Commit graph

16 commits

Author SHA1 Message Date
Alexey Brodkin
fac4790491 arc: Eliminate unused code and data with GCC's garbage collector
Finally GCC's garbage collector works on ARC so let's use it.
That's what I may see for HSDK:

Before:
   text	   data	    bss	    dec	    hex	filename
 290153	  10068	 222616	 522837	  7fa55	u-boot

After:
   text	   data	    bss	    dec	    hex	filename
 261999	   9460	 222360	 493819	  788fb	u-boot

Overall ~5% of memory footprint saved.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2018-03-21 16:21:34 +03:00
Alexey Brodkin
d53b128df4 arc: Fix final linkage with Elf32 tools
ARC Elf32 tools by default enable usage of so-called "small data"
section or in ARC PRM parlance "GP-relative addressing".

The idea is to put up to 2kB of frequently used data into a separate
location and use indirect addressing via dedicated core register (GP).
Where GP is used as a base for offset calculation.

And so if "-msdata" toggle is passed to the compiler either explicitly
or implicitly (that's Elf32 tools case) it will try to put some data
in that "small data" area and then to calculate real offset from GP
to be encoded in instructions we need to know the base value which
liker gets from __SDATA_BEGIN__ symbol in hte linker script.

In U-Boot we don't use that feature and linker script doesn't define
__SDATA_BEGIN__ which gives us the following linkage error if we use
Elf32 tools:
------------------------->8-------------------
  LD      u-boot
.../bin/arc-elf32-ld.bfd: Error: Linker symbol __SDATA_BEGIN__ not found
.../bin/arc-elf32-ld.bfd: final link failed: Bad value
------------------------->8-------------------

Note if uClibc or glibc tools are used that problem doesn't happen
because usage of "small data section" is disabled by default as not very
useful for bigger executables. Moreover GP is just another name of r26
so we're loosing 1 core register which is not used by the compiler as a
generic register with "-msdata".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2018-02-15 15:44:47 +03:00
Alexey Brodkin
7c8d816053 arc: Use -mcpu=XXX instead of obsolete -marcXXX
With newer ARC tools old way of CPU specification gets obsolete,
so we're switching to newer and more common way of setting "-mcpu".

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2016-09-16 12:12:26 +03:00
Alexey Brodkin
7a54f5177a arc: Use "-mcpu=archs" instead of deprecated "-marchs" for ARC HS
Newer ARC toolchains don't support "-marchs" option any longer.
Instead "-mcpu=archs" should be used. What's also important older
toiolchains that support ARC HS cores will also happily accept
"-mcpu=archs" so that's a very safe move.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2016-07-04 11:43:40 +03:00
Masahiro Yamada
574bbf4f68 arc: use more universal prefix for default CROSS_COMPILE
As doc/README.ARC says, pre-build ARC toolchains are available at
the Synopsys GitHub page.

The bin files are prefixed with arc(eb)-buildroot-linux- for earlier
releases, but with arc(eb)-snps-linux- for the latest releases.

The symbolic links prefixed with arc(eb)-linux- are also available
for all the release, so those prefixes can be used as the default
CROSS_COMPILE regardless of the toolchains version/variants.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2015-05-13 13:44:25 +03:00
Masahiro Yamada
0a12e6872e generic-board: move __HAVE_ARCH_GENERIC_BOARD to Kconfig
Move the option to Kconfig renaming it to CONFIG_HAVE_GENERIC_BOARD.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>
2015-03-28 09:03:08 -04:00
Alexey Brodkin
f13606b77d arc: introduce U-Boot port for ARCv2 ISA
ARC HS and ARC EM are new cores based on ARCv2 ISA which is binary
incompatible with ISAv1 (AKA ARCompact).

Significant difference between ISAv2 and v1 is implementation of
interrupt vector table.

In v1 it is implemented in the same way as on many other architectures -
as a special location where user may put whether code executed in place
(if machine word of space is enough) or jump to a full-scale interrupt
handler.

In v2 interrupt table is just an array of adresses of real interrupt
handlers. That requires a separate section for IVT that is not encoded
as code by assembler.

This change adds support for following cores:
 * ARC EM6 (simple 32-bit microcontroller without MMU)
 * ARC HS36 (advanced 32-bit microcontroller without MMU)
 * ARC HS38 (advanced 32-bit microcontroller with MMU)

As a part of ARC HS38 new version of MMU (v4) was introduced.

Also this change adds AXS131 board which is the same DW ARC SDP base board but
with ARC HS38 CPU tile.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2015-02-13 09:17:51 +03:00
Alexey Brodkin
a67ef280f4 arc: build libgcc in U-Boot
This way we may have very limited set of functions implemented so we
save some space.

Also it allows us to build U-Boot for any ARC core with the same one
toolchain because we don't rely on pre-built libgcc.

For example:
 * we may use little-endian toolchain but build U-Boot for ether
endianess
 * we may use non-multilibbed uClibc toolchain but build U-Boot for
whatever ARC CPU flavour that current GCC supports

Private libgcc built from generic C implementation contributes only 144
bytes to .text section so we don't see significant degradation of size:
--->8---
$ arc-linux-size u-boot.libgcc-prebuilt
   text	   data	    bss	    dec	    hex	filename
 222217	  24912	 214820	 461949	  70c7d	u-boot.libgcc-prebuilt

$ arc-linux-size u-boot.libgcc-private
   text	   data	    bss	    dec	    hex	filename
 222361	  24912	 214820	 462093	  70d0d	u-boot.libgcc-private
--->8---

Also I don't notice visible performance degradation compared to
pre-built libgcc (where at least "*div*" functions are had-written in
assembly) on typical operations of downloading 10Mb uImage over TFTP and
bootm.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2015-02-09 16:41:20 +03:00
Alexey Brodkin
51f4999bc5 arc: move CPU flags selection to the main "config.mk"
As a preparation to ARCv2 port submission we're moving CPU slection
flags to a common location.
Also it will allow us to have more flexible CPU specification, not only
ISA version but CPU family as well checking CONFIG_ARC_CPU_xxx.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2015-02-09 16:41:20 +03:00
Alexey Brodkin
1f9ad44546 arc: add selection of endianess in Kconfig
This change allows to keep board description clean and minimalistic.
This is especially helpful if one board may house different CPUs with
different features.

It is applicable to both FPGA-based boards or those that have CPUs
mounted on interchnagable daughter-boards.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2015-02-09 16:41:20 +03:00
Alexey Brodkin
812980bdd6 arc: add more flavours of ARC700 series CPU
Now we may select a particular version of ARC700:
 * ARC750D or
 * ARC770D

It allows more flexible (or more fine tuned) configuration of U-Boot.
Before that change we relied on minimal configuration but now we may
use specific features of each CPU.

Moreover allows us to escape manual selection of options that
exist in both CPUs but may have say different version like MMUv2 in
ARC750D vs MMUv3 in ARC770D.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
2015-02-09 16:41:20 +03:00
Alexey Brodkin
dcb431e723 arc: add dependences on MMU presence
Depending on MMU presence in CPU there're differences in HW behavior.
For example address of instruction that caused exception is put in
ECR register if MMU exists and in ERET register otherwise.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Igor Guryanov <guryanov@synopsys.com>
2015-01-15 22:38:42 +03:00
Masahiro Yamada
90f984e397 kconfig: delete redundant CONFIG_${ARCH} definition
CONFIG_${ARCH} is defined by Kconfig.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2014-07-30 14:42:02 -04:00
Masahiro Yamada
323762e54a kbuild: delete redundant LDSCRIPT definition
$(SRCTREE)/$(CPUDIR)/u-boot.lds is our default location
of arch-specific linker script.

Remove redundant definitions in
arch/{arc,microblaze,openrisc}/config.mk.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Acked-by: Michal Simek <monstr@monstr.eu>
2014-03-12 17:04:46 -04:00
Masahiro Yamada
9b6e2c363f kbuild: fix CROSS_COMPILE settings in config.mk
The syntax
  CROSS_COMIPLE ?= <cross_compiler_prefix>
does not work because config.mk is parsed after
exporting CROSS_COMPILE.

Like Linux Kernel's arch/$(ARCH)/Makefile,
we must write as follows:

  ifeq ($(CROSS_COMPILE),)
  CROSS_COMPILE := <cross_compiler_prefix>
  endif

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-03-04 12:15:30 -05:00
Alexey Brodkin
2f16ac9df4 arc: add cpu files
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Francois Bedard <fbedard@synopsys.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Heiko Schocher <hs@denx.de>
2014-02-07 08:14:32 -05:00