Commit Graph

1287 Commits (79c0173d6df8580ea2e35fc173a5281e65d5321f)

Author SHA1 Message Date
Michael Brown 79c0173d6d [build] Create util/genfsimg for building filesystem-based images
Generalise util/geniso, util/gensdsk, and util/genefidsk to create a
single script util/genfsimg that can be used to build either FAT
filesystem images or ISO images.

Extend the functionality to allow for building multi-architecture UEFI
bootable ISO images and combined BIOS+UEFI images.

For example:

  ./util/genfsimg -o combined.iso \
      bin-x86_64-efi/ipxe.efi \
      bin-arm64-efi/ipxe.efi \
      bin/ipxe.lkrn

would generate a hybrid image that could be used as a CDROM (or hard
disk or USB key) on legacy BIOS, x86_64 UEFI, or ARM64 UEFI.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-01-13 17:58:02 +00:00
Michael Brown be1c87b722 [malloc] Rename malloc_dma() to malloc_phys()
The malloc_dma() function allocates memory with specified physical
alignment, and is typically (though not exclusively) used to allocate
memory for DMA.

Rename to malloc_phys() to more closely match the functionality, and
to create name space for functions that specifically allocate and map
DMA-capable buffers.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-05 19:13:52 +00:00
Michael Brown eecb75ba48 [pci] Update drivers to use pci_ioremap()
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-09-25 14:17:07 +01:00
Michael Brown 371af4eef2 [pci] Define pci_ioremap() for mapping PCI bus addresses
Define pci_ioremap() as a wrapper around ioremap() that could allow
for a non-zero address translation offset.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-09-24 21:45:56 +01:00
Dentcho Ludmilov Bankov 70b1a641c5 [comboot] Fix stack pointer retrieval after COM32 binary returns
This change fixes the offset used when retrieving the iPXE stack
pointer after a COM32 binary returns.  The iPXE stack pointer is saved
at the top of the available memory then the the top of the stack for
the COM32 binary is set just below it.  However seven more items are
pushed on the COM32 stack before the entry point is invoked so when
the COM32 binary returns the location of the iPXE stack pointer is 28
(and not 24) bytes above the current stack pointer.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-07-27 15:41:46 +01:00
David Decotigny 6ec33b8d6c [pcbios] Take alignment into account when checking for available space
Signed-off-by: David Decotigny <ddecotig@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-07-21 14:51:32 +01:00
David Decotigny 45a0ca6de2 [pcbios] Fix "out of memory" detection when expanding bottom area
This caused iPXE to reject images even when enough memory was
available.

Signed-off-by: David Decotigny <ddecotig@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-07-21 14:50:24 +01:00
Michael Brown 98d49e460a [efi] Avoid setting direction flag on EFI platforms
The only remaining use case in iPXE for the CPU direction flag is in
__memcpy_reverse() where it is set to allow the use of "rep movsb" to
perform the memory copy.  This matches the equivalent functionality in
the EDK2 codebase, which has functions such as InternalMemCopyMem that
also temporarily set the direction flag in order to use "rep movsb".

As noted in commit d2fb317 ("[crypto] Avoid temporarily setting
direction flag in bigint_is_geq()"), some UEFI implementations are
known to have buggy interrupt handlers that may reboot the machine if
a timer interrupt happens to occur while the direction flag is set.

Work around these buggy UEFI implementations by using the
(unoptimised) generic_memcpy_reverse() on i386 or x86_64 UEFI
platforms.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-07-07 14:08:05 +01:00
Michael Brown d2fb317fee [crypto] Avoid temporarily setting direction flag in bigint_is_geq()
The UEFI specification states that the calling convention for IA-32
and x64 includes "Direction flag in EFLAGS is clear".  This
specification covers only the calling convention used at the point of
calling functions annotated with EFIAPI.  The specification explicitly
states that other functions (such as private functions or static
library calls) are not required to follow the UEFI calling
conventions.

The reference EDK2 implementation follows this specification.  In
particular, the EDK2 interrupt handlers will clear the direction flag
before calling any EFIAPI functions, and will restore the direction
flag when returning from the interrupt handler.  Some EDK2 private
library functions (most notably InternalMemCopyMem) may set the
direction flag temporarily in order to make efficient use of CPU
string operations.

The current implementation of iPXE's bigint_is_geq() for i386 and
x86_64 will similarly set the direction flag temporarily in order to
make efficient use of CPU string operations.

On some UEFI implementations (observed with a Getac RX10 tablet), a
timer interrupt that happens to occur while the direction flag is set
will reboot the machine.  This very strongly indicates that the UEFI
timer interrupt handler is failing to clear the direction flag before
performing an affected operation (such as copying a block of memory).

Work around such buggy UEFI implementations by rewriting
bigint_is_geq() to avoid the use of string operations and so obviate
the requirement to temporarily set the direction flag.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-07-07 00:46:45 +01:00
Michael Brown decee20ec8 [build] Disable position-independent code for ARM64 EFI builds
Some versions of gcc (observed with the cross-compiling gcc 9.3.0 in
Ubuntu 20.04) default to enabling -fPIE.  Experimentation shows that
this results in the emission of R_AARCH64_ADR_GOT_PAGE relocation
records for __stack_chk_guard.  These relocation types are not
supported by elf2efi.c.

Fix by explicitly disabling position-independent code for ARM64 EFI
builds.

Debugged-by: Antony Messerli <antony@mes.ser.li>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-06-27 21:47:04 +01:00
Michael Brown efc1ae5aba [int13con] Create log partition only when CONSOLE_INT13 is enabled
Reduce the size of the USB disk image in the common case that
CONSOLE_INT13 is not enabled.

Originally-implemented-by: Romain Guyard <romain.guyard@mujin.co.jp>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-03-01 12:59:03 +00:00
Michael Brown 49319f1bc9 [bios] Define macros for constructing partition table entries
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-03-01 12:34:45 +00:00
Michael Brown c2226b3d1a [arm] Provide dummy implementations for {in,out}[s]{b,w,l}
It is currently not possible to build the all-drivers iPXE binaries
for ARM, since there is no implementation for inb(), outb(), etc.

There is no common standard for accessing I/O space on ARM platforms,
and there are almost no ARM-compatible peripherals that actually
require I/O space accesses.

Provide dummy implementations that behave as though no device is
present (i.e. ignore writes, return all bits high for reads).  This is
sufficient to allow the all-drivers binaries to link, and should cause
drivers to behave as though no I/O space peripherals are present in
the system.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2019-07-14 15:31:25 +01:00
Michael Brown 36a4c85f91 [init] Show startup and shutdown function names in debug messages
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2019-01-25 14:53:43 +00:00
Petr Borsodi ba0d5aa993 [pci] Correct invalid base-class/sub-class/prog-if order in PCIR
PCI Configuration Space contains fields prog-if at the offset 0x09,
sub-class at the offset 0x0a and base-class at the offset 0x0b (it
respects little endian).  PCIR structure uses these fields in the same
order.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2019-01-15 13:08:44 +00:00
Michael Brown d6f02c72c9 [undi] Include subsystem IDs in broken interrupt device check
Allow the subsystem IDs to be used when checking for PXE stacks with
broken interrupt support.

Suggested-by: Levi Hsieh <Levi.Hsieh@dell.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-04-18 16:57:05 +01:00
Michael Brown bc85368cdd [librm] Ensure that inline code symbols are unique
Commit 6149e0a ("[librm] Provide symbols for inline code placed into
other sections") may cause build failures due to duplicate label names
if the compiler chooses to duplicate inline assembly code.

Fix by using the "%=" special format string to include a
guaranteed-unique number within the label name.

The "%=" will be expanded only if constraints exist for the inline
assembly.  This fix therefore requires that all REAL_CODE() fragments
use a (possibly empty) constraint list.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-21 17:00:53 +02:00
Michael Brown 6149e0af3c [librm] Provide symbols for inline code placed into other sections
Provide symbols constructed from the object name and line number for
code fragments placed into alternative sections, such as inline
REAL_CODE() assembly placed into .text16.  This simplifies the
debugging task of finding the source code corresponding to a given
instruction pointer.

Note that we cannot use __FUNCTION__ since it is not a preprocessor
macro and so cannot be concatenated with string literals.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-21 14:44:04 +02:00
Michael Brown 0600ffeb30 [undi] Treat invalid IRQ numbers as non-fatal errors
If the underlying PXE stack reports an invalid IRQ number (above
IRQ_MAX), treat this as equivalent to an empty IRQ number and fall
back to using polling mode.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-21 10:28:05 +02:00
Michael Brown 1df3b53051 [build] Prevent use of MMX and SSE registers
The existence of MMX and SSE is required by the System V x86_64 ABI
and so is assumed by gcc, but these registers are not preserved by our
own interrupt handlers and are unlikely to be preserved by other
context switch handlers in a boot firmware environment.

Explicitly prevent gcc from using MMX or SSE registers to avoid
potential problems due to silent register corruption.

We must remove the %xmm0-%xmm5 clobbers from the x86_64 version of
hv_call() since otherwise gcc will complain about unknown register
names.  Theoretically, we should probably add code to explicitly
preserve the %xmm0-%xmm5 registers across a hypercall, in order to
guarantee to external code that these registers remain unchanged.  In
practice this is difficult since SSE registers are disabled by
default: for background information see commits 71560d1 ("[librm]
Preserve FPU, MMX and SSE state across calls to virt_call()") and
dd9a14d ("[librm] Conditionalize the workaround for the Tivoli VMM's
SSE garbling").

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-20 22:01:08 +02:00
Michael Brown 0d35411f88 [rng] Use fixed-point calculations for min-entropy quantities
We currently perform various min-entropy calculations using build-time
floating-point arithmetic.  No floating-point code ends up in the
final binary, since the results are eventually converted to integers
and asserted to be compile-time constants.

Though this mechanism is undoubtedly cute, it inhibits us from using
"-mno-sse" to prevent the use of SSE registers by the compiler.

Fix by using fixed-point arithmetic instead.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-20 20:56:01 +02:00
Michael Brown 3ec2079ce2 [time] Add support for the ACPI power management timer
Allow the ACPI power management timer to be used if enabled via
TIMER_ACPI in config/timer.h.  This provides an alternative timer on
systems where the standard 8254 PIT is unavailable or unreliable.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-20 17:26:49 +02:00
Michael Brown 89e31f8491 [librm] Add facility to provide register and stack dump for CPU exceptions
When DEBUG=librm_mgmt is enabled, intercept CPU exceptions and provide
a register and stack dump, then drop to an emergency shell.  Exiting
from the shell will almost certainly not work, but this provides an
opportunity to view the register and stack dump and carry out some
basic debugging.

Note that we can intercept only the first 8 CPU exceptions, since a
PXE ROM is not permitted to rebase the PIC.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-03-18 14:59:34 +02:00
Michael Brown 2bb4ec1f54 [build] Avoid use of "ld --oformat binary"
Using "ld --oformat binary" for mbr.bin and usbdisk.bin seems to cause
segmentation faults on some versions of binutils (observed on Fedora
27).  Work around this problem by using ld to create an intermediate
ELF object, followed by objcopy (via the existing %.tmp -> %.bin rule)
to create the final binary.

Note that we cannot simply use a single-stage "objcopy -O binary"
since this will not process the relocation records for x86_64: see
commit 1afcccd ("[build] Do not use "objcopy -O binary" for objects
with relocation records").

Reported-by: Brent S <bts@square-r00t.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2018-01-02 21:26:40 +01:00
Michael Brown 00c5b958c5 [legal] Add missing FILE_LICENCE declarations
Add missing FILE_LICENCE declarations to x86_64 headers based on the
corresponding i386 headers (from which the x86_64 headers were
originally derived).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-12-29 11:57:00 +00:00
Michael Brown 75acb3c775 [romprefix] Avoid unaligned accesses within ROM headers
Ensure that all headers (PCI, UNDI, PnP, iPXE) are aligned to at least
four bytes, so that all accesses to header fields will be correctly
aligned even when reading directly from the expansion ROM BAR.

Reported-by: Peter von Konigsmark <peter@exablaze.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-08-30 10:15:25 +01:00
Michael Brown 936657832f [hyperv] Do not steal ownership from the Gen 2 UEFI firmware
We must not steal ownership from the Gen 2 UEFI firmware, since doing
so will cause an immediate system crash (most likely in the form of a
reboot).

This problem was masked before commit a0f6e75 ("[hyperv] Do not fail
if guest OS ID MSR is already set"), since prior to that commit we
would always fail if we found any non-zero guest OS identity.  We now
accept a non-zero previous guest OS identity in order to allow for
situations such as chainloading from iPXE to another iPXE, and as a
prerequisite for commit b91cc98 ("[hyperv] Cope with Windows Server
2016 enlightenments").

A proper fix would be to reverse engineer the UEFI protocols exposed
within the Hyper-V Gen 2 firmware and use these to bind to the VMBus
device representing the network connection, (with the native Hyper-V
driver moved to become a BIOS-only feature).

As an interim solution, fail to initialise the native Hyper-V driver
if we detect the guest OS identity known to be used by the Gen 2 UEFI
firmware.  This will cause the standard all-drivers build (ipxe.efi)
to fall back to using the SNP driver.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-07-28 21:30:43 +01:00
Michael Brown 8866c919f8 [build] Fix ARM32 EFI builds with current EDK2 headers
EDK2 commit 6440385 ("MdePkg/Include: Add enumeration size checks to
Base.h") enforced the UEFI specification mandate that enums should
always be 32 bits.  This revealed a latent bug in iPXE, which does not
build with -fno-short-enums.

Fix by adding -fno-short-enums to CFLAGS for ARM32 EFI builds.

Reported-by: Benjamin S. Allen <bsallen@alcf.anl.gov>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-07-28 15:46:06 +01:00
Michael Brown b6fc8be2c4 [build] Conditionalise use of -mabi=lp64 for ARM64 builds
The -mabi option was added in GCC 4.9.  Test for the existence of this
option to allow for building with earlier versions of GCC.

Reported-by: Benjamin S. Allen <bsallen@alcf.anl.gov>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-07-28 12:49:40 +01:00
Michael Brown a6a5825f8d [cpuid] Allow input %ecx value to be specified
For some CPUID leaves (e.g. %eax=0x00000004), the result depends on
the input value of %ecx.  Allow this subfunction number to be
specified as a parameter to the cpuid() wrapper.

The subfunction number is exposed via the ${cpuid/...} settings
mechanism using the syntax

  ${cpuid/<subfunction>.0x40.<register>.<function>}

e.g.

  ${cpuid/0.0x40.0.0x0000000b}
  ${cpuid/1.0x40.0.0x0000000b}

to retrieve the CPU topology information.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-06-16 01:17:48 +01:00
Michael Brown 7c395b0e21 [build] Use -no-pie on newer versions of gcc
Some distributions patch gcc to generate position independent
executables by default.  We currently include a workaround to check
for this and to add -fno-PIE -nopie to CFLAGS if required.

Newer patched versions of gcc require -fno-PIE -no-pie instead.  Check
for both variants.

Reported-by: Nathan Rennie-Waldock <nathan.renniewaldock@gmail.com>
Originally-fixed-by: Markos Chandras <mchandras@suse.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-06-14 12:33:16 +01:00
Michael Brown 84e25513b1 [hdprefix] Avoid attempts to read beyond the end of the disk
When booting from a hard disk image (e.g. bin/ipxe.usb) within an
emulator such as QEMU, the disk may not exist beyond the end of the
image.  Limit all reads to the length of the image to avoid spurious
errors when loading the iPXE image.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-06-14 12:14:54 +01:00
Michael Brown 933e6dadc0 [acpi] Make acpi_find_rsdt() a per-platform method
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-05-23 18:34:39 +01:00
Michael Brown b91cc983da [hyperv] Cope with Windows Server 2016 enlightenments
An "enlightened" external bootloader (such as Windows Server 2016's
winload.exe) may take ownership of the Hyper-V connection before all
INT 13 operations have been completed.  When this happens, all VMBus
devices are implicitly closed and we are left with a non-functional
network connection.

Detect when our Hyper-V connection has been lost (by checking the
SynIC message page MSR).  Reclaim ownership of the Hyper-V connection
and reestablish any VMBus devices, without disrupting any existing
iPXE state (such as IPv4 settings attached to the network device).

Windows Server 2016 will not cleanly take ownership of an active
Hyper-V connection.  Experimentation shows that we can quiesce by
resetting only the SynIC message page MSR; this results in a
successful SAN boot (on a Windows 2012 R2 physical host).  Choose to
quiesce by resetting (almost) all MSRs, in the hope that this will be
more robust against corner cases such as a stray synthetic interrupt
occurring during the handover.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-04-28 16:20:47 +01:00
Michael Brown 276d618ca9 [hyperv] Remove redundant return status code from mapping functions
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-04-28 16:20:35 +01:00
Michael Brown a0f6e75532 [hyperv] Do not fail if guest OS ID MSR is already set
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-04-26 20:15:39 +01:00
Michael Brown dd976cb50d [block] Provide sandev_read() and sandev_write() as global symbols
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-04-26 20:15:39 +01:00
Michael Brown 84d406ccf4 [block] Allow use of a non-default EFI SAN boot filename
Some older operating systems (e.g. RHEL6) use a non-default filename
on the root disk and rely on setting an EFI variable to point to the
bootloader.  This does not work when performing a SAN boot on a
machine where the EFI variable is not present.

Fix by allowing a non-default filename to be specified via the
"sanboot --filename" option or the "san-filename" setting.  For
example:

  sanboot --filename \efi\redhat\grub.efi \
          iscsi:192.168.0.1::::iqn.2010-04.org.ipxe.demo:rhel6

or

  option ipxe.san-filename code 188 = string;
  option ipxe.san-filename "\\efi\\redhat\\grub.efi";
  option root-path "iscsi:192.168.0.1::::iqn.2010-04.org.ipxe.demo:rhel6";

Originally-implemented-by: Vishvananda Ishaya Abrams <vish.ishaya@oracle.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-04-12 15:58:05 +01:00
Michael Brown 5f85cbb9ee [build] Avoid implicit-fallthrough warnings on GCC 7
Reported-by: Vinson Lee <vlee@freedesktop.org>
Reported-by: Liang Yan <lyan@suse.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-29 10:36:45 +03:00
Michael Brown 7cfdd769aa [block] Describe all SAN devices via ACPI tables
Describe all SAN devices via ACPI tables such as the iBFT.  For tables
that can describe only a single device (i.e. the aBFT and sBFT), one
table is installed per device.  For multi-device tables (i.e. the
iBFT), all devices are described in a single table.

An underlying SAN device connection may be closed at the time that we
need to construct an ACPI table.  We therefore introduce the concept
of an "ACPI descriptor" which enables the SAN boot code to maintain an
opaque pointer to the underlying object, and an "ACPI model" which can
build tables from a list of such descriptors.  This separates the
lifecycles of ACPI descriptions from the lifecycles of the block
device interfaces, and allows for construction of the ACPI tables even
if the block device interface has been closed.

For a multipath SAN device, iPXE will wait until sufficient
information is available to describe all devices but will not wait for
all paths to connect successfully.  For example: with a multipath
iSCSI boot iPXE will wait until at least one path has become available
and name resolution has completed on all other paths.  We do this
since the iBFT has to include IP addresses rather than DNS names.  We
will commence booting without waiting for the inactive paths to either
become available or close; this avoids unnecessary boot delays.

Note that the Linux kernel will refuse to accept an iBFT with more
than two NIC or target structures.  We therefore describe only the
NICs that are actually required in order to reach the described
targets.  Any iBFT with at most two targets is therefore guaranteed to
describe at most two NICs.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-28 19:12:48 +03:00
Michael Brown c73af29fe2 [int13con] Avoid overwriting random portions of SAN boot disks
The INT13 console type (CONSOLE_INT13) autodetects at initialisation
time a magic partition to be used for logging iPXE console output.  If
the INT13 drive number mapping is subsequently changed (e.g. because
iPXE was used to perform a SAN boot), then the console logging output
will be written to the incorrect disk.

Fix by recording the INT13 vector at initialisation time, and using
this original vector to emulate INT13 calls for all subsequent
accesses.  This should be robust against drive remapping performed
either by ourselves or by another bootloader (e.g. a chainloaded
undionly.kpxe which then performs a SAN boot).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-27 10:50:59 +03:00
Michael Brown ebceb8ad8a [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>
2017-03-26 21:03:50 +03:00
Michael Brown bb5a54b79a [block] Add basic multipath support
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>
2017-03-26 16:06:02 +03:00
Michael Brown 7495813792 [video_subr] Use memmove() for overlapping memory copy
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-22 15:13:06 +02:00
Michael Brown d25e7daf47 [librm] Fail gracefully if asked to ioremap() a zero length
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-21 14:17:18 +02:00
Michael Brown 7692a8ff02 [undi] Move PXE API caller back into UNDI driver
As of commit 10d19bd ("[pxe] Always retrieve cached DHCPACK and apply
to relevant network device"), the UNDI driver has been the only user
of pxeparent_call().  Remove the unnecessary layer of abstraction by
refactoring this code back into undinet.c, and fix the ability of
undiisr.S to fall back to chaining to the original handler if we were
unable to unhook our own ISR.

This effectively reverts commit 337e1ed ("[pxe] Separate parent PXE
API caller from UNDINET driver").

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-19 15:57:24 +00:00
Michael Brown e790366c7c [int13] Refactor to use centralised SAN device abstraction
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2017-03-07 13:40:35 +00:00
Michael Brown e7ee2eda4b [block] Centralise "san-drive" setting
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>
2017-03-07 13:40:35 +00:00
Michael Brown f8cf3ceb0b [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>
2017-01-26 09:45:19 +00:00
Michael Brown fcf7751565 [int13] Avoid potential division by zero
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>
2017-01-26 09:31:40 +00:00