booting because the CD driver did not use bounce buffers to ensure
request buffers sent to the BIOS were always in the first 1MB. Copy over
the bounce buffer logic from the BIOS disk driver (minus the 64k boundary
code for floppies) to fix this.
Reported by: kensmith
in make.conf or src.conf.
- When GPT is enabled (which it is by default), use memory above 1 MB and
leave the memory from the end of the bss to the end of the 640k window
purely for the stack. The loader has grown and now it is much more
common for the heap and stack to grow into each other when both are
located in the 640k window.
PR: kern/129526
MFC after: 1 week
the disklabel in the 2nd sector for boot code. Even with both UFS1
and UFS2 supported, there's enough bytes left that we don't have to
nibble from the disklabel.
Thus, the entire 2nd sector is now reserved for the disklabel, which
makes the bootcode compatible again with disklabels that have more
than 8 partitions -- such as those created and supported by gpart.
i386: 135 bytes available
amd64: 151 bytes available
Ok'd by: jhb
The old BTX passed the general purpose registers from the 32-bit client to
the routines called via virtual 86 mode. The new BTX did the same thing.
However, it turns out that some instructions behave differently in virtual 86
mode and real mode (even though this is under-documented). For example, the
LEAVE instruction will cause an exception in real mode if any of the upper
16-bits of %ebp are non-zero after it executes. In virtual 8086 mode the
upper 16-bits are simply ignored. This could cause faults in hardware
interrupt handlers that inherited an %ebp larger than 0xffff from the 32-bit
client (loader, boot2, etc.) while running in real mode.
To fix, when executing hardware interrupt handlers provide an explicit clean
state where all the general purpose and segment registers are zero upon
entry to the interrupt handler. While here, I attempted to simplify the
control flow in the 'intusr' code that sets up the various stack frames
and exits protected mode to invoke the requested routine via real mode.
A huge thanks to Tor Egge (tegge@) for debugging this issue.
Submitted by: tegge
Reviewed by: tegge
Tested by: bz
MFC after: 1 week
and re-enable it as default.
In particular:
+ re-enable the 'update' flag in the Makefile (of course!);
+ commit Warner's patch "orb $NOUPDATE,_FLAGS(%bp)"
to avoid writing to disk in case of a timeout/default choice;
+ fix an off-by-one count in the partition scan code that would
print the wrong name for unknown partitions;
+ unconditionally change the boot prompt to 'Boot:' instead of 'Default:'
to make room for the extra code/checks/messages. Some of the changes
listed below are also made to save space;
+ rearrange and fix comments for known partition types. Right now we
explicitly recognise *BSD, Linux, FAT16 (type 6, used on many USB keys),
NTFS (type 7), FAT32 (type 11).
Depending on other options we also recognise Extended (type 5),
FAT12 (type 1) and FAT16 < 32MB (type 4).
+ Add an entry "F6 PXE" when the code is built with -DPXE (which is
a default now). Technically, F6 boots through INT18, so the prompt 'PXE'
is a bit misleading. Unfortunately the name INT18
is too long and does not fit in - we could use ROM perhaps.
The reason I picked 'PXE' is that on many (I believe) new systems
INT18 calls PXE.
Apart from the choice of the name for PXE/ROM/INT18, this should close
pending issues on the 1-sector boot0 code and we should be able to
move the code to RELENG_7 when it reopens.
No boot0cfg changes are necessary.
MFC after: 3 weeks
boot0.S changes:
+ import a patch from Christoph Mallon to rearrange the various
print functions and save another couple of bytes;
+ implement the suggestion in PR 70531 to enable booting from
any valid partition because even the extended partitions that
were previously in our kill list may contain a valid boot loader.
This simplifies the code and saves some bytes;
+ followwing up PR 127764, implement conditional code to preserve
the 'Volume ID' which might be used by other OS (NT, XP, Vista)
and is located at offset 0x1b8. This requires a relocation of the
parameter block within the boot sector -- there is no other
possible workaround.
To address this, boot0cfg has been updated to handle both
versions of the boot code;
+ slightly rearrange the strings printed in the menus to make
the code buildable with all options. Given the tight memory
budget, this means that with certain options we need to
shrink or remove certain labels.
and especially:
make -DVOLUME_LABEL -DPXE the default options.
This means that the newly built boot0 block will preserve the
Volume ID, and has the (hidden) option F6 to boot from INT18/PXE.
I think the extra functionality is well worth the change.
The most visible difference here is that the 'Default: ' string
now becomes 'Boot: ' (it can be reverted to the old value
but then we need to nuke 1/2 partition name or entries to
make up for the extra room).
boot0cfg changes:
+ modify the code to recognise the new boot0 structure (with the
relocated options block to make room for the Volume id).
+ add two options, '-i xxxx-xxxx' to set the volume ID, -e c
to modify the character printed in case of bad input
PR: 127764 70531
Submitted by: Christoph Mallon (portions)
MFC after: 4 weeks
of the boot0.S code, with a number of compile-time selectable options,
the most interesting one being the ability to select PXE booting.
The code is completely compatible with the previous one, and with
the boot0cfg program. Even the actual code is largely unmodified,
with only minor rearrangements or fixes to make room for the new
features.
The behaviour of the standard build differs from the previous
version in the following, minor things:
+ 'noupdate' is the default, which means the code does not
write back the selection to disk. You can enable the feature
at runtime with boot0cfg, or changing the flags in the Makefile.
+ a drive number of 0x00 (floppy, or USB in floppy emulation) is
now accepted as valid. Previously, it was overridden with 0x80,
meaning that the partition table coming from the media was
used to access sectors on a possibly different media.
You can revert to the previous mode building with -DCHECK_DRIVE,
and you can always use the 'setdrv' option in boot0cfg
+ certain FAT or NTFS partitions are listed as WIN instead of DOS.
+ the 'bel' character on a bad selection is replaced by a '#' to
make it clear that the system is not hang even if the machine
does not have a speaker. This can be reverted back at compile
time, or at runtime with an upcoming boot0cfg option.
Additional features are available as compile time options,
and may be become the default if deemed useful. In particular:
+ INT18/PXE boot (make -DPXE)
This option enables booting through INT 18h (which on certain
BIOSes can be hooked to PXE) by pressing F6. There is unfortunately
no room to print the additional menu option.
Also, to make room for the code, the 'Default: ' string is
changed to 'Boot: '
+ print current drive number (make -DTEST)
Prints a line indicating the current drive number.
This is useful to figure out what is going on for machines/bioses
which remap drives in sometimes surprising ways.
+ disable numeric keys in console mode (make -DONLY_F_KEYS)
Not really a significant option, but it is needed to make
room for the -DTEST mode.
+ disable floppy support (make -DCHECK_DRIVE)
Revert to the old behaviour of only accepting 0x80 and above
as valid drive numbers.
MFC after: 6 weeks
instead of "puts" which prints whatever is at %si, followed by a CRLF.
It was not noticed during tests because at that point %si points
to a partition entry whose first byte is 0x80, which is both a
terminator for the string and a non printable character.
Submitted by: Christoph Mallon
boot code. The bug was introduced in rev.1.13, and went unnoticed
because FreeBSD's boot1 does not use it, but other systems might.
(I have been struggling for almost a full day trying to figure out
why a syslinux'ed partition would not boot when started with the
FreeBSD /boot/boot0, only to realize that the bug was ours!)
The space for the two extra bytes (push %si and pop %si) is reclaimed
by removing an extra CRLF that is printed before booting.
The bug is not a major one but if there is time it might be a good
thing to merge it into the upcoming releases.
to gptboot, i.e. installed in a freebsd-boot partition using /sbin/gpart or
/sbin/gpt.
Tweak the /boot/loader ZFS support so that it can find ZFS pools that are
contained in GPT partitions.
This bring huge amount of changes, I'll enumerate only user-visible changes:
- Delegated Administration
Allows regular users to perform ZFS operations, like file system
creation, snapshot creation, etc.
- L2ARC
Level 2 cache for ZFS - allows to use additional disks for cache.
Huge performance improvements mostly for random read of mostly
static content.
- slog
Allow to use additional disks for ZFS Intent Log to speed up
operations like fsync(2).
- vfs.zfs.super_owner
Allows regular users to perform privileged operations on files stored
on ZFS file systems owned by him. Very careful with this one.
- chflags(2)
Not all the flags are supported. This still needs work.
- ZFSBoot
Support to boot off of ZFS pool. Not finished, AFAIK.
Submitted by: dfr
- Snapshot properties
- New failure modes
Before if write requested failed, system paniced. Now one
can select from one of three failure modes:
- panic - panic on write error
- wait - wait for disk to reappear
- continue - serve read requests if possible, block write requests
- Refquota, refreservation properties
Just quota and reservation properties, but don't count space consumed
by children file systems, clones and snapshots.
- Sparse volumes
ZVOLs that don't reserve space in the pool.
- External attributes
Compatible with extattr(2).
- NFSv4-ACLs
Not sure about the status, might not be complete yet.
Submitted by: trasz
- Creation-time properties
- Regression tests for zpool(8) command.
Obtained from: OpenSolaris
boot an amd64 kernel. If not, then fail the boot request with an error
message. Otherwise, the boot attempt will fail with a BTX fault when
trying to read the EFER MSR.
MFC after: 3 days
set the %eflags used during a BIOS call via BTX to 0x202. Previously
the flags field was uninitialized garbage, and thus it was "random" if
interrupts were enabled or not during BIOS calls.
- Use constants from <machine/psl.h> for fields in %eflags.
MFC after: 3 days
- I had errantly assumed that all user requests should run with interrupts
enabled. User requests for software interrupts, however, need to disable
interrupts (and tracing) just like hardware interrupts.
- Disable alignment checking when emulating a hardware interrupt as well
(based on the description of the real mode operation of the 'INT'
instruction in the IA-32 manuals).
- Use constants for fields in %eflags.
Tested by: bz
MFC after: 3 days
commit, calling i386_parsedev(..., X, ...) where X is "ad", "bge", or
any other disk or network device name without a unit number, would
result in dereferencing whatever happened to be on the stack where the
variable "cp" is stored.
Found by: LLVM/Clang Static Checker
- It is opt-out for now so as to give it maximum testing, but it may be
turned opt-in for stable branches depending on the consensus. You
can turn it off with WITHOUT_SSP.
- WITHOUT_SSP was previously used to disable the build of GNU libssp.
It is harmless to steal the knob as SSP symbols have been provided
by libc for a long time, GNU libssp should not have been much used.
- SSP is disabled in a few corners such as system bootstrap programs
(sys/boot), process bootstrap code (rtld, csu) and SSP symbols themselves.
- It should be safe to use -fstack-protector-all to build world, however
libc will be automatically downgraded to -fstack-protector because it
breaks rtld otherwise.
- This option is unavailable on ia64.
Enable GCC stack protection (aka Propolice) for kernel:
- It is opt-out for now so as to give it maximum testing.
- Do not compile your kernel with -fstack-protector-all, it won't work.
Submitted by: Jeremie Le Hen <jeremie@le-hen.org>
libi386's time(), caused by a qemu bug. The bug might
be present in other BIOSes, too.
qemu either does not simulate the AT RTC correctly or
has a broken BIOS 1A/02 implementation, and will return
an incorrect value if the RTC is read while it is being
updated.
The effect is worsened by the fact that qemu's INT 15/86
function ("wait" a.k.a. usleep) is non-implmeneted or
broken and returns immediately, causing beastie.4th to
spin in a tight loop calling the "read RTC" function
millions of times, triggering the problem quickly.
Therefore, we keep reading the BIOS value until we get
the same result twice. This change fixes beastie.4th's
countdown under qemu.
Approved by: des (mentor)
entry in the SMAP is a 20 byte structure and they are queried from the
BIOS via sucessive BIOS calls. Due to an apparent bug in the R900's
BIOS, for some SMAP requests the BIOS overflows the 20 byte buffer
trashing a few bytes of memory immediately after the SMAP structure. As
a workaround, add 8 bytes of padding after the SMAP structure used in
the loader for SMAP queries.
PR: i386/122668
Submitted by: Mike Hibler mike flux.utah.edu, silby
MFC after: 3 days
routines (V86 requests from the client and hardware interrupt handlers):
- Install trampoline real mode interrupt handlers at IDT vectors 0x20-0x2f
to handle hardware interrupts by invoking the appropriate vector (0x8-0xf
or 0x70-0x78). This allows the 8259As to use vectors 0x20-0x2f in real
mode as well as protected mode will ensuring that the master 8259A
doesn't share IDT space with CPU exceptions in protected mode.
- Since we don't need to reserve space for page tables and a page directory
anymore since dropping paging support, move the TSS and protected mode
IDT up by 16k. Grow the ring 1 link stack by 16k as a result.
- Repurpose the ring 1 link stack to be used as a real mode stack when
invoking real mode routines either via a V86 request or a hardware
interrupts. This simplifies a few things as we avoid disturbing the
original user stack.
- Add some more block comments to explain how the code interacts with the
V86 structure as this wasn't immediately obvious from the prior comments
(e.g. that we explicitly copy the seg regs for real mode out of the V86
struct onto the stack to be popped off when going into real mode, etc.).
Also, document some of the stack frames we create going to real mode and
back.
- Remove all of the virtual 86 related code including having to simulate
various instructions and BIOS calls on a trap from virtual 86 mode.
- Explicitly panic if a user client attempts to perform a V86 CALL
request that isn't a far call.
- Bump version to 1.2.
Assuming this works ok this should fix some of the long standing issues
with USB booting as well as etherboot.
MFC after: 2 weeks
Submitted by: kib (some parts from his original real mode patch)
- Consolidate the code to humanize the size of a disk partition into a
single function based on the code for GPT partitions and use it for
GPT partitions, BSD slices, and BSD partitions.
- Teach the humanize code to use KB for small partitions (e.g. GPT boot
partitions now show up as 64KB rather than 0MB).
- Pad a few partition type names out so that things line up in the
common case.
MFC after: 1 week
weren't displayed on the new console. However, the config string has been
altered as part of being parsed so we only display the first option. Fix
this by saving a copy of /boot.config before parsing it and displaying the
saved copy after parsing.
MFC after: 1 week
PR: i386/103972
Submitted by: Alexandre Belloni alexandre.belloni of netasq.com
Enhanced Disk Drive Specification Ver 3.0 defines that the version
of extension in AH would be 30h.
Correct the check for that to be >=30h instead of >3h.
MFC after: 2 months
defined. This lets each boot program choose which version of cgbase() it
wants to use rather than forcing ufsread.c to have that knowledge.
MFC after: 1 week
Discussed with: imp
on i386 and amd64 machines. The overall process is that /boot/pmbr lives
in the PMBR (similar to /boot/mbr for MBR disks) and is responsible for
locating and loading /boot/gptboot. /boot/gptboot is similar to /boot/boot
except that it groks GPT rather than MBR + bsdlabel. Unlike /boot/boot,
/boot/gptboot lives in its own dedicated GPT partition with a new
"FreeBSD boot" type. This partition does not have a fixed size in that
/boot/pmbr will load the entire partition into the lower 640k. However,
it is limited in that it can only be 545k. That's still a lot better than
the current 7.5k limit for boot2 on MBR. gptboot mostly acts just like
boot2 in that it reads /boot.config and loads up /boot/loader. Some more
details:
- Include uuid_equal() and uuid_is_nil() in libstand.
- Add a new 'boot' command to gpt(8) which makes a GPT disk bootable using
/boot/pmbr and /boot/gptboot. Note that the disk must have some free
space for the boot partition.
- This required exposing the backend of the 'add' function as a
gpt_add_part() function to the rest of gpt(8). 'boot' uses this to
create a boot partition if needed.
- Don't cripple cgbase() in the UFS boot code for /boot/gptboot so that
it can handle a filesystem > 1.5 TB.
- /boot/gptboot has a simple loader (gptldr) that doesn't do any I/O
unlike boot1 since /boot/pmbr loads all of gptboot up front. The
C portion of gptboot (gptboot.c) has been repocopied from boot2.c.
The primary changes are to parse the GPT to find a root filesystem
and to use 64-bit disk addresses. Currently gptboot assumes that the
first UFS partition on the disk is the / filesystem, but this algorithm
will likely be improved in the future.
- Teach the biosdisk driver in /boot/loader to understand GPT tables.
GPT partitions are identified as 'disk0pX:' (e.g. disk0p2:) which is
similar to the /dev names the kernel uses (e.g. /dev/ad0p2).
- Add a new "freebsd-boot" alias to g_part() for the new boot UUID.
MFC after: 1 month
Discussed with: marcel (some things might still change, but am committing
what I have so far)
on duplicated code and support 64-bit LBAs for GPT.
- The code to manage an EDD or C/H/S I/O request are now in their own
routines. The EDD routine now handles a full 64-bit LBA instead of
truncating LBAs to the lower 32-bits. (MBRs and BSD labels only
have 32-bit LBAs anyway, so the only LBAs ever passed down were 32-bit).
- All of the bounce buffer and retry logic duplicated in bd_read() and
bd_write() are merged into a single bd_io() routine that takes an
extra direction argument. bd_read() and bd_write() are now simple
wrappers around bd_io().
- If a disk supports EDD then always use it rather than only using it if
the cylinder is > 1023. Other parts of the boot code already do
something similar to this. Also, GPT just uses LBAs, so for a GPT disk
it's probably best to ignore C/H/S completely. Always using EDD when
it is supported by a disk is an easy way to accomplish this.
MFC after: 1 week
macros to treat the 'slice' field as a real part of the bootdev instead
of as hack that spans two other fields (adaptor (sic) and controller)
that are not used in any modern FreeBSD boot code.
MFC after: 1 week
