integrate general improvements from Ossc Pro

* OSD timing optimizations and cursor color selection
* flash robustness fixes

software/sys_controller_bsp/Makefile

@@ -136,7 +136,10 @@ BSP_CFLAGS_OPTIMIZATION = -Os
 
 # C/C++ compiler warning level. "-Wall" is commonly used.This setting defines
 # the value of BSP_CFLAGS_WARNINGS in Makefile.
-BSP_CFLAGS_WARNINGS = -Wall
+BSP_CFLAGS_WARNINGS = -Wall -Wno-unused-but-set-variable -Wno-unused-variable -Wno-unused-function
+
+# Match APP flags
+BSP_CFLAGS_USER_FLAGS := -fdata-sections -ffunction-sections -fshort-enums -fgnu89-inline -flto -msmall-data-limit=0
 
 # C compiler command.
 CC = riscv64-unknown-elf-gcc -xc