genode/base-codezero/patches

This directory contains patches of the Codezero kernel that are needed for the
integration with Genode. Furthermore, some patches address issues with recent
tool chains not yet supported by the official Codezero verison.

:binutils-2.21.patch:

  The GNU assembler of binutils-2.21 complains with an error that was ignored
  by previous binutils versions:

  "Error: .size expression for ... does not evaluate to a constant"

  This error seems to occur if the argument of 'BEGIN_PROC' does not match
  the argument of 'END_PROC'. The patch fixes such inconsistencies in the
  code.

:gcc_shared_enabled.patch:

  Codezero expect the tool chain to be used for the kernel to not support
  shared libraries. This is the case for Codesourcery's arm-non-eabi
  tool chain. Such tool chains use to incorporate both libgcc and libgcc_eh
  into the single libgcc.a library. In contrast, for tool chains built with
  '--enable-shared', libgcc does not contain the functions of libgcc_eh. Hence,
  one symbol called '__aeabi_unwind_cpp_pr0' referenced by libgcc and normally
  provided by libgcc_eh remains unresolved. There are two possible solutions
  for this problem: We could link libgcc_eh to the 'final.elf' image as
  expected by libgcc. However, this way, we will need to implement the
  the environment expected by libgcc_eh. For Codezero, this is pointless
  because no C++ is used. The second option is to provide a dummy symbol
  for '__aeabi_unwind_cpp_pr0' just to make the linker happy. This patch
  adds such a dummy symbol to 'loader/main.c'.

:libc_search_dir.patch:

  The userlibs are build with w/o '-nostdinc'. Consequently, the standard
  search paths of the tool chain are used. Because the user land is
  normally build with the Codesourcery tool chain 'arm-none-linux-gnueabi',
  the complete glibc headers (that come with the tool chain) end up in
  the default search path. Coincidentally, the userlibs SConstruct file
  misses to supply the Codezero libc headers, which goes undetected because
  headers such as 'stdio.h' are silently taken from the tool chain's libc.
  This patch supplies Codezero's libc include-search path for building
  the userlibs. This enables the userlibs to be built with tool chains
  that do not come with a complete libc.

:scons-2.0.1.patch:

  SCons 2.0.1 complains about the 'build_dir' argument being renamed to
  'variant_dir'. This patch renames the argument where needed for building
  the kernel and the default container.

:set_fixed_pager.patch:

  At some point, Codezero abandoned the facility to define the pager for a
  given thread via the exregs system call. Instead, the kernel hard-wires the
  creator of the thread as the thread's pager. This is conflicting with
  Genode's way of creating and paging threads. On the current version of Genode
  for Codezero, all threads are paged by one thread (thread 3 happens to be the
  global pager) within core. As a work-around to Codezero's current limitation,
  we define thread 3 to be the pager of all threads.

:gcc_4_6_1_fixes.patch:

  Version 4.6.1 of GCC is more picky about dead code than previous versions and
  warns about unused variables. Because Codezero is build with the '-Werror'
  flag, these warnings cause the kernel build to fail. The patch fixes those
  warnings by removing the variables in question.