
but not both at this time.
Also, remove a warning about not knowing how to boot from network
devices. We can obviously do that now.
- Don't hard code 0x10000 as the entry point for the loader. Instead add
src/sys/boot/i386/Makefile.inc which defines a make variable with the
entry point for the loader. Move the loader's entry point up to
0x20000, which makes PXE happy.
- Don't try to use cpp to parse btxldr for the optional BTXLDR_VERBOSE,
instead use m4 to achieve this. Also, add a BTXLDR_VERBOSE knob in the
btxldr Makefile to turn this option on.
- Redo parts of cdldr's Makefile so that it now builds and installs cdboot
instead of having i386/loader/Makefile do that. Also, add in some more
variables to make the pxeldr Makefile almost identical and thus to ease
maintainability.
- Teach cdldr about the a.out format. Cdldr now parsers the a.out header
of the loader binary and relocates it based on that. The entry point of
the loader no longer has to be hardcoded into cdldr. Also, the boot
info table from mkisofs is no longer required to get a useful cdboot.
- Update the lsdev function for BIOS disks to parse other file systems
(such as DOS FAT) that we currently support. This is still buggy as
it assumes that a floppy with a DOS boot sector actually has a MBR and
parses it as such. I'll be fixing this in the future.
- The biggie: Add in support for booting off of PXE-enabled network
adapters. Currently, we use the TFTP API provided by the PXE BIOS.
Eventually we will switch to using the low-level NIC driver thus
allowing both TFTP and NFS to be used, but for now it's just TFTP.
Submitted by: ps, alfred
Testing by: Benno Rice <benno@netizen.com.au>
necessary. Pass an absolute block number too, instead of receiving a
relative one in realstrategy(), as bcache_strategy() requires this.
The fix is sligthly different from the one in the PR.
PR: 17098
Submitted by: John Hood <jhood@sitaranetworks.com>
1) Fix a bug in the int15 function 87 emulation where we only copied half
of what the BIOS asked for. This caused the Mylex RAID adapter to go
haywire and start trashing memory when you tried to boot from it.
2) Don't use interrupt 19 to reboot. Instead, set the reboot flag to a warm
boot and jump to the BIOS's reboot handler. int 19 doesn't clear memory
or restore the interrupt vector table, and thus really isn't safe. For
example, when booting off of PXE, the PXE BIOS eats up a chunk of memory
for its internal data and structures. Since we rebooted via int 19,
using the 'reboot' command in the loader resulted in that memory not
being reclaimed by the BIOS. Thus, after a few PXE boots, the system
was out of lower memory.
3) Catch any int 19 calls made by a BTX client or a user pressing
Ctrl-Alt-Delete and shutdown BTX and reboot the machine cleanly. This
fixes Ctrl-Alt-Delete in the loader and in boot2 instead of presenting
the user with a BTX fault.
Approved by: jkh
Found by: 1) by msmith
- Fix btxldr to preserve a NULL bootinfo pointer when it copies the kernel
arguments.
- Add the cdldr bootstrap program. This program is tacked onto the
beginning of the standard 3rd stage boot loader (/boot/loader) to form
the CD boot loader (/boot/cdboot). When a CD is booted, the cdboot file
is copied into memory instead and executed. The cdldr stub emulates the
environment normally provided by boot2 and then starts the loader. This
booting method does not emulate a floppy drive, but boots directly off of
the CD. This should fix the problems some BIOS's have with emulating a
2.88 MB floppy image.
- Add support to the loader to recognize that it has been booted by cdldr
instead of boot2 and use a simpler method of extracting the BIOS boot
device.
of %cr0 wasn't reloaded into %eax before being modified to turn protected
mode off if PAGING was not defined. The result was that the processor did
not exit protected mode, so when it tried to jump to segment 0x0 in the
next instruction to clear the prefetch cache like one should when leaving
protected mode, it actually tried to jump to a null selector, causing a
GPF.
for our use. Use the same search order for BIOS memory size functions
as the kernel will later use.
Allow the loader to use all of the detected physical memory (this will
greatly help people trying to load enormous memory disk images).
More correctly handle running out of memory when loading an object.
Use the end of base memory for the top of the heap, rather than
blindly hoping that there is 384k left.
Add copyrights to a couple of files I forgot.
-fschedule-insns as it wasn't such a big win with 2.95 after all.
Add the *BIG* win "-mpreferred-stack-boundary=2" optimiztion submitted by
Dima. GCC 2.95 ensures the stack frame is always properly [opitimally]
aligned by surrounding every function call by code simular to
"addl $-12, %esp" / "addl $12, %esp". Here we need the reduction in space,
with speed not an issue.
Remove some printf() calls, reduce size of buffers, and abbreviate
some strings.
Hopefully the boot people will fix this spamage after the cut over to
Gcc 2.95.2 as the system compiler.
either one gives us an additional 32 bytes of additional space available
when using EGCS 1.1.2. With GCC 2.95.2 -fforce-addr gives us 12 more bytes,
and adding -fschedule-insns gives us an additional 4 bytes.
Memory" called as function 0x87 of interrupt 0x15. Since the Mylex RAID
adapter's BIOS used this function to access memory (actually PCI bus
space) beyond 16 MB, this patch also allows BTX to address all 4 Gig of
possible address space on i386+. Since the loader does not have room for
4 MB of page tables, this was done by turning off paging.
Paging was turned off via a compile time setting which defaults to off.
To enable paging, simply define the make variable PAGING.
rnordier might want to clean this up later.
Submitted by: W. Gerald Hicks <wghicks@bellsouth.net>,
Bosko Milekic <bmilekic@ares.dsuper.net>
Reviewed by: msmith
Required by: Mylex RAID adapter's BIOS
numbers that we have been doing in the past, and read /etc/fstab off the
proposed root filesystem to determine the actual device name and vfs
type for the root filesystem. These are then exported to the kernel
via the environment variable vfs.root.mountfrom.
This should resolve the problem raised in PR 12315, and incidentally
makes it easier to determine what geometry the BIOS is actually using
(by way of boot -v and dmesg).
flag to the kernel to mount a CDROM as the root filesystem. Alternatively,
the boot_cdrom env var can be set.
As Mike Smith noted, "-C is the "wrong" way to do this", but this is
an acceptable stopgap in lieu of a better way.
PR: bin/11884
Reviewed by: msmith@freebsd.org
Use colons instead of semi-colons in the default init_path to behave like
UNIX instead of DOS.
Suggested by: bde
Reminded by: des (with no hint as to *which* man page).
Implement a new variable 'root_disk_unit' which supersedes
'num_ide_disks' and makes it possible to explicitly set the
root device unit number regardless of type considerations.
bootinfo.c
If we can't calculate a dev_t for the root disk, complain and
don't proceed to boot with an invalid boot device.
needs. This removes the dependancy on Perl for the generation of the
loader, allowing the world to be built on a perl-free system.
Submitted by: Joe Abley <jabley@clear.co.nz>
Note no matching commit for the Alpha, as the alpha boot0 stage does
not have the ability to prompt for user input.
PR: kern/9406
Submitted by: "Daniel C. Sobral" <dcs@newsguy.com>
Move the relocated boot1 and arg transfer space from 0x600/0x800 to
0x700/0x900. In theory this should make no difference, apart from the fact
that Buslogic controllers happen to use a few bytes at 0x600 for some sort
of scratch space for it's int 0x13 hook (!!!), causing the machine to crash
badly when the boot2 code makes it's callbacks into boot1 for disk IO.
Submitted by: Robert Nordier <rnordier@freebsd.org>
capabilities are: AF, AB, cm, ho, me, cd. The code is hidden behind
-DTERM_EMU - should it cause any problems, you can remove this define
to get back the old behaviour.
You'll find some examples how to use it in src/share/examples/bootforth.
Reviewed by: jkh
interface. Do some general consistency fixes and space optimizations.
Use of some freed-up space to defend against possible BIOS misfeatures.
boot2: Revise disk read interface to provide for boot1 changes. Free
up space for this.
and will bypass transfers for more than 8k. Blocks are invalidated after
2 seconds, so removable media should not confuse the cache.
The 8k threshold is a compromise; all UFS transfers performed by
libstand are 8k or less, so large file reads thrash the cache.
However many filesystem metadata operations are also performed using
8k blocks, so using a lower threshold gives poor performance.
Those of you with an eye for cache algorithms are welcome to tell me
how badly this one sucks; you can start with the 'bcachestats' command
which will print the contents of the cache and access statistics.
filesystems.
- New 'help' command and data in the help.* files (not yet installed),
provides topic and subtopic help, indexes, etc.
- Don't crash if the user tries to set an invalid console. Be helpful
instead.
- Expand tabs (badly) on the i386 video console.
- Some minor cosmetic changes.
- Use the ISA PnP enumerator.
- Use the new linker set code, throw out the gensetdefs stuff.
- Produce an intermediate loader image that has symbols stripped, to aid
- in debugging.
- Supply ISA port access functions required for ISA PnP
the boot.config settings are persistent, this seems to provide a
useful override capability, and should break only on broken
boot.config's.
Output a cosmetic newline if booting with no input.
Read boot.help before parsing boot.config. We were parsing
boot.config first, which could result in boot.help being read
from a different location (or not found), which would probably
just cause surprise, without being useful.
Cosmetic change to the init-time character eater (like, make it increment
the index counter - if there's a problem, it would sit there in an infinite
loop instead of only running 10 times).
Also, make sure we set %dx each time around otherwise the commands
suddenly start trying to work on things like com92 instead of com1.
Make sure comc_init() is only run once.
Cosmetic change to init-time character eater.
should be MD code since one day we'll have to recover pages from deleted
preload data. MI code can't be expected to know how to deal with pmap
internals, assuming it gets done via pmap that is. :-)
Do a much better job of DWIM with partial device specifications.
Fix the module metadata build process, which was completely broken.
Use a larger read buffer when copying large objects in; this
improves performance marginally and will avoid flushning any small caches
we might choose to implement.
Strip any device name information from the kernel name
before passing it in.
biosdisk.c
Be more strict about matching device names to slice entries.
Only allow unsliced syntax on unsliced disks.
Allocate space for, and copy, NDOSPART slice entries from the
MBR, not just one. Add some extra debugging while we're at it.
elf_freebsd.c
Initialise the symbol table start/end pointers in case we don't
have them.
Use bd_getdev() to work out a dev_t for the root device.
Allow $rootdev to override $currdev as the root device.
biosdisk.c
Save the slice table and disklabel when opening a disk.
Add bd_getdev(), which attempts to return a dev_t corresponding
to a given device. Cases which it still doesn't get right:
- The inevitable da-when-wd-also-exists
- Disks with no slice table (the slice number is not set correctly)
The first is difficult to get right, the second will be
fixed in an upcoming commit.
comconsole.c
vidconsole.c
getchar() should return an 8-bit value; some BIOSsen pack extra
information in %eax.
libi386.h
Remove some stale prototypes, add new ones.
of the ..umm.. "wierd" way binutils lays out the file. The section
headers are nearly at the end of the file and this is a problem when
loading from a .gz file which can't seek backwards (or has a limited
reverse seek, ~2K from memory).
This is intended to be compatable with the ddb/db_elf.c code and the
alpha/libalpha/elf_freebsd.c layout. I've studied these (which are NetBSD
derived) but did it a bit differently. Naturally the process is similar
since it's supposed to end up with the same result.
bootblocks, the kernel shows up as the primary module:
[3:24am]~-100# kldstat
Id Refs Address Size Name
1 1 0xf0100000 ff00000 /kernel
^^^^ oops.. :-)
Based heavily on aout_freebsd.c. Hmm.. There's so much in common that
these could probably be combined and just check the metadata to see which
format it is.
Presumably VTOP doesn't work for static objects.
The easiest way to get it working was to reserve some space after the
environment strings and copy the bootinfo struct there.
Also, set RB_BOOTINFO, it's needed.
I got the code to load and run an unmolested kernel OK for the first time
with this system a few minutes ago - at last!. I did have to stop it
looking at the floppy though as BTX was trapping a mode 14 fault when
it look for /boot/boot.conf when no disk was in the drive. (I'm booting
from a scsi disk (bios disk 0x80)).
Now to teach it about ELF and modules :-)
* Fix a raft of warnings, printf and otherwise.
* Allocate the correct amount in mod_searchmodule to prevent an overflow.
* Fix the makefiles so they work outside my home directory (oops).
- Make the "what do we do with a drunken disklabel" if-then-else-regardless
tangle easier to read.
- Don't count on the v86 structure being preserved between loop iterations,
as it may be trampled eg. by the DEBUG call.
- Discard large amounts of BIOS-related code in favour of the more compact
BTX vm86 interface.
- Build the loader module as ELF, although the resulting object is a.out,
make gensetdefs 32/64-bit sensitive and use a single copy of it.
- Throw away installboot, as it's no longer required.
- Use direct bcopy operations in the i386_copy module, as BTX
maps the first 16M of memory. Check operations against the
detected size of actual memory.
- Use format-independant module allocator.
- Conditionalise ISA PnP support.
- Simplify PnP enumerator interface.
- Improve module/object searching.
- Add missing depend/install targets in BTX makefiles.
- Pass the kernel environment and module data in extended bootinfo fields.
- Add a pointer to the end of the kernel + modules in bootinfo.
- Fix parsing of old-style kernel arguments.
- Move some startup code from MD to MI sections
- Add a 'copyout' and some copyout-related functions. These will be
obsoleted when BTX is available for the 386 and the kernel load
area becomes directly addressable.
- Add the ability load an arbitrary file as a module, associating
and arbitrary type string with it. This can be used eg. for loading
splash-screen images etc.
- Add KLD module dependancy infrastructure. We know how to look for
dependancies inside KLD modules, how to resolve these dependancies
and what to do if things go wrong. Only works for a.out at the
moment, due to lack of an MI ELF loader. Attach KLD module information
to loaded modules as metadata, but don't pass it to the kernel (it
can find it itself).
- Load a.out KLD modules on a page boundary. Only pad the a.out BSS
for the kernel, as it may want to throw symbols away. (We might want
to do this for KLD modules too.)
- Allow commands to be hidden from the '?' display, to avoid cluttering
it with things like 'echo'. Add 'echo'.
- Bring the 'prompt' command into line with the parser syntax.
- Fix the verbose 'ls'; it was using an uninitialised stack variable.
- Add a '-v' flag to 'lsmod' to have it display module metadata as well
(not terribly useful for the average user)
- Support a 'module searchpath' for required modules.
- The bootstrap file on i386 is now called 'loader' to permit the
/boot directory to use that name.
- Discard the old i386 pread() function, as it's replaced by
arch_readin()
- Implement a new copyin/readin interface for loading modules.
This allows the module loaders to become MI, reducing code duplication.
- Simplify the search for an image activator for the loaded kernel.
- Use the common module management code for all module metadata.
- Add an 'unload' command that throws everything away.
- Move the a.out module loader to MI code, add support for a.out
kld modules.
Submitted by: Alpha changes fixed by Doug Rabson <dfr@freebsd.org>
'three-stage' bootstrap.
There are a number of caveats with the code in its current state:
- The i386 bootstrap only supports booting from a floppy.
- The kernel and kld do not yet know how to deal with the extended
information and module summary passed in.
- PnP-based autodetection and demand loading of modules is not implemented.
- i386 ELF kernel loading is not ready yet.
- The i386 bootstrap is loaded via an ugly blockmap.
On the alpha, both net- and disk-booting (SRM console machines only) is
supported. No blockmaps are used by this code.
Obtained from: Parts from the NetBSD/i386 standalone bootstrap.
