[librm] Ensure that inline code symbols are unique
Commit 6149e0a ("[librm] Provide symbols for inline code placed into
other sections") may cause build failures due to duplicate label names
if the compiler chooses to duplicate inline assembly code.
Fix by using the "%=" special format string to include a
guaranteed-unique number within the label name.
The "%=" will be expanded only if constraints exist for the inline
assembly. This fix therefore requires that all REAL_CODE() fragments
use a (possibly empty) constraint list.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
For some CPUID leaves (e.g. %eax=0x00000004), the result depends on
the input value of %ecx. Allow this subfunction number to be
specified as a parameter to the cpuid() wrapper.
The subfunction number is exposed via the ${cpuid/...} settings
mechanism using the syntax
${cpuid/<subfunction>.0x40.<register>.<function>}
e.g.
${cpuid/0.0x40.0.0x0000000b}
${cpuid/1.0x40.0.0x0000000b}
to retrieve the CPU topology information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the active timer (providing udelay() and currticks()) to be
selected at runtime based on probing during the INIT_EARLY stage of
initialisation.
TICKS_PER_SEC is now a fixed compile-time constant for all builds, and
is independent of the underlying clock tick rate. We choose the value
1024 to allow multiplications and divisions on seconds to be converted
to bit shifts.
TICKS_PER_MS is defined as 1, allowing multiplications and divisions
on milliseconds to be omitted entirely. The 2% inaccuracy in this
definition is negligible when using the standard BIOS timer (running
at around 18.2Hz).
TIMER_RDTSC now checks for a constant TSC before claiming to be a
usable timer. (This timer can be tested in KVM via the command-line
option "-cpu host,+invtsc".)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This code largely inspired by tap.c. Allows for testing iPXE on real
NICs from within Linux. For example:
make bin-x86_64-linux/af_packet.linux
valgrind ./bin-x86_64-linux/af_packet.linux --net af_packet,if=eth3
Tested as x86_64 and i386 binary.
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>
[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>
[librm] Add phys_call() wrapper for calling code with physical addressing
Add a phys_call() wrapper function (analogous to the existing
real_call() wrapper function) for calling code with flat physical
addressing, and use this wrapper within the PHYS_CODE() macro.
Move the relevant functionality inside librm.S, where it more
naturally belongs.
The COMBOOT code currently uses explicit calls to _virt_to_phys and
_phys_to_virt. These will need to be rewritten if our COMBOOT support
is ever generalised to be able to run in a 64-bit build.
Specifically:
- com32_exec_loop() should be restructured to use PHYS_CODE()
- com32_wrapper.S should be restructured to use an equivalent of
prot_call(), passing parameters via a struct i386_all_regs
- there appears to be no need for com32_wrapper.S to switch between
external and internal stacks; this could be omitted to simplify
the design.
For now, librm.S continues to expose _virt_to_phys and _phys_to_virt
for use by com32.c and com32_wrapper.S. Similarly, librm.S continues
to expose _intr_to_virt for use by gdbidt.S.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The bulk of the iPXE binary (the .textdata section) is physically
relocated at runtime to the top of the 32-bit address space in order
to allow space for an OS to be loaded. The relocation is achieved
with the assistance of segmentation: we adjust the code and data
segment bases so that the link-time addresses remain valid.
Segmentation is not available (for normal code and data segments) in
long mode. We choose to compile the C code with -mcmodel=kernel and
use a link-time address of 0xffffffffeb000000. This choice allows us
to identity-map the entirety of the 32-bit address space, and to alias
our chosen link-time address to the physical location of our .textdata
section. (This requires the .textdata section to always be aligned to
a page boundary.)
We simultaneously choose to set the 32-bit virtual address segment
bases such that the link-time addresses may simply be truncated to 32
bits in order to generate a valid 32-bit virtual address. This allows
symbols in .textdata to be trivially accessed by both 32-bit and
64-bit code.
There is no (sensible) way in 32-bit assembly code to generate the
required R_X86_64_32S relocation records for these truncated symbols.
However, subtracting the fixed constant 0xffffffff00000000 has the
same effect as truncation, and can be represented in a standard
R_X86_64_32 relocation record. We define the VIRTUAL() macro to
abstract away this truncation operation, and apply it to all
references by 32-bit (or 16-bit) assembly code to any symbols within
the .textdata section.
We define "virt_offset" for a 64-bit build as "the value to be added
to an address within .textdata in order to obtain its physical
address". With this definition, the low 32 bits of "virt_offset" can
be treated by 32-bit code as functionally equivalent to "virt_offset"
in a 32-bit build.
We define "text16" and "data16" for a 64-bit build as the physical
addresses of the .text16 and .data16 sections. Since a physical
address within the 32-bit address space may be used directly as a
64-bit virtual address (thanks to the identity map), this definition
provides the most natural access to variables in .text16 and .data16.
Note that this requires a minor adjustment in prot_to_real(), which
accesses .text16 using 32-bit virtual addresses.
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>
[serial] Check for UART existence in uart_select()
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>
[vram] Add "vram" built-in setting to dump video RAM
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>
[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>
[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>
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>
[settings] Explicitly separate the concept of a completed fetched setting
The fetch_setting() family of functions may currently modify the
definition of the specified setting (e.g. to add missing type
information). Clean up this interface by requiring callers to provide
an explicit buffer to contain the completed definition of the fetched
setting, if required.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Expose CPUID instruction via settings mechanism
Allow CPUID values to be read using the syntax
${cpuid/<register>.<function>}
For example, ${cpuid/2.0x80000001} will give the value of %ecx after
calling CPUID with %eax=0x80000001. Values for <register> are encoded
as %eax=0, %ebx=1, %ecx=2, %edx=3.
The numeric encoding is more sophisticated than described above,
allowing for settings such as the CPU model (obtained by calling CPUID
with %eax=0x80000002-0x80000004 inclusive and concatenating the values
returned in %eax:%ebx:%ecx:%edx). See the source code for details.
The "cpuvendor" and "cpumodel" settings provide easy access to these
more complex CPUID settings.
This functionality is intended to complement the "cpuid" command,
which allows for testing individual CPUID feature bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcpip] Add faster algorithm for calculating the TCP/IP checksum
The generic TCP/IP checksum implementation requires approximately 10
CPU clocks per byte (as measured using the TSC). Improve this to
approximately 0.5 CPU clocks per byte by using "lodsl ; adcl" in an
unrolled loop.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The "rep" prefix can be used with an iteration count of zero, which
allows the variable-length memcpy() to be implemented without using
any conditional jumps.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[crypto] Add big-integer library for RSA calculations
RSA requires modular exponentiation using arbitrarily large integers.
Given the sizes of the modulus and exponent, all required calculations
can be done without any further dynamic storage allocation. The x86
architecture allows for efficient large integer support via inline
assembly using the instructions that take advantage of the carry flag
(e.g. "adcl", "rcrl").
This implemention is approximately 80% smaller than the (more generic)
AXTLS implementation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[pci] Use single "busdevfn" field in struct pci_device
Merge the "bus" and "devfn" fields into a single "busdevfn" field, to
match the format used by the majority of external code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown