Provide wrapper macros to allow efi_open() and related functions to
accept a pointer to any pointer type as the "interface" argument, in
order to allow a substantial amount of type adjustment boilerplate to
be removed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When DEBUG=efi_wrap is enabled, we construct a patched copy of the
boot services table and patch the global system table to point to this
copy. This ensures that any subsequently loaded EFI binaries will
call our wrappers.
Previously loaded EFI binaries will typically have cached the boot
services table pointer (in the gBS variable used by EDK2 code), and
therefore will not pick up the updated pointer and so will not call
our wrappers. In most cases, this is what we want to happen: we are
interested in tracing the calls issued by the newly loaded binary and
we do not want to be distracted by the high volume of boot services
calls issued by existing UEFI drivers.
In some circumstances (such as when a badly behaved OEM driver is
causing the system to lock up during the ExitBootServices() call), it
can be very useful to be able to patch the global boot services table
in situ, so that we can trace calls issued by existing drivers.
Restructure the wrapping code to allow wrapping to be enabled or
disabled at any time, and to allow for patching the global boot
services table in situ.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The debug wrappers for CloseEvent() and CheckEvent() are currently
both calling SignalEvent() instead (presumably due to copy-paste
errors). Astonishingly, this has generally not prevented a successful
boot in the (very rare) case that DEBUG=efi_wrap is enabled.
Fix the wrappers to call the intended functions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
On some systems (observed with an HP Elitebook 840 G10), writing
console output that happens to cause the display to scroll will modify
the system memory map. This causes builds with DEBUG=efi_wrap to
typically fail to boot, since the debug output from the wrapped
ExitBootServices() call itself is sufficient to change the memory map
and therefore cause ExitBootServices() to fail due to an invalid
memory map key.
Work around these UEFI firmware bugs by prescrolling the display after
a failed ExitBootServices() attempt, in order to minimise the chance
that further scrolling will happen during the subsequent attempt.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The EDK2 header macros VA_START(), VA_ARG() etc produce build errors
on some CPU architectures (notably on 32-bit RISC-V, which is not yet
supported by EDK2).
Fix by using the standard variable argument list macros.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The EFI loaded image protocol allows an image to be provided with a
custom system table, and we currently use this mechanism to wrap any
boot services calls made by the loaded image in order to provide
strace-like debugging via DEBUG=efi_wrap.
The ExitBootServices() call will modify the global system table,
leaving the loaded image using a system table that is no longer
current. When DEBUG=efi_wrap is used, this generally results in the
machine locking up at the point that the loaded operating system calls
ExitBootServices().
Fix by modifying the global EFI system table to point to our wrapper
functions, instead of providing a custom system table via the loaded
image protocol.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A successful call to ExitBootServices() will result in the EFI console
becoming unusable. Ensure that the EFI wrapper produces a complete
line of debug output before calling the wrapped ExitBootServices()
method, and attempt subsequent debug output only if the call fails.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow temporary debugging code to call efi_wrap_systab() to obtain a
pointer to the wrapper EFI system table. This can then be used to
e.g. forcibly overwrite the boot services table pointer used by an
already loaded and running UEFI driver, in order to trace calls made
by that driver.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add debug wrappers for more boot services functions, and print
symbolic values rather than raw numbers where possible.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The raw EFI_HANDLE value is almost never useful to know, and simply
adds noise to the already verbose debug messages. Improve the
legibility of debug messages by using only the name generated by
efi_handle_name().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Propagate our modified EFI system table to any images loaded by the
image that we wrap, thereby allowing us to observe boot services calls
made by all subsequent EFI images.
Also show details of intercepted ExitBootServices() calls. When
wrapping is used, exiting boot services will almost certainly fail,
but this at least allows us to see when it happens.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When building with DEBUG=efi_wrap, print details of calls made by the
loaded image to selected boot services functions.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown