kernel_optimize_test/arch/xtensa
Chris Zankel 78f3cdfa2a xtensa: Fix linker script to include .literal sections
Fix resembles implementation from Marc Gauthier and Piet Denaly:

In the Xtensa architecture, assembly generates literals which must always
precede the code (the L32R instruction that loads them only uses negative
PC-relative offsets).  For any *.text section, literals are placed in a
corresponding *.literal section.  The linker script (vmlinux.lds) must
place these in the correct order.  It must also combine them, when the
*.text section can be larger than L32R's 256 kB range.

For example, this doesn't work:  *(.literal) *(.text) because L32R
instructions at the end of .text can't reach the literals.

The linker can solve this if they are combined in parentheses, like this:
       *(.literal .text)
because it is now allowed mix literals in .text to bring them in range.

None of this is done by standard vmlinux.lds.h macros such as TEXT_TEXT
and INIT_TEXT.  To avoid replicating the logic of that header file, we
instead post-process the generated linker script to convert *(xxx.text)
to *(xxx.literal xxx.text) for the following text sections:
       .text .ref.text .*init.text .*exit.text .text.*
using a sed script.  To do this we must override the default rule for
vmlinux.lds (see scripts/Makefile.build and the top-level Makefile)
to insert this extra step.

Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Pete Delaney <piet@tensilica.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
2009-05-11 23:40:33 -07:00
..
boot xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
configs xtensa: update s6105_defconfig for ccount calibration 2009-05-11 22:00:22 -07:00
include/asm xtensa: fix wrong extern declaration renamed in code using it 2009-05-11 22:00:11 -07:00
kernel xtensa: Fix linker script to include .literal sections 2009-05-11 23:40:33 -07:00
lib xtensa: move headers files to arch/xtensa/include 2008-11-06 10:25:09 -08:00
mm xtensa: nommu support 2009-04-02 23:41:50 -07:00
platforms xtensa: register gpio chip before use 2009-05-11 22:00:07 -07:00
variants xtensa: implement ccount calibration for s6000 2009-05-11 22:00:17 -07:00
Kconfig xtensa: implement ccount calibration for s6000 2009-05-11 22:00:17 -07:00
Kconfig.debug
Makefile xtensa: only build platform or variant if they contain a Makefile 2009-04-03 00:06:45 -07:00