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>
[settings] Use list_first_entry() when unregistering child settings
Unregistering a child settings block can have almost arbitrary
effects, due to the call to apply_settings(). Avoid potentially
dereferencing a stale pointer by using list_first_entry() rather than
list_for_each_entry_safe() to iterate over the list of child settings.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The code in list.h was originally taken from the Linux kernel many
years ago, but has been rewritten to the point that no original code
remains, and may therefore be relicensed.
The functions and data structures remain largely API-compatible, to
facilitate the conversion of Linux network drivers to iPXE.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
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>
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
Relicense files authored by Dan Lynch while working as an employee of
Fen Systems Ltd., with permission from Fen Systems Ltd.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The UBDL relicensing tool (util/relicense.pl) is designed to identify
files which may be relicensed under a dual GPL+UBDL licence. It uses
git-blame to identify the author of each line (using the -M and -C
options to track lines moved or copied between files), and relicenses
files for which all authors have given permission.
The relicensing tool will ignore certain types of lines identified by
git-blame:
- empty lines
- comments
- standalone opening or closing braces
- "#include ..."
- "return 0;"
- "return rc;"
- "PCI_ROM(...)"
- "FILE_LICENCE(...)"
These lines either contain no meaningful content (e.g. empty lines),
contain only non-copyrightable facts (e.g. PCI ROM IDs) or are
sufficiently common within the codebase that git-blame is likely to
misattribute their origin (e.g. "return 0").
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Add support for the Unmodified Binary Distribution Licence
Add the text for the Unmodified Binary Distribution Licence. This
Licence allows for the distribution of unmodified binaries built from
publicly available source code, without imposing the obligations of
the GNU General Public License upon anyone who chooses to distribute
only the unmodified binaries built from that source code. See the
licence text for the precise terms and conditions.
Add the licence GPL2_OR_LATER_OR_UBDL to the set of licences which can
be declared using FILE_LICENCE(), and add the corresponding support to
licence.pl.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Include full licence text for all GPL2_OR_LATER files
Add the standard warranty disclaimer and Free Software Foundation
address paragraphs to the licence text where these are not currently
present.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[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>
[dhcp] Extract timing parameters out to config/dhcp.h
iPXE uses DHCP timeouts loosely based on values recommended by the
specification, but often abbreviated to reduce timeouts for reliable
and/or simple network topologies. Extract the DHCP timing parameters
to config/dhcp.h and document them. The resulting default iPXE
behavior is exactly the same, but downstreams are now afforded the
opportunity to implement spec-compliant behavior via config file
overrides.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Modified-by: Michael Brown <mcb30@ipxe.org>
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>
The implementation of strtoul() has a partially unknown provenance.
Rewrite this code to avoid potential licensing uncertainty.
Since we now use -ffunction-sections, there is no need to place
strtoull() in a separate file from strtoul().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The implementation of inet_aton() has an unknown provenance. Rewrite
this code to avoid potential licensing uncertainty.
Also move the code from core/misc.c to its logical home in net/ipv4.c,
and add a few extra test cases.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When a command times out, abort it (via the Command Abort bit in the
Command Ring Control Register) so that subsequent commands may execute
as expected.
This improves robustness when a device fails to respond to the Set
Address command, since the subsequent Disable Slot command will now
succeed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Leak memory if controller fails to disable slot
If the Disable Slot command fails then the hardware may continue to
write to the slot context. Leak the memory used by the slot context
to avoid future memory corruption.
This situation has been observed in practice when a Set Address
command fails, causing the command ring to become temporarily
unresponsive.
Note that there is no need to similarly leak memory on the failure
path in xhci_device_open(), since in the event of a failure the
hardware is never informed of the slot context address.
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>
Michael Brown