[zbin] Fix check for existence of most recent output byte
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>
[zbin] Allow decompressor to generate debug output via BIOS console
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>
[prefix] Call decompressor in flat real mode when DEBUG=libprefix is enabled
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>
[zbin] Perform extra normalisation after completing decompression
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>
[prefix] Use .bss16 as temporary stack space for calls to install_block
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>
[timer] Rewrite the 8254 Programmable Interval Timer support
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>
[build] Apply the "-fno-PIE -nopie" workaround only to i386 builds
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>
[build] Use PRODUCT_SHORT_NAME for end-user visible strings
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>
[pxe] Maintain a queue for received PXE UDP packets
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>
[tftp] Explicitly abort connection whenever parent interface is closed
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>
[build] Use -malign-double to build 32-bit UEFI binaries
The EDK2 codebase uses -malign-double for 32-bit builds, which causes
64-bit integers to be naturally aligned. This affects the layout of
some structures (including EFI_BLOCK_IO_MEDIA).
This mirrors wimboot commit 7b8f39d ("[build] Fix building of 32-bit
UEFI version").
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[mromprefix] Allow for .mrom images larger than 128kB
The .mrom payload has a code type of 0xff and so the initialisation
length field (single byte at offset 0x02) does not need to be
present. Use only the PCI header's image length field, which allows
the .mrom payload to be up to 32MB in size.
Inspired-by: Swift Geek <swiftgeek@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[mromprefix] Use PCI length field to obtain length of individual images
mromprefix.S currently uses the initialisation length field (single
byte at offset 0x02) to determine the length of a ROM image within a
multi-image ROM BAR. For PCI ROM images with a code type other than
0, the initialisation length field may not be present.
Fix by using the PCI header's image length field instead.
Inspired-by: Swift Geek <swiftgeek@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The build process has for a long time assumed that every ROM is a PCI
ROM, and will always include the PCI header and PCI-related
functionality (such as checking the PCI BIOS version, including the
PCI bus:dev.fn address within the ROM product name string, etc.).
While real ISA cards are no longer in use, some virtualisation
environments (notably VirtualBox) have support only for ISA ROMs.
This can cause problems: in particular, VirtualBox will call our
initialisation entry point with random garbage in %ax, which we then
treat as the PCI bus:dev.fn address of the autoboot device: this
generally prevents the default boot sequence from using any network
devices.
Create .isarom and .pcirom prefixes which can be used to explicitly
specify the type of ROM to be created. (Note that the .mrom prefix
always implies a PCI ROM, since the .mrom mechanism relies on
reconfiguring PCI BARs.)
Make .rom a magic prefix which will automatically select the
appropriate PCI or ISA ROM prefix for ROMs defined via a PCI_ROM() or
ISA_ROM() macro. To maintain backwards compatibility, we default to
building a PCI ROM for anything which is not directly derived from a
PCI_ROM() or ISA_ROM() macro (e.g. bin/intel.rom).
Add a selection of targets to "make everything" to ensure that the
(relatively obscure) ISA ROM build process is included within the
per-commit QA checks.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Since some PnP BIOSes fail to set %es:di to point to the PnP signature
on entry, we identify a PnP BIOS by scanning through the top 64kB of
base memory looking for the PnP structure. We therefore don't
actually use the values of %es:di provided to the initialisation entry
point, and so there is no need to preserve them.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Using version 1 grant tables limits guests to using 16TB of grantable
RAM, and prevents the use of subpage grants. Some versions of the Xen
hypervisor refuse to allow the grant table version to be set after the
first grant references have been created, so the loaded operating
system may be stuck with whatever choice we make here. We therefore
currently use version 2 grant tables, since they give the most
flexibility to the loaded OS.
Current versions (7.2.0) of the Windows PV drivers have no support for
version 2 grant tables, and will merrily create version 1 entries in
what the hypervisor believes to be a version 2 table. This causes
some confusion.
Avoid this problem by attempting to use version 1 tables, since
otherwise we may render Windows unable to boot.
Play nicely with other potential bootloaders by accepting either
version 1 or version 2 grant tables (if we are unable to set our
requested version).
Note that the use of version 1 tables on a 64-bit system introduces a
possible failure path in which a frame number cannot fit into the
32-bit field within the v1 structure. This in turn introduces
additional failure paths into netfront_transmit() and
netfront_refill_rx().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xen] Accept alternative Xen platform PCI device ID 5853:0002
At some point during XenServer development history, the Windows PV
drivers changed to using a PCI device ID of 5853:0002 rather than
5853:0001. Current (7.2.0) drivers will bind to either 5853:0001 or
5853:0002, and the general approach taken by the world at large
(including Amazon EC2) seems to be to use only 5853:0001.
However, the current version of XenServer (6.2.0) will create the
platform device as 5853:0002 (via the platform:device_id VM parameter)
for any VMs created using the built-in templates for Windows Vista or
later.
Accept either PCI ID, since the underlying device is identical.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Default to releasing network devices for use via SNP
We currently treat network devices as available for use via the SNP
API only if RX queue processing has been frozen. (This is similar in
spirit to the way that RX queue processing is frozen for the network
device currently exposed via the PXE API.)
The default state of a freshly created network device is for the RX
queue to not be frozen, and thus to be unavailable for use via SNP.
This causes problems when devices are added through code paths other
than _efidrv_start() (which explicitly releases devices for use via
SNP).
We don't actually need to freeze RX queue processing, since calls via
the SNP API will always use netdev_poll() rather than net_poll(), and
so will never trigger the RX queue processing code path anyway.
We can therefore simplify the code to use a single global flag to
indicate whether network devices are claimed for use by iPXE or
available for use via SNP. Using a global flag allows the default
state for dynamically created network devices to behave sensibly.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add basic support for Xen PV-HVM domains (detected via the Xen
platform PCI device with IDs 5853:0001), including support for
accessing configuration via XenStore and enumerating devices via
XenBus.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ioapi] Fail ioremap() when attempting to map a zero bus address
When a 32-bit iPXE binary is running on a system which allocates PCI
memory BARs above 4GB, our PCI subsystem will return the base address
for any such BARs as zero (with a warning message if DEBUG=pci is
enabled). Currently, ioremap() will happily map an address pointing
to the start of physical memory, providing no sensible indication of
failure.
Fix by always returning NULL if we are asked to ioremap() a zero bus
address.
With a totally flat memory model (e.g. under EFI), this provides an
accurate failure indication since no PCI peripheral will be mapped to
the zero bus address.
With the librm memory model, there is the possibility of a spurious
NULL return from ioremap() if the bus address happens to be equal to
virt_offset. Under the current virtual memory map, the NULL virtual
address will always be the start of .textdata, and so this problem
cannot occur; a NULL return from ioremap() will always be an accurate
failure indication.
Debugged-by: Anton D. Kachalov <mouse@yandex-team.ru>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide a single instance of EFI_DRIVER_BINDING_PROTOCOL (attached to
our image handle); this matches the expectations scattered throughout
the EFI specification.
Open the underlying hardware device using EFI_OPEN_PROTOCOL_BY_DRIVER
and EFI_OPEN_PROTOCOL_EXCLUSIVE, to prevent other drivers from
attaching to the same device.
Do not automatically connect to devices when being loaded as a driver;
leave this task to the platform firmware (or to the user, if loading
directly from the EFI shell).
When running as an application, forcibly disconnect any existing
drivers from devices that we want to control, and reconnect them on
exit.
Provide a meaningful driver version number (based on the build
timestamp), to allow platform firmware to automatically load newer
versions of iPXE drivers if multiple drivers are present.
Include device paths within debug messages where possible, to aid in
debugging.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[librm] Allow for the PIC interrupt vector offset to be changed
Some external code (observed with FreeBSD's bootloader) will continue
to make INT 13 calls after reconfiguring the 8259 PIC to change the
vector offsets for IRQs. If an IRQ (e.g. the timer IRQ) subsequently
occurs while iPXE is in protected mode, this will cause a general
protection fault since the corresponding IDT entry is empty.
A general protection fault is INT 0x0d, which happens to overlap with
the original IRQ5. We therefore do have an ISR set up to handle a
general protection fault, but this ISR simply reflects the interrupt
down to the real-mode INT 0x0d and then attempts to return. Since our
ISR is expecting a hardware interrupt rather than a general protection
fault, it doesn't remove the error code from the stack before issuing
the iret instruction; it therefore attempts to return to a garbage
address. Since the segment part of this address is likely to be
invalid, a second general protection fault occurs. This cycle
continues until we run out of stack space and triple fault.
Fix by reflecting all INTs down to real mode. This actually reduces
the code size by four bytes (but increases the bss size by almost
2kB).
Reported-by: Brian Rak <dn@devicenull.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[lkrnprefix] Make real-mode setup code relocatable
The bzImage boot protocol allows the real-mode code to be loaded at
any segment within base memory. (The fact that both iPXE and recent
versions of Syslinux will load the real-mode code at 1000:0000 is a
coincidence; it is not guaranteed by the specification.)
Fix by making the code relocatable.
Reported-by: Andrew Stuart <andrew@shopcusa.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Rework geniso and genliso to provide a single merged utility for
generating ISO images.
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown