csky: Add C based string functions

Try to access RAM with the largest bit width possible, but without
doing unaligned accesses.

A further improvement could be to use multiple read and writes as the
assembly version was trying to do.

Tested on a BeagleV Starlight with a SiFive U74 core, where the
improvement is noticeable.

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Co-developed-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/csky/abiv2/Makefile b/arch/csky/abiv2/Makefile
index c561efa5533c..ea8005fe01a8 100644
--- a/arch/csky/abiv2/Makefile
+++ b/arch/csky/abiv2/Makefile
@@ -2,9 +2,11 @@
 obj-y				+= cacheflush.o
 obj-$(CONFIG_CPU_HAS_FPU)	+= fpu.o
 obj-y				+= memcmp.o
+ifeq ($(CONFIG_HAVE_EFFICIENT_UNALIGNED_STRING_OPS), y)
 obj-y				+= memcpy.o
 obj-y				+= memmove.o
 obj-y				+= memset.o
+endif
 obj-y				+= strcmp.o
 obj-y				+= strcpy.o
 obj-y				+= strlen.o