Use the standard "pushl $function ; pushw %cs ; call prot_call"
sequence everywhere that prot_call() is used.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
On a 64-bit CPU, any modification of a register by 32-bit or 16-bit
code will destroy the invisible upper 32 bits of the corresponding
64-bit register. For example: a 32-bit "pushl %eax" followed by a
"popl %eax" will zero the upper half of %rax. This differs from the
treatment of upper halves of 32-bit registers by 16-bit code: a
"pushw %ax" followed by a "popw %ax" will leave the upper 16 bits of
%eax unmodified.
Inline assembly generated using REAL_CODE() or PHYS_CODE() will
therefore have to preserve the upper halves of all registers, to avoid
clobbering registers that gcc expects to be preserved.
Output operands from REAL_CODE() and PHYS_CODE() assembly may
therefore contain undefined values in the upper 32 bits.
Fix by using explicit variable widths (e.g. uint32_t) for
non-discarded output operands, to ensure that undefined values in the
upper 32 bits of 64-bit registers are ignored.
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>
Commit c64747d ("[librm] Speed up real-to-protected mode transition
under KVM") rounded down the .text16 segment address calculated in
alloc_basemem() to a multiple of 64 bytes in order to speed up mode
transitions under KVM.
This creates a potential discrepancy between alloc_basemem() and
free_basemem(), meaning that free_basemem() may free less memory than
was allocated by alloc_basemem().
Fix by padding the calculated sizes of both .text16 and .data16 to a
multiple of 64 bytes at build time.
Debugged-by: Yossef Efraim <yossefe@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a debug function check_bios_interrupts() to look for changes
to the interrupt vector table. This can be useful when investigating
the behaviour (including crashes) of external PXE NBPs.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit 5de45cd ("[romprefix] Report a pessimistic runtime size
estimate") set the PCI3.0 "runtime size" field equal to the worst-case
runtime size, on the basis that there is no guarantee that PMM
allocation will succeed and hence no guarantee that we will be able to
shrink the ROM image.
On a PCI3.0 system where PMM allocation would succeed, this can cause
the BIOS to unnecessarily refuse to initialise the iPXE ROM due to a
perceived shortage of option ROM space.
Fix by reporting the best-case runtime size via the PCI header, and
checking that we have sufficient runtime space (if applicable). This
allows iPXE ROMs to initialise on PCI3.0 systems that might otherwise
fail due to a shortage of option ROM space.
This may cause iPXE ROMs to fail to initialise on PCI3.0 systems where
PMM is broken. (Pre-PCI3.0 systems are unaffected since there must
already have been sufficient option ROM space available for the
initialisation entry point to be called.)
On balance, it seems preferable to avoid breaking "good" systems
(PCI3.0 with working PMM) at the cost of potentially breaking "bad"
systems (PCI3.0 with broken PMM).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The GuestRPC mechanism (used for VMWARE_SETTINGS and CONSOLE_VMWARE)
does not use any real-mode code and so can be exposed in both 64-bit
and 32-bit builds.
Reported-by: Matthew Helton <mwhelton@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When USB network card drivers are used, the BIOS' legacy USB
capability is necessarily disabled since there is no way to share the
host controller between the BIOS and iPXE.
Commit 3726722 ("[usb] Add basic support for USB keyboards") added
support allowing a USB keyboard to be used within iPXE. However,
external code such as a PXE NBP has no way to utilise this support,
and so a USB keyboard cannot be used to control a PXE NBP loaded from
a USB network card.
Add support for injecting keypresses from any iPXE console into the
BIOS keyboard buffer. This allows external code such as a PXE NBP to
function with a USB keyboard even after the BIOS' legacy USB
capability has been disabled.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE does not call shutdown() before invoking a COMBOOT executable,
since the executable is allowed to make API calls back into iPXE. If
a background picture is used, then the console will not be restored to
text mode before invoking the COMBOOT executable. This can cause
undefined behaviour.
Fix by adding an explicit call to console_reset() immediately before
invoking a COMBOOT or COM32 executable, analogous to the call made to
console_reset() immediately before invokving a PXE NBP.
Debugged-by: Andrew Widdersheim <awiddersheim@inetu.net>
Tested-by: Andrew Widdersheim <awiddersheim@inetu.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The name "vesafb" is intrinsically specific to a BIOS environment.
Generalise the build configuration option CONSOLE_VESAFB to
CONSOLE_FRAMEBUFFER, in preparation for adding EFI framebuffer
support.
Existing configurations using CONSOLE_VESAFB will continue to work.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Use INT 1a,564e to notify the BIOS of each network device that we
detect. This provides an opportunity for the BIOS to implement
platform policy such as changing the MAC address by issuing a call to
PXENV_UNDI_SET_STATION_ADDRESS.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Invoke INT 1a,564e whenever a PXE stack is activated, passing the
address of the PXENV+ structure in %es:%bx. This is designed to allow
a BIOS to be notified when a PXE stack has been installed, providing
an opportunity for start-of-day commands such as setting the MAC
address according to a policy chosen by the BIOS.
PXE defines INT 1a,5650 as a means of locating the PXENV+ structure:
this call returns %ax=0x564e and the address of the PXENV+ structure
in %es:%bx. We choose INT 1a,564e as a fairly natural notification
call, using the parameters as would be returned by INT 1a,5650.
The full calling convention (documented as per section 3.1 of the PXE
specification) is:
INT 1a,564e - PXE installation notification
Enter:
%ax = 0x564e
%es = 16-bit segment address of the PXENV+ structure
%bx = 16-bit offset of the PXENV+ structure
Exit:
%edx may be trashed (as is the case for INT 1a,5650)
All other register contents must be preserved
CF is cleared
IF is preserved
All other flags are undefined
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Merge the functionality of parse_next_server_and_filename() and
tftp_uri() into a single pxe_uri(), which takes a server address
(IPv4/IPv6/none) and a filename, and produces a URI using the rule:
- if the filename is a hierarchical absolute URI (i.e. includes a
scheme such as "http://" or "tftp://") then use that URI and ignore
the server address,
- otherwise, if the server address is recognised (according to
sa_family) then construct a TFTP URI based on the server address,
port, and filename
- otherwise fail.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some distributions (observed with Ubuntu 15.04) place ldlinux.c32 in a
separate directory from isolinux.bin. Search for these files
separately, and allow an alternative location of ldlinux.c32 to be
provided via LDLINUX_C32=... on the make command line.
Reported-by: Adrian Koshka <adriankoshcha@teknik.io>
Tested-by: Adrian Koshka <adriankoshcha@teknik.io>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit edf74df ("[pxe] Always reconstruct packet for
PXENV_GET_CACHED_INFO") fixed the problems caused by returning stale
DHCP packets (e.g. from an earlier boot attempt using a different
network device), but broke interoperability with NBPs such as WDS
which may overwrite our cached (fake) DHCP packets and expect the
modified packets to be returned by a subsequent call to
PXENV_GET_CACHED_INFO.
Fix by constructing the fake DHCP packets immediately before
transferring control to a PXE NBP. Calls to PXENV_GET_CACHED_INFO
will now never modify the cached packets.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A relatively common user mistake is to attempt to boot an EFI
executable (such as grub.efi) using a BIOS version of iPXE.
Unfortunately there are no signature checks that we can use to
unambiguously identify a PXE NBP, since a PXE NBP is just raw machine
code. We therefore have to accept anything sufficiently small to fit
into base memory as a valid PXE NBP.
We can detect that a file might be an EFI executable by checking for
the initial "MZ" signature bytes. This does not necessarily preclude
the file from also being a PXE NBP (since it would be possible to
create a hybrid binary which acts as both an EFI executable and a PXE
NBP, similar to the way in which wimboot and the Linux kernel are
hybrid binaries which act as both an EFI executable and a bzImage).
If the initial "MZ" signature bytes are present, then attempt to warn
the user by setting the image type to "PXE-NBP (may be EFI?)". We
can't (sensibly) prevent the user from accidentally running an EFI
executable as a PXE NBP, but we can at least make it easier for the
user to identify their mistake.
Inspired-by: Robin Smidsrød <robin@smidsrod.no>
Inspired-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
UEFI platforms may provide a watchdog timer, which will reboot the
machine if an operating system takes more than five minutes to load.
This can cause long-lived iPXE downloads (or interactive shell
sessions) to unexpectedly reboot.
Fix by resetting the watchdog timer every ten seconds while the iPXE
main processing loop continues to run.
Reported-by: Bradley B Williams <bradleybwilliams@swbell.net>
Reported-by: John Clark <john.r.clark.3@gmail.com>
Reported-by: wdriever@gmail.com
Reported-by: Charlie Beima <cbeima@indiana.edu>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Check for existence of the UART in uart_select(), not just in
uart_init(). This allows uart_select() to refuse to set a non-working
address in uart->base, which in turns means that the serial console
code will not attempt to use a non-existent UART.
Reported-by: Torgeir Wulfsberg <Torgeir.Wulfsberg@kongsberg.com>
Reported-by: Ján ONDREJ (SAL) <ondrejj@salstar.sk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When the ability for iPXE to handle multiple serial ports was added,
the choice was made that the singular serial port referred to by
COMBOOT calls should mean the port used for the serial console. This
unintentionally caused IMAGE_COMBOOT to also enable CONSOLE_SERIAL.
Fix by providing a weak-symbol version of the serial console which
will be used if serial console support was not explicitly enabled.
Reported-by: Torgeir Wulfsberg <Torgeir.Wulfsberg@kongsberg.com>
Reported-by: Ján ONDREJ (SAL) <ondrejj@salstar.sk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We do not set up any kind of virtual addressing before invoking an
ELFBoot image. Reject if the image's program headers indicate that
virtual addresses are not equal to physical addresses.
This avoids problems when loading some RHEL5 kernels, which seem to
include ELFBoot headers using virtual addressing. With this change,
these kernels are no longer detected as ELFBoot, and so may be
(correctly) detected as bzImage instead.
Reported-by: Torgeir.Wulfsberg@kongsberg.com
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expose the high bit of the VGA text attribute byte via the ANSI SGR
parameters 5 ("blink on") and 25 ("blink off").
Note that some video cards (and virtual machines) may display a high
intensity background colour instead of blinking text.
Signed-off-by: Christian Nilsson <nikize@gmail.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Older, out-of-tree Xen kernel modules (such as those provided with
SuSE Linux Enterprise Server 11) do not clear the leftover "event
pending" bit when opening an event channel. Consequently, no event is
ever delivered to indicate that there is information in the XenStore
ring buffer, and the system hangs shortly after loading the
xen-platform-pci kernel module.
Work around this problem by always waiting for the XenStore event
channel to be signalled, and clearing the event before processing the
received data.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Avoid accidentally returning stale packets (e.g. for a previously
attempted network device) by always constructing a fresh DHCP packet.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The size of the .mrom payload (the second PCI ROM image) is defined in
its PCI header. The code type for the .mrom payload image is
deliberately set to an invalid value (0xff) to ensure that no BIOS
tries to parse anything in the image other than the PCI header.
Since the code type is not set to 0x00 ("Intel x86, PC-AT
compatible"), bytes 0x02-0x17 should not be interpreted by the BIOS as
being in the standard ISA expansion ROM format. In particular, the
byte at offset 0x02 does not represent the length of the ROM image (in
512-byte blocks).
However, some Dell BIOSes seem to erroneously use the byte at offset
0x02 to determine the length of the .mrom payload when walking the
list of PCI ROM images. Since this byte is currently set to zero,
this can lead to the BIOS getting stuck in an infinite loop during
POST. (This problem may not arise if the .mrom payload is the final
image in the ROM, since the BIOS will then have no reason to attempt
to locate the next image.)
One possible workaround would be to put the real payload size in this
byte, but doing so would constrain the .mrom payload size to 128kB
(see commit 8049a52 ("[mromprefix] Allow for .mrom images larger than
128kB") for more details).
Another possible workaround would be to put the real payload size as a
word in bytes 0x02-0x03 (as is done for EFI ROMs). This would not
constrain the .mrom payload size, but a payload size which happened to
be exactly 128kB would result in a zero value in the byte at offset
0x02 and so could still result in infinite loops on BIOSes with this
bug.
We choose to place a fixed value of 0x01 in the byte at offset 0x02.
This should at least prevent the BIOS from getting stuck in an
infinite loop. (The BIOS may walk into the middle of the .mrom
payload, where it will almost certainly not find a valid {0x55,0xaa}
signature or a valid PCIR header, and will therefore hopefully abort
processing.)
Reported-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some HP BIOSes (observed with an HP ProLiant m710p Server Cartridge)
have a bug in the implementation of INT 1a,b101: they blithely assume
that real-mode code is able to read from anywhere in the 32-bit memory
space.
This problem affects the call to INT 1a,b101 made from within
pcibios_num_bus() (which uses REAL_CODE() and hence executes in
genuine real mode) but does not affect the call made from within
romprefix.S (since with a PMM BIOS, that call executes in flat real
mode anyway).
Work around the problem by explicitly calling flatten_real_mode()
before invoking INT 1a,b101. This is a rarely-used code path, and so
the extra overhead of emulating instructions in some VM configurations
(see commit 6d4deee ("[librm] Use genuine real mode to accelerate
operation in virtual machines") for more details) is negligible.
Reported-by: Wissam Shoukair <wissams@mellanox.com>
Debugged-by: Wissam Shoukair <wissams@mellanox.com>
Debugged-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several popular public cloud providers do not provide any sensible
mechanism for obtaining debug output from an OS which is failing to
boot. For example, Amazon EC2 provides the "Get System Log" facility,
which occasionally deigns to report a random subset of the characters
emitted via the VM's serial port, but usually returns only a blank
screen. (Amazingly, this is still superior to the debugging
facilities provided by Azure.)
Work around these shortcomings by adding a console type which sends
output to a magically detected raw disk partition, and including such
a partition within any iPXE .usb-format image.
To use this facility:
- build an iPXE .usb image with CONSOLE_INT13 enabled
- boot the cloud VM from this image
- after the boot fails, attach the VM's boot disk to a second VM
- from this second VM, use "less -f -R /dev/sdb3" (or similar) to
view the iPXE output.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Rename PCI_CLASS() (which constructs a struct pci_class_id) to
PCI_CLASS_ID(), and provide PCI_CLASS() as a macro which constructs
the 24-bit scalar value of a PCI class code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The "vram" setting returns the (Base64-encoded) contents of video RAM,
and can be used to capture a screenshot. For example: after running
memtest.0 and encountering an error, the output can be captured and
sent to a remote server for later diagnosis:
#!ipxe
chain -a http://server/memtest.0 && goto ok || goto bad
:bad
params
param errno ${errno}
param vram ${vram}
chain -a http://server/report.php##params
:ok
Inspired-by: Christian Nilsson <nikize@gmail.com>
Originally-implemented-by: Christian Nilsson <nikize@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The USB bus drivers (ehci.c and xhci.c) have PCI device ID tables and
hence PCI_ROM() lines, but should probably not be included in the
all-drivers build on this basis, since they do nothing useful unless a
USB network driver is also present.
Fix by constructing the all-drivers list based on the driver class
(i.e. the portion of the source path immediately after "drivers/").
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The assembler on OpenBSD 5.7 seems not to correctly handle the
combinations of .struct and .previous used in unlzma.S, and ends up
complaining about an "attempt to allocate data in absolute section".
Work around this problem by explicitly resetting the section after the
data structure definitions.
Reported-by: Jiri B <jirib@devio.us>
Tested-by: Jiri B <jirib@devio.us>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
PCI v3.0 supports a "device list" which allows the ROM to claim
support for multiple PCI device IDs (but only a single vendor ID).
Add support for building such ROMs by scanning the build target
element list and incorporating any device IDs into the ROM's device
list header. For example:
make bin/8086153a--8086153b.mrom
would build a ROM claiming support for both 8086:153a and 8086:153b.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Entropy gathering via timer ticks is slow under UEFI (of the order of
20-30 seconds on some machines). Use the EFI_RNG_PROTOCOL if
available, to speed up the process of entropy gathering.
Note that some implementations (including EDK2) will fail if we
request fewer than 32 random bytes at a time, and that the RNG
protocol provides no guarantees about the amount of entropy provided
by a call to GetRNG(). We take the (hopefully pessimistic) view that
a 32-byte block returned by GetRNG() will contain at least the 1.3
bits of entropy claimed by min_entropy_per_sample().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Our current behaviour when booting as a ROM is to autoboot only from
devices which are attached via the PCI bus:dev.fn address passed to
the ROM's initialisation vector.
Add a build configuration option AUTOBOOT_ROM_FILTER (enabled by
default) to control this behaviour. This allows for ROMs to be built
which will attempt to boot from any detected device, even if not
attached via the original PCI bus:dev.fn address. (This is
particularly useful when building combined EHCI/xHCI ROMs for USB
network boot, since the BIOS may request a boot via the EHCI
controller but the xHCI driver will reroute the root hub ports to the
xHCI controller.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We hook the UEFI ExitBootServices() event and use it to trigger a call
to shutdown_boot(). This does not automatically cause drivers to be
disconnected from their devices, since device enumeration is now
handled by the UEFI core rather than by iPXE. (Under the old and
dubiously compatible device model, iPXE used to perform its own device
enumeration and so the call to shutdown_boot() would indeed have
caused drivers to be disconnected.)
Fix by replicating parts of the dummy "EFI root device" from
efiprefix.c to efidrvprefix.c, so that the call to shutdown_boot()
will call efi_driver_disconnect_all().
Originally-fixed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
None of the x86_64 builds currently have any way of invoking these
functions. They are included only to avoid introducing unnecessary
architecture-specific dependencies into the self-test suite.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Commit 8ab4b00 ("[libc] Rewrite setjmp() and longjmp()") introduced a
regression in which the saved values of %ebx, %esi, and %edi were all
accidentally restored into %esp. The result is that the second and
subsequent returns from setjmp() would effectively corrupt %ebx, %esi,
%edi, and the stack pointer %esp.
Use of setjmp() and longjmp() is generally discouraged: our only use
occurs as part of the implementation of PXENV_RESTART_TFTP, since the
PXE API effectively mandates its use here. The call to setjmp()
occurs at the start of pxe_start_nbp(), where there are almost
certainly no values held in %ebx, %esi, or %edi. The corruption of
these registers therefore had no visible effect on program execution.
The corruption of %esp would have been visible on return from
pxe_start_nbp(), but there are no known PXE NBPs which first call
PXENV_RESTART_TFTP and subsequently attempt to return to the PXE base
code. The effect on program execution was therefore similar to that
of moving the stack to a pseudo-random location in the 32-bit address
space; this will often allow execution to complete successfully since
there is a high chance that the pseudo-random location will be unused.
The regression therefore went undetected for around one month.
Fix by restoring the correct registers from the saved jmp_buf
structure.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several of the assembly files in arch/i386/prefix were missed by the
automated relicensing tool due to missing licence declarations, code
dating back to the initial git revision, etc. Manual review shows
that these files may be relicensed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Relicense files with kind permission from
Stefan Hajnoczi <stefanha@redhat.com>
alongside the contributors who have already granted such relicensing
permission.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
At some point in the past few years, binutils became more aggressive
at removing unused symbols. To function as a symbol requirement, a
relocation record must now be in a section marked with @progbits and
must not be in a section which gets discarded during the link (either
via --gc-sections or via /DISCARD/).
Update REQUIRE_SYMBOL() to generate relocation records meeting these
criteria. To minimise the impact upon the final binary size, we use
existing symbols (specified via the REQUIRING_SYMBOL() macro) as the
relocation targets where possible. We use R_386_NONE or R_X86_64_NONE
relocation types to prevent any actual unwanted relocation taking
place. Where no suitable symbol exists for REQUIRING_SYMBOL() (such
as in config.c), the macro PROVIDE_REQUIRING_SYMBOL() can be used to
generate a one-byte-long symbol to act as the relocation target.
If there are versions of binutils for which this approach fails, then
the fallback will probably involve killing off REQUEST_SYMBOL(),
redefining REQUIRE_SYMBOL() to use the current definition of
REQUEST_SYMBOL(), and postprocessing the linked ELF file with
something along the lines of "nm -u | wc -l" to check that there are
no undefined symbols remaining.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The valgrind headers are not x86-specific; they detect the CPU
architecture and contain inline assembly for multiple architectures.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
These files cannot be automatically relicensed by util/relicense.pl
since they either contain unusual but trivial contributions (such as
the addition of __nonnull function attributes), or contain lines
dating back to the initial git revision (and so require manual
knowledge of the code's origin).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Relicence files with kind permission from the following contributors:
Alex Williamson <alex.williamson@redhat.com>
Eduardo Habkost <ehabkost@redhat.com>
Greg Jednaszewski <jednaszewski@gmail.com>
H. Peter Anvin <hpa@zytor.com>
Marin Hannache <git@mareo.fr>
Robin Smidsrød <robin@smidsrod.no>
Shao Miller <sha0.miller@gmail.com>
Thomas Horsten <thomas@horsten.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The code in lzma_literal() checks to see if we are at the start of the
compressed input data in order to determine whether or not a most
recent output byte exists. This check is incorrect, since
initialisation of the decompressor will always consume the first five
bytes of the compressed input data.
Fix by instead checking whether or not we are at the start of the
output data stream. This is, in any case, a more logical check.
This issue was masked during development and testing since virtual
machines tend to zero the initial contents of RAM; the spuriously-read
"most recent output byte" is therefore likely to already be a zero
when running in a virtual machine.
Reported-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The 0xe9 debug port exists only on virtual machines. Provide an
option to print debug output on the BIOS console, to allow for
debugging on real hardware.
Note that this option can be used only if the decompressor is called
in flat real mode; the easiest way to achieve this is to build with
DEBUG=libprefix.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the decompressor the option of generating debugging output via
the BIOS console by calling it in flat real mode (rather than 16-bit
protected mode) when libprefix.S is built with debugging enabled.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
LZMA performs an extra normalisation after decompression is complete,
which does not affect the output but may consume an extra byte from
the input (and so may affect which byte is identified as being the
start of the next block).
Reported-by: Robin Smidsrød <robin@smidsrod.no>
Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
LZMA provides significantly better compression (by ~15%) than the
current NRV2B algorithm.
We use a raw LZMA stream (aka LZMA1) to avoid the need for code to
parse the LZMA2 block headers. We use parameters {lc=2,lp=0,pb=0} to
reduce the stack space required by the decompressor to acceptable
levels (around 8kB). Using lc=3 or pb=2 would give marginally better
compression, but at the cost of substantially increasing the required
stack space.
The build process now requires the liblzma headers to be present on
the build system, since we do not include a copy of an LZMA compressor
within the iPXE source tree. The decompressor is written from scratch
(based on XZ Embedded) and is entirely self-contained within the
iPXE source.
The branch-call-jump (BCJ) filter used to improve the compressibility
is specific to iPXE. We choose not to use liblzma's built-in BCJ
filter since the algorithm is complex and undocumented. Our BCJ
filter achieves approximately the same results (on typical iPXE
binaries) with a substantially simpler algorithm.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some decompression algorithms (e.g. LZMA) require large amounts of
temporary stack space, which may not be made available by all
prefixes. Use .bss16 as a temporary stack for the duration of the
calls to install_block (switching back to the external stack before we
start making calls into code which might access variables in .bss16),
and allow the decompressor to define a global symbol to force a
minimum value on the size of .bss16.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Other hypervisors (e.g. KVM) may provide an unusable subset of the
Hyper-V features, and our attempts to use these non-existent features
cause the guest to reboot.
Fix by explicitly checking for the Hyper-V features that we use.
Reported-by: Ján ONDREJ (SAL) <ondrejj@salstar.sk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The 8254 timer code (used to implement udelay()) has an unknown
provenance. Rewrite this code to avoid potential licensing
uncertainty.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As with memcpy(), we can reduce the code size (by an average of 0.2%)
by giving the compiler more visibility into what memset() is doing,
and by avoiding the "rep" prefix on short fixed-length sequences of
string operations.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some of the C library string functions have an unknown provenance.
Reimplement all such functions to avoid potential licensing
uncertainty.
Remove the inline-assembler versions of strlen(), memswap(), and
strncmp(); these save a minimal amount of space (around 40 bytes in
total) and are not performance-critical.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Hardened versions of gcc default to building position-independent
code, which breaks our i386 build. Our build process therefore
detects such platforms and automatically adds "-fno-PIE -nopie" to the
gcc command line.
On x86_64, we choose to build position-independent code (in order to
reduce the final binary size and, in particular, the number of
relocations required for UEFI binaries). The workaround therefore
breaks the build process for x86_64 binaries on such platforms.
Fix by moving the workaround to the i386-specific portion of the
Makefile.
Reported-by: Jan Kundrát <jkt@kde.org>
Debugged-by: Jan Kundrát <jkt@kde.org>
Debugged-by: Marin Hannache <git@mareo.fr>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Use PRODUCT_SHORT_NAME instead of a hardcoded "iPXE" for strings which
are typically shown in the user interface.
Note that this only allows for customisation of the user interface.
Where the "iPXE" string serves a technical purpose (such as in the
HTTP User-Agent), the string cannot be customised.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some devices return multiple packets in a single poll. Handle such
devices gracefully by enqueueing received PXE UDP packets (along with
a pseudo-header to hold the IPv4 addresses and port numbers) and
dequeueing them on subsequent calls to PXENV_UDP_READ.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fetching the TFTP file size is currently implemented via a custom
"tftpsize://" protocol hack. Generalise this approach to instead
close the TFTP connection whenever the parent data-transfer interface
is closed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow drivers to specify a supported PCI class code. To save space in
the final binary, make this an attribute of the driver rather than an
attribute of a PCI device ID list entry.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
