[efi] Use the EFI_RNG_PROTOCOL as an entropy source if available
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>
[efi] Poll for TX completions only when there is an outstanding TX buffer
At least one NII implementation (in a Microsoft Surface tablet) seems
to fail to report the absence (sic) of TX completions properly. Work
around this by checking for TX completions only when we expect to see
one.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Poll media status only if advertised as supported
Some NII implementations will fail the GET_STATUS operation if we
request the media status. Fix by doing so only if GET_INIT_INFO
reported that media status is supported.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[romprefix] Allow autoboot device filter to be disabled
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>
In theory USB3 ports do not require a reset to enable the port.
Experimentation shows that this is sometimes required, particularly
when rerouting ports from EHCI to xHCI and switching speeds.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[build] Rewrite parserom.pl to support multiple source files
Running util/parserom.pl on all source files (637) one by one takes
approximately 35 seconds because of the startup cost of each invocation.
With the utility rewritten to support multiple source files it now takes
approximately 1 second to scan all source files for ROM declarations.
The --exclude-driver and --exclude-driver-class options have been added,
making it possible to skip certain source files from being scanned at all.
In addition --debug option has been added to more easily trace progress.
Finally --help option was added to show usage information.
Signed-off-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Ensure drivers are disconnected when ExitBootServices() is called
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>
SHA-512/224 is almost identical to SHA-512, with differing initial
hash values and a truncated output length.
This implementation has been verified using the NIST SHA-512/224 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-512/256 is almost identical to SHA-512, with differing initial
hash values and a truncated output length.
This implementation has been verified using the NIST SHA-512/256 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-384 is almost identical to SHA-512, with differing initial hash
values and a truncated output length.
This implementation has been verified using the NIST SHA-384 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
SHA-224 is almost identical to SHA-256, with differing initial hash
values and a truncated output length.
This implementation has been verified using the NIST SHA-224 test
vectors.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Update the digest self-tests to use okx(), and centralise concepts and
data shared between tests for multiple algorithms to reduce duplicated
code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[libc] Add x86_64 versions of setjmp() and longjmp()
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>
[xhci] Support USB1 devices attached via transaction translators
xHCI provides a somewhat convoluted mechanism for specifying details
of a transaction translator. Hubs must be marked as such in the
device slot context. The only opportunity to do so is as part of a
Configure Endpoint command, which can be executed only when opening
the hub's interrupt endpoint.
We add a mechanism for host controllers to intercept the opening of
hub devices, providing xHCI with an opportunity to update the internal
device slot structure for the corresponding USB device to indicate
that the device is a hub. We then include the hub-specific details in
the input context whenever any Configure Endpoint command is issued.
When a device is opened, we record the device slot and port for its
transaction translator (if any), and supply these as part of the
Address Device command.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ehci] Support USB1 devices attached via transaction translators
Support low-speed and full-speed devices attached to a USB2 hub. Such
devices use a transaction translator (TT) within the USB2 hub, which
asynchronously initiates transactions on the lower-speed bus and
returns the result via a split completion on the high-speed bus.
We make the simplifying assumption that there will never be more than
sixteen active interrupt endpoints behind a single transaction
translator; this assumption allows us to schedule all periodic start
splits in microframe 0 and all periodic split completions in
microframes 2 and 3. (We do not handle isochronous endpoints.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Reset endpoints without waiting for a new transfer to be enqueued
The current endpoint reset logic defers the reset until the caller
attempts to enqueue a new transfer to that endpoint. This is
insufficient when dealing with endpoints behind a transaction
translator, since the transaction translator is a resource shared
between multiple endpoints.
We cannot reset the endpoint as part of the completion handling, since
that would introduce recursive calls to usb_poll(). Instead, we
add the endpoint to a list of halted endpoints, and perform the reset
on the next call to usb_step().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The endpoint may already have enqueued TRBs at the time that
xhci_endpoint_reset() is called. Ring the doorbell to resume
processing these TRBs immediately, rather than waiting until the next
call to xhci_endpoint_message() or xhci_endpoint_stream().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several of the USB timeouts were chosen on the principle of "pick an
arbitrary but ridiculously large value, just to be safe". It turns
out that some of the timeouts permitted by the USB specification are
even larger: for example, control transactions are allowed to take up
to five seconds to complete.
Fix up these USB timeout values to match those found in the USB2
specification.
Debugged-by: Robin Smidsrød <robin@smidsrod.no>
Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Do not release ownership back to BIOS when booting an OS
xHCI (and EHCI) nominally provide a mechanism for releasing ownership
of the host controller back to the BIOS, which can then potentially
restore legacy USB keyboard functionality.
This is a rarely used code path, since most operating systems claim
ownership and never attempt to later return to the BIOS. On some
systems (observed with a Lenovo X1 Carbon), this code path leads to
obscure and interesting bugs: if the xHCI and EHCI controllers are
both claimed and later released back to the BIOS, then a subsequent
call to INT 16,0305 to set the keyboard repeat rate to a non-default
value will lock the system.
Obscure though this sequence of operations may sound, it is exactly
what happens when using iPXE to boot a Linux kernel via a USB network
card. There is old and probably unwanted code in Linux's
arch/x86/boot/main.c which sets the keyboard repeat rate (with the
accompanying comment "Set keyboard repeat rate (why?)"). When booting
Linux via a USB network card on a Lenovo X1 Carbon, the system
therefore locks up immediately after jumping to the kernel's entry
point.
Work around this problem by preventing the release of ownership back
to the BIOS if it is known that we are shutting down to boot an OS.
This should allow legacy USB keyboard functionality to be restored if
the user chooses to exit iPXE, while avoiding the rarely used code
paths (and corresponding BIOS bugs) if the user chooses instead to
boot an OS.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[autoboot] Match against parent devices when matching by bus type and location
When using iPXE as an option ROM for a PCI USB controller (e.g. via
qemu's "-device nec-usb-xhci,romfile=..." syntax), the ROM prefix will
set the PCI bus:dev.fn address of the USB controller as the PCI
autoboot device. This will cause iPXE to fail to boot from any
detected USB network devices, since they will not match the autoboot
bus type (or location).
Fix by allowing the autoboot bus type and location to match against
the network device or any of its parent devices. This allows the
match to succeed for USB network devices attached to the selected PCI
USB controller.
Reported-by: Dan Ellis <Dan.Ellis@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Forcibly disable SMIs if BIOS fails to release ownership
If the BIOS fails to gracefully release ownership of the xHCI
controller, we can forcibly claim it by disabling all SMIs via the
USB legacy support control/status register.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[smsc75xx] Move RX FIFO overflow message to DBGLVL_EXTRA
RX FIFO overflow is almost inevitable since the (usable) USB2 bus
bandwidth is approximately one quarter of the Ethernet bandwidth.
Avoid flooding the console with RX FIFO overflow messages in a
standard debug build.
With TCP SACK implemented, the RX FIFO overflow no longer causes a
catastrophic drop in throughput. Experimentation shows that HTTP
downloads now progress at a fairly smooth 250Mbps, which is around the
maximum speed attainable for a USB2 NIC.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcp] Implement support for TCP Selective Acknowledgements (SACK)
The TCP Selective Acknowledgement option (specified in RFC2018)
provides a mechanism for the receiver to indicate packets that have
been received out of order (e.g. due to earlier dropped packets).
iPXE often operates in environments in which there is a high
probability of packet loss. For example, the legacy USB keyboard
emulation in some BIOSes involves polling the USB bus from within a
system management interrupt: this introduces an invisible delay of
around 500us which is long enough for around 40 full-length packets to
be dropped. Similarly, almost all 1Gbps USB2 devices will eventually
end up dropping packets because the USB2 bus does not provide enough
bandwidth to sustain a 1Gbps stream, and most devices will not provide
enough internal buffering to hold a full TCP window's worth of
received packets.
Add support for sending TCP Selective Acknowledgements. This provides
the sender with more detailed information about which packets have
been lost, and so allows for a more efficient retransmission strategy.
We include a SACK-permitted option in our SYN packet, since
experimentation shows that at least Linux peers will not include a
SACK-permitted option in the SYN-ACK packet if one was not present in
the initial SYN. (RFC2018 does not seem to mandate this behaviour,
but it is consistent with the approach taken in RFC1323.) We ignore
any received SACK options; this is safe to do since SACK is only ever
advisory and we never have to send non-trivial amounts of data.
Since our TCP receive queue is a candidate for cache discarding under
low memory conditions, we may end up discarding data that has been
reported as received via a SACK option. This is permitted by RFC2018.
We follow the stricture that SACK blocks must not report data which is
no longer held by the receiver: previously-reported blocks are
validated against the current receive queue before being included
within the current SACK block list.
Experiments in a qemu VM using forced packet drops (by setting
NETDEV_DISCARD_RATE to 32) show that implementing SACK improves
throughput by around 400%.
Experiments with a USB2 NIC (an SMSC7500) show that implementing SACK
improves throughput by around 700%, increasing the download rate from
35Mbps up to 250Mbps (which is approximately the usable bandwidth
limit for USB2).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
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>
[smsc75xx] Add driver for SMSC/Microchip LAN75xx USB Ethernet NICs
This driver is functional but any downloads via a TCP-based protocol
tend to perform poorly. The 1Gbps Ethernet line rate is substantially
higher than the 480Mbps (in practice around 280Mbps) provided by USB2,
and the device has only 32kB of internal buffer memory. Our 256kB TCP
receive window therefore rapidly overflows the RX FIFO, leading to
multiple dropped packets (usually within the same TCP window) and
hence a low overall throughput.
Reducing the TCP window size so that the RX FIFO does not overflow
greatly increases throughput, but is not a general-purpose solution.
Further investigation is required to determine how other OSes
(e.g. Linux) cope with this scenario. It is possible that
implementing TCP SACK would provide some benefit.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Most devices expose at least the link up/down status via a bit in a
MAC register, since the MAC generally already needs to know whether or
not the link is up. Some devices (e.g. the SMSC75xx USB NIC) expose
this information to software only via the MII registers.
Provide a generic mii_check_link() implementation to check the BMSR
and report the link status via netdev_link_{up,down}().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown