Commit Graph

459 Commits (5220bdc5242877d8d6d457b5f4f6f5f3da78a833)

Author SHA1 Message Date
Michael Brown 5220bdc524 [legal] Add missing FILE_LICENCE declaration to efi_path.c
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-28 17:15:16 +00:00
Michael Brown 2fef0c541e [efi] Extend efi_locate_device() to allow searching up the device path
Extend the functionality of efi_locate_device() to allow callers to
find instances of the protocol that may exist further up the device
path.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-23 19:27:13 +00:00
Michael Brown 1cd0a248cc [efi] Add efi_path_prev() utility function
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-23 19:27:13 +00:00
Michael Brown 204d39222a [efi] Add efi_path_terminate() utility function
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-23 19:27:11 +00:00
Michael Brown 2dcef4b7a1 [efi] Create VLAN autoboot device automatically
When chainloading iPXE from an EFI VLAN device, configure the
corresponding iPXE VLAN device to be created automatically.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-15 22:42:30 +00:00
Michael Brown 5a2fa6040e [autoboot] Include VLAN tag in filter for identifying autoboot device
When chainloading iPXE from a VLAN device, the MAC address of the
loaded image's device handle will match the MAC address of the trunk
device created by iPXE, and the autoboot process will then erroneously
consider the trunk device to be an autoboot device.

Fix by recording the VLAN tag along with the MAC address, and treating
the VLAN tag as part of the filter used to match the MAC address
against candidate network devices.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-15 21:36:08 +00:00
Michael Brown 47af48012e [netdevice] Separate concept of scope ID from network device name index
The network device index currently serves two purposes: acting as a
sequential index for network device names ("net0", "net1", etc), and
acting as an opaque unique integer identifier used in socket address
scope IDs.

There is no particular need for these usages to be linked, and it can
lead to situations in which devices are named unexpectedly.  For
example: if a system has two network devices "net0" and "net1", a VLAN
is created as "net1-42", and then a USB NIC is connected, then the USB
NIC will be named "net3" rather than the expected "net2" since the
VLAN device "net1-42" will have consumed an index.

Separate the usages: rename the "index" field to "scope_id" (matching
its one and only use case), and assign the name without reference to
the scope ID by finding the first unused name.  For consistency,
assign the scope ID by similarly finding the first unused scope ID.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2023-01-14 00:09:20 +00:00
Michael Brown 60b5532cfc [cachedhcp] Include VLAN tag in filter for applying cached DHCPACK
When chainloading iPXE from a VLAN device, the MAC address within the
cached DHCPACK will match the MAC address of the trunk device created
by iPXE, and the cached DHCPACK will then end up being erroneously
applied to the trunk device.  This tends to break outbound IPv4
routing, since both the trunk and VLAN devices will have the same
assigned IPv4 address.

Fix by recording the VLAN tag along with the cached DHCPACK, and
treating the VLAN tag as part of the filter used to match the cached
DHCPACK against candidate network devices.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-12-22 14:59:29 +00:00
Michael Brown b9571ca12e [efi] Add efi_path_vlan() utility function
EFI provides no API for determining the VLAN tag (if any) for a
specified device handle.  There is the EFI_VLAN_CONFIG_PROTOCOL, but
that exists only on the trunk device handle (not on the VLAN device
handle), and provides no way to match VLAN tags against the trunk
device's child device handles.

The EDK2 codebase seems to rely solely on the device path to determine
the VLAN tag for a specified device handle: both NetLibGetVlanId() and
BmGetNetworkDescription() will parse the device path to search for a
VLAN_DEVICE_PATH component.

Add efi_path_vlan() which uses the same device path parsing logic to
determine the VLAN tag.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-12-22 14:27:56 +00:00
Michael Brown 099e4d39b3 [efi] Expose efi_path_next() utility function
Provide a single central implementation of the logic for stepping
through elements of an EFI device path.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-12-22 13:34:28 +00:00
Michael Brown 0f3ace92c6 [efi] Allow passing a NULL device path to path utility functions
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-12-22 13:30:02 +00:00
Michael Brown d879c8e4d9 [efi] Provide VLAN configuration protocol
UEFI implements VLAN support within the Managed Network Protocol (MNP)
driver, which may create child VLAN devices automatically based on
stored UEFI variables.  These child devices do not themselves provide
a raw-packet interface via EFI_SIMPLE_NETWORK_PROTOCOL, and may be
consumed only via the EFI_MANAGED_NETWORK_PROTOCOL interface.

The device paths constructed for these child devices may conflict with
those for the EFI_SIMPLE_NETWORK_PROTOCOL instances that iPXE attempts
to install for its own VLAN devices.  The upshot is that creating an
iPXE VLAN device (e.g. via the "vcreate" command) will fail if the
UEFI Managed Network Protocol has already created a device for the
same VLAN tag.

Fix by providing our own EFI_VLAN_CONFIG_PROTOCOL instance on the same
device handle as EFI_SIMPLE_NETWORK_PROTOCOL.  This causes the MNP
driver to treat iPXE's device as supporting hardware VLAN offload, and
it will therefore not attempt to install its own instance of the
protocol.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-12-14 11:51:52 +00:00
Michael Brown 7b60a48752 [efi] Clear DMA-coherent buffers before mapping
The DMA mapping is performed implicitly as part of the call to
dma_alloc().  The current implementation creates the IOMMU mapping for
the allocated and potentially uninitialised data before returning to
the caller (which will immediately zero out or otherwise initialise
the buffer).  This leaves a small window within which a malicious PCI
device could potentially attempt to retrieve firmware-owned secrets
present in the uninitialised buffer.  (Note that the hypothetically
malicious PCI device has no viable way to know the address of the
buffer from which to attempt a DMA read, rendering the attack
extremely implausible.)

Guard against any such hypothetical attacks by zeroing out the
allocated buffer prior to creating the coherent DMA mapping.

Suggested-by: Mateusz Siwiec <Mateusz.Siwiec@ioactive.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-11-04 20:28:09 +00:00
Michael Brown ff228f745c [pci] Generalise pci_num_bus() to pci_discover()
Allow pci_find_next() to discover devices beyond the first PCI
segment, by generalising pci_num_bus() (which implicitly assumes that
there is only a single PCI segment) with pci_discover() (which has the
ability to return an arbitrary contiguous chunk of PCI bus:dev.fn
address space).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-15 16:49:47 +01:00
Michael Brown 6459e3b7b1 [linux] Add missing PROVIDE_PCIAPI_INLINE() macros
Ensure type consistency of the PCI I/O API methods by adding the
missing PROVIDE_PCIAPI_INLINE() macros.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-09-15 15:20:58 +01:00
Michael Brown dd35475438 [efi] Support Unicode character output via framebuffer console
Extend the glyph cache to include a number of dynamic entries that are
populated on demand whenever a non-ASCII character needs to be drawn.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-15 17:30:52 +00:00
Michael Brown ba93c9134c [fbcon] Support Unicode character output
Accumulate UTF-8 characters in fbcon_putchar(), and require the frame
buffer console's .glyph() method to accept Unicode character values.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-15 17:27:18 +00:00
Michael Brown 2ff3385e00 [efi] Support Unicode character output via text console
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-03-15 17:09:58 +00:00
Michael Brown e1cedbc0d4 [console] Support AltGr to access ASCII characters via remapping
Several keyboard layouts define ASCII characters as accessible only
via the AltGr modifier.  Add support for this modifier to ensure that
all ASCII characters are accessible.

Experiments suggest that the BIOS console is likely to fail to
generate ASCII characters when the AltGr key is pressed.  Work around
this limitation by accepting LShift+RShift (which will definitely
produce an ASCII character) as a synonym for AltGr.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-15 12:50:26 +00:00
Michael Brown f2a59d5973 [console] Centralise handling of key modifiers
Handle Ctrl and CapsLock key modifiers within key_remap(), to provide
consistent behaviour across different console types.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-15 11:58:50 +00:00
Michael Brown 0979b3a11d [efi] Support keyboard remapping via the EFI console
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-02-10 13:11:27 +00:00
Michael Brown 6ba671acd9 [efi] Attempt to fetch autoexec script via TFTP
Attempt to fetch the autoexec.ipxe script via TFTP using the PXE base
code protocol installed on the loaded image's device handle, if
present.

This provides a generic alternative to the use of an embedded script
for chainloaded binaries, which is particularly useful in a UEFI
Secure Boot environment since it allows the script to be modified
without the need to sign a new binary.

As a side effect, this also provides a third method for breaking the
PXE chainloading loop (as an alternative to requiring an embedded
script or custom DHCP server configuration).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-18 13:16:12 +00:00
Michael Brown ec746c0001 [efi] Allow for autoexec scripts that are not located in a filesystem
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-18 13:16:12 +00:00
Michael Brown f43c2fd697 [settings] Support formatting UUIDs as little-endian GUIDs
The RFC4122 specification defines UUIDs as being in network byte
order, but an unfortunately significant amount of (mostly Microsoft)
software treats them as having the first three fields in little-endian
byte order.

In an ideal world, any server-side software that compares UUIDs for
equality would perform an endian-insensitive comparison (analogous to
comparing strings for equality using a case-insensitive comparison),
and would therefore not care about byte order differences.

Define a setting type name ":guid" to allow a UUID setting to be
formatted in little-endian order, to simplify interoperability with
server-side software that expects such a formatting.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2022-01-04 14:03:12 +00:00
Michael Brown 9062544f6a [efi] Disable EFI watchdog timer when shutting down to boot an OS
The UEFI specification mandates that the EFI watchdog timer should be
disabled by the platform firmware as part of the ExitBootServices()
call, but some platforms (e.g. Hyper-V) are observed to occasionally
forget to do so, resulting in a reboot approximately five minutes
after starting the operating system.

Work around these firmware bugs by disabling the watchdog timer
ourselves.

Requested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-25 09:30:59 +00:00
Michael Brown 562c74e1ea [efi] Run ExitBootServices shutdown hook at TPL_NOTIFY
On some systems (observed with the Thunderbolt ports on a ThinkPad X1
Extreme Gen3 and a ThinkPad P53), if the IOMMU is enabled then the
system firmware will install an ExitBootServices notification event
that disables bus mastering on the Thunderbolt xHCI controller and all
PCI bridges, and destroys any extant IOMMU mappings.  This leaves the
xHCI controller unable to perform any DMA operations.

As described in commit 236299b ("[xhci] Avoid DMA during shutdown if
firmware has disabled bus mastering"), any subsequent DMA operation
attempted by the xHCI controller will end up completing after the
operating system kernel has reenabled bus mastering, resulting in a
DMA operation to an area of memory that the hardware is no longer
permitted to access and, on Windows with the Driver Verifier enabled,
a STOP 0xE6 (DRIVER_VERIFIER_DMA_VIOLATION).

That commit avoids triggering any DMA attempts during the shutdown of
the xHCI controller itself.  However, this is not a complete solution
since any attached and opened USB device (e.g. a USB NIC) may
asynchronously trigger DMA attempts that happen to occur after bus
mastering has been disabled but before we reset the xHCI controller.

Avoid this problem by installing our own ExitBootServices notification
event at TPL_NOTIFY, thereby causing it to be invoked before the
firmware's own ExitBootServices notification event that disables bus
mastering.

This unsurprisingly causes the shutdown hook itself to be invoked at
TPL_NOTIFY, which causes a fatal error when later code attempts to
raise the TPL to TPL_CALLBACK (which is a lower TPL).  Work around
this problem by redefining the "internal" iPXE TPL to be variable, and
set this internal TPL to TPL_NOTIFY when the shutdown hook is invoked.

Avoid calling into an underlying SNP protocol instance from within our
shutdown hook at TPL_NOTIFY, since the underlying SNP driver may
attempt to raise the TPL to TPL_CALLBACK (which would cause a fatal
error).  Failing to shut down the underlying SNP device is safe to do
since the underlying device must, in any case, have installed its own
ExitBootServices hook if any shutdown actions are required.

Reported-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-23 15:55:01 +00:00
Michael Brown a046da21a4 [efi] Raise TPL during driver unload entry point
The efi_unload() function is currently missing the calls to raise and
restore the TPL.  This has the side effect of causing iPXE to return
from the driver unload entry point at TPL_CALLBACK, which will cause
unexpected behaviour (typically a system lockup) shortly afterwards.

Fix by adding the missing calls to raise and restore the TPL.

Debugged-by: Petr Borsodi <petr.borsodi@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-22 12:50:38 +00:00
Michael Brown b6045a8cbb [efi] Modify global system table when wrapping a loaded image
The EFI loaded image protocol allows an image to be provided with a
custom system table, and we currently use this mechanism to wrap any
boot services calls made by the loaded image in order to provide
strace-like debugging via DEBUG=efi_wrap.

The ExitBootServices() call will modify the global system table,
leaving the loaded image using a system table that is no longer
current.  When DEBUG=efi_wrap is used, this generally results in the
machine locking up at the point that the loaded operating system calls
ExitBootServices().

Fix by modifying the global EFI system table to point to our wrapper
functions, instead of providing a custom system table via the loaded
image protocol.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-21 13:34:10 +00:00
Michael Brown 51612b6e69 [efi] Do not attempt to use console output after ExitBootServices()
A successful call to ExitBootServices() will result in the EFI console
becoming unusable.  Ensure that the EFI wrapper produces a complete
line of debug output before calling the wrapped ExitBootServices()
method, and attempt subsequent debug output only if the call fails.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-11-21 13:24:24 +00:00
Michael Brown e09e1142a3 [efi] Record cached ProxyDHCPOFFER and PXEBSACK, if present
Commit cd3de55 ("[efi] Record cached DHCPACK from loaded image's
device handle, if present") added the ability for a chainloaded UEFI
iPXE to reuse an IPv4 address and DHCP options previously obtained by
a built-in PXE stack, without needing to perform a second DHCP
request.

Extend this to also record the cached ProxyDHCPOFFER and PXEBSACK
obtained from the EFI_PXE_BASE_CODE_PROTOCOL instance installed on the
loaded image's device handle, if present.

This allows a chainloaded UEFI iPXE to reuse a boot filename or other
options that were provided via a ProxyDHCP or PXE boot server
mechanism, rather than by standard DHCP.

Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-07-27 13:50:36 +01:00
Michael Brown 3c040ad387 [efi] Veto the Itautec Ip4ConfigDxe driver
The Ip4ConfigDxe driver bug that was observed on Dell systems in
commit 64b4452 ("[efi] Blacklist the Dell Ip4ConfigDxe driver") has
also been observed on systems with a manufacturer name of "Itautec
S.A.".  The symptoms of the bug are identical: an attempt to call
DisconnectController() on the LOM device handle will lock up the
system.

Fix by extending the veto to cover the Ip4ConfigDxe driver for this
manufacturer.

Debugged-by: Celso Viana <celso.vianna@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-06-11 15:14:21 +01:00
Michael Brown e5f0255173 [efi] Provide an "initrd.magic" file for use by UEFI kernels
Provide a file "initrd.magic" via the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
that contains the initrd file as constructed for BIOS bzImage kernels
(including injected files with CPIO headers constructed by iPXE).

This allows BIOS and UEFI kernels to obtain the exact same initramfs
image, by adding "initrd=initrd.magic" to the kernel command line.
For example:

  #!ipxe
  kernel boot/vmlinuz initrd=initrd.magic
  initrd boot/initrd.img
  initrd boot/modules/e1000.ko      /lib/modules/e1000.ko
  initrd boot/modules/af_packet.ko  /lib/modules/af_packet.ko
  boot

Do not include the "initrd.magic" file within the root directory
listing, since doing so would break software such as wimboot that
processes all files within the root directory.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-21 20:18:50 +01:00
Michael Brown ef9953b712 [efi] Allow for non-image-backed virtual files
Restructure the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL implementation to
allow for the existence of virtual files that are not simply backed by
a single underlying image.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-05-21 16:32:36 +01:00
Michael Brown 56f7d44fde [efi] Show ACPI address space descriptor ranges in debug messages
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-04-21 16:13:02 +01:00
Michael Brown 3efdbef2f0 [efi] Always map full length of coherent DMA buffer allocation
The EFI PCI API takes a page count as the input to AllocateBuffer()
but a byte count as the input to Map().  There is nothing in the UEFI
specification that requires us to map exactly the allocated length,
and no systems have yet been observed that will fail if the map length
does not exactly match the allocated length.  However, it is plausible
that some implementations may fail if asked to map a length that does
not match the length of the corresponding allocation.

Avoid potential future problems by always mapping the full allocated
length.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-04-20 14:37:08 +01:00
Michael Brown 614d99eba1 [xen] Avoid infinite loop on allocation failure in xenstore_response()
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-04-20 13:28:57 +01:00
Michael Brown 7c8fc2cae8 [linux] Fail at link time if building slirp.linux without libslirp
The iPXE build system is constructed for a standalone codebase with no
external dependencies, and does not have any equivalent of the
standard userspace ./configure script.  We currently check for the
ability to include slirp/libslirp.h and conditionalise portions of
linux_api.c on its presence.  The actual slirp driver code is built
unconditionally, as with all iPXE drivers.

This currently leads to a silent runtime failure if attempting to use
slirp.linux built on a system that was missing slirp/libslirp.h.

Convert this to a link-time failure by deliberately omitting the
relevant symbols from linux_api.c when slirp/libslirp.h is not
present.  This allows other builds (e.g. tap.linux or tests.linux) to
succeed: the link-time failure will occur only if the slirp driver is
included within the build target.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-11 15:25:33 +00:00
Michael Brown 65bd5c05db [linux] Do not assume that stat() works on sysfs files
Linux kernel 3.12 and earlier report a zero size via stat() for all
ACPI table files in sysfs.  There is no way to determine the file size
other than by reading the file until EOF.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-03 02:26:42 +00:00
Michael Brown 1c4917b6a7 [linux] Validate length of ACPI table read from sysfs
Consumers of acpi_find() will assume that returned structures include
a valid table header and that the length in the table header is
correct.  These assumptions are necessary when dealing with raw ACPI
tables, since there exists no independent source of length
information.

Ensure that these assumptions are also valid for ACPI tables read from
sysfs.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-03 01:55:07 +00:00
Michael Brown 69ecab2634 [linux] Use fstat() rather than statx()
The statx() system call has a clean header file and a consistent
layout, but was unfortunately added only in kernel 4.11.

Using stat() or fstat() directly is extremely messy since glibc does
not necessarily use the kernel native data structures.  However, as
the only current use case is to obtain the length of an open file, we
can merely provide a wrapper that does precisely this.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-03 01:01:58 +00:00
Michael Brown 2a2909cd1f [linux] Use generic sysfs mechanism to read SMBIOS table
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:48 +00:00
Michael Brown 6816006808 [linux] Use generic sysfs mechanism to read ACPI tables
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:46 +00:00
Michael Brown 5c8a9905ce [linux] Add a generic function for reading files from sysfs
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:30 +00:00
Michael Brown 976839ae4c [linux] Free cached ACPI tables on shutdown
Free any cached ACPI tables for the sake of neatness (and a clean
report from Valgrind).

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 23:59:27 +00:00
Michael Brown 3b8aff94bf [build] Fix building on older versions of gcc
Versions of gcc prior to 9.1 do not support the single-argument form
of static_assert().  Fix by unconditionally defining a compatibility
macro for the single file that uses this.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 16:47:22 +00:00
Michael Brown 2b5d3f582f [slirp] Add libslirp driver for Linux
Add a driver using libslirp to provide a virtual network interface
without requiring root permissions on the host.  This simplifies the
process of running iPXE as a Linux userspace application with network
access.  For example:

  make bin-x86_64-linux/slirp.linux
  ./bin-x86_64-linux/slirp.linux --net slirp

libslirp will provide a built-in emulated DHCP server and NAT router.
Settings such as the boot filename may be controlled via command-line
options.  For example:

  ./bin-x86_64-linux/slirp.linux \
      --net slirp,filename=http://192.168.0.1/boot.ipxe

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-02 11:09:57 +00:00
Michael Brown c09b627973 [linux] Provide ACPI settings via /sys/firmware/acpi/tables
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-01 01:38:54 +00:00
Michael Brown 9776f6ece1 [acpi] Allow for platforms that provide ACPI tables individually
The ACPI API currently expects platforms to provide access to a single
contiguous ACPI table.  Some platforms (e.g. Linux userspace) do not
provide a convenient way to obtain the entire ACPI table, but do
provide access to individual tables.

All iPXE consumers of the ACPI API require access only to individual
tables.

Redefine the internal API to make acpi_find() an API method, with all
existing implementations delegating to the current RSDT-based
implementation.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-03-01 00:08:23 +00:00
Michael Brown f309d7a7b7 [linux] Use host glibc system call wrappers
When building as a Linux userspace application, iPXE currently
implements its own system calls to the host kernel rather than relying
on the host's C library.  The output binary is statically linked and
has no external dependencies.

This matches the general philosophy of other platforms on which iPXE
runs, since there are no external libraries available on either BIOS
or UEFI bare metal.  However, it would be useful for the Linux
userspace application to be able to link against host libraries such
as libslirp.

Modify the build process to perform a two-stage link: first picking
out the requested objects in the usual way from blib.a but with
relocations left present, then linking again with a helper object to
create a standard hosted application.  The helper object provides the
standard main() entry point and wrappers for the Linux system calls
required by the iPXE Linux drivers and interface code.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-02-28 23:28:23 +00:00
Michael Brown cd3de55ea5 [efi] Record cached DHCPACK from loaded image's device handle, if present
Record the cached DHCPACK obtained from the EFI_PXE_BASE_CODE_PROTOCOL
instance installed on the loaded image's device handle, if present.

This allows a chainloaded UEFI iPXE to reuse the IPv4 address and DHCP
options previously obtained by the built-in PXE stack, as is already
done for a chainloaded BIOS iPXE.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-02-17 18:11:43 +00:00