[time] Allow system clock to be adjusted at runtime
Provide a mechanism to allow an arbitrary adjustment to be applied to
all subsequent calls to time().
Note that the underlying clock source (e.g. the RTC clock) will not be
changed; only the time as reported within iPXE will be affected.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
ARM64 has a weaker memory order model than x86. The missing memory
barrier caused phy initialization notification to be delayed beyond
the link-wait timeout (15 secs).
Signed-off-by: Leendert van Doorn <leendert@paramecium.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcp] Send TCP keepalives on idle established connections
In some circumstances, intermediate devices may lose state in a way
that temporarily prevents the successful delivery of packets from a
TCP peer. For example, a firewall may drop a NAT forwarding table
entry.
Since iPXE spends most of its time downloading files (and hence purely
receiving data, sending only TCP ACKs), this can easily happen in a
situation in which there is no reason for iPXE's TCP stack to generate
any retransmissions. The temporary loss of connectivity can therefore
effectively become permanent.
Work around this problem by sending TCP keepalives after a period of
inactivity on an established connection.
TCP keepalives usually send a single garbage byte in sequence number
space that has already been ACKed by the peer. Since we do not need
to elicit a response from the peer, we instead send pure ACKs (with no
garbage data) in order to keep the transmit code path simple.
Originally-implemented-by: Ladi Prosek <lprosek@redhat.com>
Debugged-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[pci] Support systems with multiple PCI root bridges
Extend the 16-bit PCI bus:dev.fn address to a 32-bit seg:bus:dev.fn
address, assuming a segment value of zero in contexts where multiple
segments are unsupported by the underlying data structures (e.g. in
the iBFT or BOFM tables).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[libc] Always use a non-zero seed for the (non-crypto) RNG
The non-cryptographic RNG implemented by random() has the property
that a seed value of zero will result in a generated sequence of
all-zero values. This situation can arise if currticks() returns zero
at start of day.
Work around this problem by falling back to a fixed non-zero seed if
necessary.
This has no effect on the separate DRBG used by cryptographic code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fix build error with perl >= 5.23.2:
Can't redeclare "my" in "my" at ./util/parserom.pl line 160
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Expose DHCP packets via the Apple NetBoot protocol
Mac OS X uses non-standard EFI protocols to obtain the DHCP packets
from the UEFI firmware.
Originally-implemented-by: Michael Kuron <m.kuron@gmx.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[dhcp] Fix definitions for x86_64 and EFI BC client architectures
There has been a longstanding disagreement between RFC4578 and the
IANA "Processor Architecture Types" registry. RFC4578 section 2.1
defines type 7 as "EFI BC" and type 9 as "EFI x86-64"; the IANA
registry quotes RFC4578 as its source but has these values erroneously
swapped. The EDK2 codebase uses the IANA values.
As of March 2016, RFC4578 has been modified by an errata to match the
values as recorded in the IANA registry.
Fix our definitions to match the consensus values.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some UEFI keyboard drivers are blissfully unaware of the existence of
either Ctrl key, and will report "Ctrl-<key>" as just "<key>". This
breaks substantial portions of the iPXE user interface.
Work around these broken UEFI drivers by allowing "ESC <key>" to be
used as a substitute for "Ctrl-<key>".
Tested-by: Dreamcat4 <dreamcat4@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some HTTP/2 servers send the header "Connection: upgrade, close". This
currently causes iPXE to fail due to the unrecognised "upgrade" token.
Fix by ignoring any unrecognised tokens in the "Connection" header.
Reported-by: Ján ONDREJ (SAL) <ondrejj@salstar.sk>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This backport is from linux kernel upstream commit 83d6f1f ("ath9k:
fix buffer overrun for ar9287").
Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The raw cycle counter at PMCCNTR_EL0 works in qemu but seems to always
read as zero on physical hardware (tested on Juno r1 and Cavium
ThunderX), even after ensuring that PMCR_EL0.E and PMCNTENSET_EL0.C
are both enabled.
Use CNTVCT_EL0 instead; this seems to count at a lower resolution
(tens of CPU cycles), but is usable for profiling.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Guard against GetStatus() failing to return a NULL TX buffer
The UEFI specification requires the EFI_SIMPLE_NETWORK_PROTOCOL
GetStatus() method to set TxBuf to NULL if there are no transmit
buffers to recycle.
Some implementations (observed with Lan9118Dxe in EDK2) fill in TxBuf
only when there is a transmit buffer to recycle, which leads to large
numbers of "spurious TX completion" errors.
Work around this problem by initialising TxBuf to NULL before calling
the GetStatus() method.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[libc] Avoid implicit assumptions about potentially-optimised memcpy()
Do not assume that an architecture-specific optimised memcpy() will
have the same properties as generic_memcpy() in terms of handling
overlapping regions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[arm] Avoid instruction references to symbols defined via ".equ"
When building for 64-bit ARM, some symbol references may be resolved
via an "adrp" instruction (to obtain the start of the 4kB page
containing the symbol) and a separate 12-bit offset. For example
(taken from the GNU assembler documentation):
adrp x0, foo
ldr x0, [x0, #:lo12:foo]
We occasionally refer to symbols defined via mechanisms that are not
directly visible to gcc. For example:
extern char some_magic_symbol[];
__asm__ ( ".equ some_magic_symbol, some_magic_expression" );
The subsequent use of the ":lo12:" prefix on such magically-defined
symbols triggers an assertion failure in the assembler.
This problem seems to affect only "private_key_len" in the current
codebase. Fix by storing this value as static data; this avoids the
need to provide the value as a literal within the instruction stream,
and so avoids the problematic use of the ":lo12:" prefix.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Use a timer event to generate the currticks() timer
We currently use the EFI_CPU_ARCH_PROTOCOL's GetTimerValue() method to
generate the currticks() timer, calibrated against a 1ms delay from
the boot services Stall() method.
This does not work on ARM platforms, where GetTimerValue() is an empty
stub which just returns EFI_UNSUPPORTED.
Fix by instead creating a periodic timer event, and using this event
to increment a current tick counter.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcpip] Do not fall back to using unoptimised TCP/IP checksumming
Require architecture-specific code to make a deliberate choice to use
the unoptimised generic_tcpip_continue_chksum() function, if there is
no optimised version available.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The dependency on zlib seems to have been introduced in commit 3dd7ce1
("[efi] Allow building with non-system libbfd") as an indirect
requirement of either libbfd or libiberty when building on Mac OS X.
Since we no longer use either of these libraries, remove the
unnecessary link against zlib.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Parse the intermediate ELF file directly instead of using libbfd, in
order to allow for cross-compiled ELF objects.
As a side bonus, this eliminates libbfd as a build requirement.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[librm] Preserve FPU, MMX and SSE state across calls to virt_call()
The IBM Tivoli Provisioning Manager for OS Deployment (also known as
TPMfOSD, Rembo-ia32, or Rembo Auto-Deploy) has a serious bug in some
older versions (observed with v5.1.1.0, apparently fixed by v7.1.1.0)
which can lead to arbitrary data corruption.
As mentioned in commit 87723a0 ("[libflat] Test A20 gate without
switching to flat real mode"), Tivoli's NBP sets up a VMM and makes
calls to the PXE stack in VM86 mode. This appears to be some kind of
attempt to run PXE API calls inside a sandbox. The VMM is fairly
sophisticated: for example, it handles our attempts to switch into
protected mode and patches our GDT so that our protected-mode code
runs in ring 1 instead of ring 0. However, it neglects to apply any
memory protections. In particular, it does not enable paging and
leaves us with 4GB segment limits. We can therefore trivially break
out of the sandbox by simply overwriting the GDT (or by modifying any
of Tivoli's VMM code or data structures).
When we attempt to execute privileged instructions (such as "lidt"),
the CPU raises an exception and control is passed to the Tivoli VMM.
This may result in a call to Tivoli's memcpy() function.
Tivoli's memcpy() function includes optimisations which use the SSE
registers %xmm0-%xmm3 to speed up aligned memory copies.
Unfortunately, the Tivoli VMM's exception handler does not save or
restore %xmm0-%xmm3. The net effect of this bug in the Tivoli VMM is
that any privileged instruction (such as "lidt") issued by iPXE may
result in unexpected corruption of the %xmm0-%xmm3 registers.
Even more unfortunately, this problem affects the code path taken in
response to a hardware interrupt from the NIC, since that code path
will call PXENV_UNDI_ISR. The net effect therefore becomes that any
NIC hardware interrupt (e.g. due to a received packet) may result in
unexpected corruption of the %xmm0-%xmm3 registers.
If a packet arrives while Tivoli is in the middle of using its
memcpy() function, then the unexpected corruption of the %xmm0-%xmm3
registers will result in unexpected corruption in the destination
buffer. The net effect therefore becomes that any received packet may
result in a 16-byte block of corruption somewhere in any data that
Tivoli copied using its memcpy() function.
We can work around this bug in the Tivoli VMM by saving and restoring
the %xmm0-%xmm3 registers across calls to virt_call(). To work around
the problem, we need to save registers before attempting to execute
any privileged instructions, and ensure that we attempt no further
privileged instructions after restoring the registers.
This is less simple than it may sound. We can use the "movups"
instruction to save and restore individual registers, but this will
itself generate an undefined opcode exception if SSE is not currently
enabled according to the flags in %cr0 and %cr4. We can't access %cr0
or %cr4 before attempting the "movups" instruction, because access a
control register is itself a privileged instruction (which may
therefore trigger corruption of the registers that we're trying to
save).
The best solution seems to be to use the "fxsave" and "fxrstor"
instructions. If SSE is not enabled, then these instructions may fail
to save and restore the SSE register contents, but will not generate
an undefined opcode exception. (If SSE is not enabled, then we don't
really care about preserving the SSE register contents anyway.)
The use of "fxsave" and "fxrstor" introduces an implicit assumption
that the CPU supports SSE instructions (even though we make no
assumption about whether or not SSE is currently enabled). SSE was
introduced in 1999 with the Pentium III (and added by AMD in 2001),
and is an architectural requirement for x86_64. Experimentation with
current versions of gcc suggest that it may generate SSE instructions
even when using "-m32", unless an explicit "-march=i386" or "-mno-sse"
is used to inhibit this. It therefore seems reasonable to assume that
SSE will be supported on any hardware that might realistically be used
with new iPXE builds.
As a side benefit of this change, the MMX register %mm0 will now be
preserved across virt_call() even in an i386 build of iPXE using a
driver that requires readq()/writeq(), and the SSE registers
%xmm0-%xmm5 will now be preserved across virt_call() even in an x86_64
build of iPXE using the Hyper-V netvsc driver.
Experimentation suggests that this change adds around 10% to the
number of cycles required for a do-nothing virt_call(), most of which
are due to the extra bytes copied using "rep movsb". Since the number
of bytes copied is a compile-time constant local to librm.S, we could
potentially reduce this impact by ensuring that we always copy a whole
number of dwords and so can use "rep movsl" instead of "rep movsb".
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown