This patch extends the protection domain framework with an additional
plugin to use Task-State Segment (TSS) structures to offload much of
the work of switching protection domains to the CPU. This can save
space compared to paging, since paging requires two 4KiB page tables
and one 32-byte page table plus one whole-system TSS and an additional
32-byte data structure for each protection domain, whereas the
approach implemented by this patch just requires a 128-byte data
structure for each protection domain. Only a small number of
protection domains will typically be used, so
n * 128 < 8328 + (n * 32).
For additional information, please refer to cpu/x86/mm/README.md.
GCC 6 is introducing named address spaces for the FS and GS segments
[1]. LLVM Clang also provides address spaces for the FS and GS
segments [2]. This patch also adds support to the multi-segment X86
memory management subsystem for using these features instead of inline
assembly blocks, which enables type checking to detect some address
space mismatches.
[1] https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html
[2] http://llvm.org/releases/3.3/tools/clang/docs/LanguageExtensions.html#target-specific-extensions
This patch adds support for optionally building EFI binaries in
addition to Multiboot ELF binaries. It includes a script,
build_uefi.sh, that downloads tool and library sources from the EDK II
project, builds the GenFw tool that is used to create UEFI binaries,
and creates a makefile that is included from the main x86 common
makefile and enables UEFI support in the Contiki build system. If the
script is not run prior to building Contiki, then an informational
message will be displayed with instructions for running build_uefi.sh
if UEFI support is desired. This patch also adds the path to the
auto-generated makefile to .gitignore.
This patch modifies the linker script for the Intel Quark X1000 to
account for the output file section offsets and alignment expectations
of the EDK II GenFw project.
This patch also adds a newlib patch to remove the weak symbol
attribute from floating point stdio support routines. See
<newlib>/newlib/README for an explanation of how the newlib developers
intended for _printf_float and _scanf_float to be linked. Newlib
declares them as weak symbols with the intention that developers would
force them to be linked only when needed using a linker command line
option. However, some but not all Contiki programs require them, so
we cannot simply always include or exclude them. Instead, we remove
the weak symbol attributes and rely on the linker to automatically
determine whether or not they should be linked. This avoids an issue
in which weak symbols were undefined in the intermediate DLL generated
as part of the UEFI build process. That resulted in the GenFw program
emitting "ERROR 3000" messages when it encountered relocations
referencing such an undefined symbol.
Finally, this patch updates README.md to both make some revisions to
account for the UART support introduced in previous patches as well as
to provide instructions for using the UEFI support.
This patch changes Galileo's buildsystem to print the elf sections
sizes after a new image is built. This way we can easily track how
these sections increase or decrease after any change.
To achieve that, we define a custom linking rule which is pretty much
the same as the default linking rule define in Makefile.include, but
we run 'size' command after the image is built.
This patch the 'debug' rule to simplify the debugging process. This new
rule runs OpenOCD and gdb with the right parameters. OpenOCD runs in
background and its output will be redirected to a log file in the
application's path called LOG_OPENOCD. Once gdb client is detached,
OpenOCD is terminated.
The 'debug' rule is defined in Makefile.customrules-galileo file (create
by this patch) which is included by the Contiki's buildsystem. So to
debug a Contiki application for Galileo board, run the following command:
$ make TARGET=galileo debug
If you use a gdb front-end, you can define the "GDB" environment variable
and your gdb front-end will be used instead of default gdb. For instance,
if you want to use cgdb front-end, just run the command:
$ make BOARD=galileo debug GDB=cgdb
