[int13] Improve geometry guessing for unaligned partitions
Some partition tables have partitions that are not aligned to a
cylinder boundary, which confuses the current geometry guessing logic.
Enhance the existing logic to ensure that we never reduce our guesses
for the number of heads or sectors per track, and add extra logic to
calculate the exact number of sectors per track if we find a partition
that starts within cylinder zero.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add basic support for multipath block devices. The "sanboot" and
"sanhook" commands now accept a list of SAN URIs. We open all URIs
concurrently. The first connection to become available for issuing
block device commands is marked as the active path and used for all
subsequent commands; all other connections are then closed. Whenever
the active path fails, we reopen all URIs and repeat the process.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The concept of the SAN drive number is meaningful only in a BIOS
environment, where it represents the INT13 drive number (0x80 for the
first hard disk). We retain this concept in a UEFI environment to
allow for a simple way for iPXE commands to refer to SAN drives.
Centralise the concept of the default drive number, since it is shared
between all supported environments.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Test correct return status from INT 13 calls
INT 13 calls return a status value via %ah, with CF set if %ah is
non-zero (indicating an error). Our wrappers zero the whole of %ax if
CF is clear, to allow C code (which has no easy access to CF) to
simply test for a non-zero status to detect an error.
The current code assigns the returned status to a uint8_t, effectively
testing %al rather than %ah. Fix by treating the returned status as a
uint16_t instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Avoid using a zero sector count to guess the disk geometry, since that
would result in a division by zero when calculating the number of
cylinders.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Allow default drive to be specified via "san-drive" setting
The DHCP option 175.189 has been defined (by us) since 2006 as
containing the drive number to be used for a SAN boot, but has never
been automatically used as such by iPXE.
Use this option (if specified) to override the default SAN drive
number.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Allow drive to be hooked using the natural drive number
Interpret the maximum drive number (0xff for hard disks, 0x7f for
floppy disks) as meaning "use natural drive number".
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Move most arch/i386 files to arch/x86, and adjust the contents of the
Makefiles and the include/bits/*.h headers to reflect the new
locations.
This patch makes no substantive code changes, as can be seen using a
rename-aware diff (e.g. "git show -M5").
This patch does not make the pcbios platform functional for x86_64; it
merely allows it to compile without errors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Using __from_text16() and __from_data16() in inline asm constraints
sometimes defeats gcc's ability to simplify expressions down to
compile-time constants.
Reported-by: Jason Kohles <jkohles@palantir.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Provide a permanently closed window via the control interface
Allow objects to support both streaming and block device protocols, by
starting streaming data only when the data transfer window opens.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Catch INT 13,4b when no explicit drive number is present
This allows older versions of ELTORITO.SYS (such as the version found
on the FreeDOS installation CD-ROM) to use iPXE's emulated CD-ROM
drive.
Reported-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expose the multiple-SAN-drive capability of the iPXE core via the iPXE
command line by adding commands to hook and unhook additional drives.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Automatically reopen underlying block device as needed
We currently use INT 13,00 as an opportunity to reopen the underlying
block device, which works well for callers such as DOS that will use
INT 13,00 in response to any disk errors. However, some callers (such
as Windows Server 2008) do not attempt to reset the disk, and so any
failures become effectively permanent.
Fix this by automatically reopening the underlying block device
whenever we might want to access it.
This makes direct installation of Windows to an iSCSI target much more
reliable.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Remove the concept of shutdown exit flags, and replace it with a
counter used to keep track of exposed interfaces that require devices
to remain active.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Include disk signature in debugging output
The disk signature is used by some OSes (notably Windows) to identify
the boot disk, so it's useful debugging information to have.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Add infrastructure to support EDD version 4.0
Support the extensions mandated by EDD 4.0, including:
o the ability to specify a flat physical address in a disk address
packet,
o the ability to specify a sector count greater than 127 in a disk
address packet,
o support for all functions within the Fixed Disk Access and EDD
Support subsets,
o the ability to describe a device using EDD Device Path Information.
This implementation is based on draft revision 3 of the EDD 4.0
specification, with reference to the EDD 3.0 specification. It is
possible that this implementation may need to change in order to
conform to the final published EDD 4.0 specification.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[block] Replace gPXE block-device API with an iPXE asynchronous interface
The block device interface used in gPXE predates the invention of even
the old gPXE data-transfer interface, let alone the current iPXE
generic asynchronous interface mechanism. Bring this old code up to
date, with the following benefits:
o Block device commands can be cancelled by the requestor. The INT 13
layer uses this to provide a global timeout on all INT 13 calls,
with the result that an unexpected passive failure mode (such as
an iSCSI target ACKing the request but never sending a response)
will lead to a timeout that gets reported back to the INT 13 user,
rather than simply freezing the system.
o INT 13,00 (reset drive) is now able to reset the underlying block
device. INT 13 users, such as DOS, that use INT 13,00 as a method
for error recovery now have a chance of recovering.
o All block device commands are tagged, with a numerical tag that
will show up in debugging output and in packet captures; this will
allow easier interpretation of bug reports that include both
sources of information.
o The extremely ugly hacks used to generate the boot firmware tables
have been eradicated and replaced with a generic acpi_describe()
method (exploiting the ability of iPXE interfaces to pass through
methods to an underlying interface). The ACPI tables are now
built in a shared data block within .bss16, rather than each
requiring dedicated space in .data16.
o The architecture-independent concept of a SAN device has been
exposed to the iPXE core through the sanboot API, which provides
calls to hook, unhook, boot, and describe SAN devices. This
allows for much more flexible usage patterns (such as hooking an
empty SAN device and then running an OS installer via TFTP).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
pcbios specific get_memmap() is used by the b44 driver making
all-drivers builds fail on other platforms. Move it to the I/O API
group and provide a dummy implementation on EFI.
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[int13] Guard against BIOSes that "fix" the drive count
Some BIOSes (observed with an AMI BIOS on a SunFire X2200) seem to
reset the BIOS drive counter at 40:75 after a failed boot attempt.
This causes problems when attempting a Windows direct-to-iSCSI
installation: bootmgr.exe calls INT 13,0800 and gets told that there
are no hard disks, so never bothers to read the MBR in order to obtain
the boot disk signature. The Windows iSCSI initiator will detect the
iBFT and connect to the target, and everything will appear to work
except for the error message "This computer's hardware may not support
booting to this disk. Ensure that the disk's controller is enabled in
the computer's BIOS menu."
Fix by checking the BIOS drive counter on every INT 13 call, and
updating it whenever necessary.
[int13] Pairwise swap drive numbers, instead of shifting all drive numbers
Shifting all INT13 drive numbers causes problems on systems that use a
sparse drive number space (e.g. qemu BIOS, which uses 0xe0 for the CD-ROM
drive).
The strategy now is:
Each drive is assigned a "natural" drive number, being the next
available drive number in the system (based on the BIOS drive count).
Each drive is accessed using its specified drive number. If the
specified drive number is -1, the natural drive number will be used.
Accesses to the specified drive number will be delivered to the
emulated drive, masking out any preexisting drive using this number.
Accesses to the natural drive number, if different, will be remapped to
the masked-out drive.
The overall upshot is that, for examples:
System has no drives. Emulated INT13 drive gets natural number 0x80
and specified number 0x80. Accesses to drive 0x80 go to the emulated
drive, and there is no remapping.
System has one drive. Emulated INT13 drive gets natural number 0x81
and specified number 0x80. Accesses to drive 0x80 go to the emulated
drive. Accesses to drive 0x81 get remapped to the original drive 0x80.
Michael Brown