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4 Commits

Author SHA1 Message Date
Paul Burton e245767abf
MIPS: Use a custom elf-entry program to find kernel entry point
For a long time arch/mips/Makefile used nm to discover the kernel entry
point by looking for the address of the kernel_entry symbol. This
doesn't work for systems which make use of bit 0 of the PC to reflect
the ISA mode - ie. microMIPS (and MIPS16, but we don't support building
kernels that target MIPS16 anyway).

So for a while with commit 5fc9484f5e ("MIPS: Set ISA bit in entry-y
for microMIPS kernels") we manually modified the last nibble of the
output from nm, which worked but wasn't particularly pretty.

Commit 27c524d174 ("MIPS: Use the entry point from the ELF file
header") then cleaned this up by using objdump to print the ELF entry
point which includes the ISA bit, rather than using nm to print the
address of the kernel_entry symbol which doesn't. That removed the ugly
replacement of the last nibble, but added its own ugliness by needing to
manually sign extend in the 32 bit case.

Unfortunately it has been pointed out that objdump's output is
localised, and therefore grepping for its "start address" output doesn't
work when the user's language settings are such that objdump doesn't
print in English.

We could simply revert commit 27c524d174 ("MIPS: Use the entry point
from the ELF file header") and return to the manual replacement of the
last nibble of entry-y, but it seems that was found sufficiently
unpalatable to avoid. We could attempt to force the language used by
objdump by setting an environment variable such as LC_ALL, but that
seems fragile. Instead we add a small tool named elf-entry which simply
prints out the entry point of the kernel in the format we require.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: Philippe Reynes <philippe.reynes@softathome.com>
Tested-by: Philippe Reynes <philippe.reynes@softathome.com>
Fixes: 27c524d174 ("MIPS: Use the entry point from the ELF file header")
Patchwork: https://patchwork.linux-mips.org/patch/20322/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
2018-08-30 09:39:22 -07:00
Paul Burton fb615d61b5 Update MIPS email addresses
MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list.  An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@mips.com>
Acked-by: Dengcheng Zhu <dengcheng.zhu@mips.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-03 09:02:30 -07:00
Paul Burton e1270575fb MIPS: Fix generic-board-config.sh for builds using O=
When configuring the kernel using one of the generic MIPS defconfig
targets, the generic-board-config.sh script is used to check
requirements listed in board config fragments against a reference config
in order to determine which board config fragments to merge into the
final config.

When specifying O= to configure in a directory other than the kernel
source directory, this generic-board-config.sh script is invoked in the
directory that we are configuring in (ie. the directory that O equals),
and the path to the reference config is relative to the current
directory. The script then changes the current directory to the source
tree, which unfortunately breaks later access to the reference file
since its path is relative to a directory that is no longer the current
working directory. This results in configuration failing with errors
such as:

  $ make ARCH=mips O=tmp 32r2_defconfig
  make[1]: Entering directory '/home/pburton/src/linux/tmp'
  Using ../arch/mips/configs/generic_defconfig as base
  Merging ../arch/mips/configs/generic/32r2.config
  Merging ../arch/mips/configs/generic/eb.config
  grep: ./.config.32r2_defconfig: No such file or directory
  grep: ./.config.32r2_defconfig: No such file or directory
  The base file '.config' does not exist.  Exit.
  make[1]: *** [arch/mips/Makefile:505: 32r2_defconfig] Error 1
  make[1]: Leaving directory '/home/pburton/src/linux-ingenic/tmp'
  make: *** [Makefile:145: sub-make] Error 2

Fix this by avoiding changing the working directory in
generic-board-config.sh, instead using full paths to files under
$(srctree)/ where necessary.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: 27e0d4b051 ("MIPS: generic: Allow filtering enabled boards by requirements")
Cc: linux-mips@linux-mips.org
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: kbuild-all@01.org
Patchwork: https://patchwork.linux-mips.org/patch/17231/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-10-09 16:32:34 +02:00
Paul Burton 27e0d4b051 MIPS: generic: Allow filtering enabled boards by requirements
Up until now when configuring a generic kernel all board config
fragments have been merged by default unless boards are explicitly
selected by the user specifying BOARDS=.

In many cases this is sub-optimal, since some boards don't make sense to
include in some kernels. For example the MIPS SEAD-3 development board
has only ever been used with 32 bit CPUs, so including support for the
SEAD-3 in a 64 bit kernel is wasteful.

This patch introduces support for specifying requirements in board
config fragments, using comments formatted like so:

  # require CONFIG_BLA=y

For example the SEAD-3 board could specify that it should only be merged
for 32 bit kernels using a requirement line like the following:

  # require CONFIG_32BIT=y

A new generic-board-config.sh script is introduced to handle selecting
the board config fragments to merge & calling merge_config.sh to merge
them. In order to allow requirements to check Kconfig symbols that are
implicitly selected, rather than explicitly specified by
generic_defconfig or one of the ISA config fragments, an intermediate
.config file is saved & used as a reference when checking requirements.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16943/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-30 00:57:28 +02:00