u-boot/arch/arc/Kconfig
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

97 lines
1.9 KiB
Plaintext

menu "ARC architecture"
depends on ARC
config SYS_ARCH
default "arc"
config USE_PRIVATE_LIBGCC
default y
config SYS_CPU
default "arcv1"
choice
prompt "CPU selection"
default CPU_ARC770D
config CPU_ARC750D
bool "ARC 750D"
select ARC_MMU_V2
help
Choose this option to build an U-Boot for ARC750D CPU.
config CPU_ARC770D
bool "ARC 770D"
select ARC_MMU_V3
help
Choose this option to build an U-Boot for ARC770D CPU.
endchoice
choice
prompt "MMU Version"
default ARC_MMU_V3 if CPU_ARC770D
default ARC_MMU_V2 if CPU_ARC750D
config ARC_MMU_V2
bool "MMU v2"
depends on CPU_ARC750D
help
Fixed the deficiency of v1 - possible thrashing in memcpy sceanrio
when 2 D-TLB and 1 I-TLB entries index into same 2way set.
config ARC_MMU_V3
bool "MMU v3"
depends on CPU_ARC770D
help
Introduced with ARC700 4.10: New Features
Variable Page size (1k-16k), var JTLB size 128 x (2 or 4)
Shared Address Spaces (SASID)
endchoice
config CPU_BIG_ENDIAN
bool "Enable Big Endian Mode"
default n
help
Build kernel for Big Endian Mode of ARC CPU
config SYS_ICACHE_OFF
bool "Do not use Instruction Cache"
default n
config SYS_DCACHE_OFF
bool "Do not use Data Cache"
default n
config ARC_CACHE_LINE_SHIFT
int "Cache Line Length (as power of 2)"
range 5 7
default "6"
depends on !SYS_DCACHE_OFF || !SYS_DCACHE_OFF
help
Starting with ARC700 4.9, Cache line length is configurable,
This option specifies "N", with Line-len = 2 power N
So line lengths of 32, 64, 128 are specified by 5,6,7, respectively
Linux only supports same line lengths for I and D caches.
choice
prompt "Target select"
config TARGET_TB100
bool "Support tb100"
config TARGET_ARCANGEL4
bool "Support arcangel4"
config TARGET_AXS101
bool "Support axs101"
endchoice
source "board/abilis/tb100/Kconfig"
source "board/synopsys/Kconfig"
source "board/synopsys/axs101/Kconfig"
endmenu