Add flash for vtable destination, make it default

Add an option for placing vtables in flash to complement the existing
iram and heap options.  "make flash"

Now that there is a way to change it, move to vtables in flash as default
as only users with interrupts which use vtables require the vtable to
be in RAM.  For those users, if the tables are small enough they can put
them in IRAM and save heap space for their app.  If not, then the vtables
can be placed in HEAP which supports much larger tables.

tools/sdk/ld/Makefile

@@ -5,7 +5,8 @@ WARN = "\/\* warning: AUTOGENERATED from $(COMMON)\*.h \*\/"
 
 all:
 	@echo "available rules:"
-	@echo "  iram: move c++ vtables to iram (= default in git master repository)"
+	@echo "  flash: move c++ vtables to flash (= default in git master repository)"
+	@echo "  iram: move c++ vtables to iram"
 	@echo "  heap: move c++ vtables to heap"
 
 heap:
@@ -15,3 +16,7 @@ heap:
 iram:
 	@(echo "$(WARN)"; $(CPP) -CC -E -DVTABLES_IN_IRAM $(COMMON).h | grep -v '^#') > $(COMMON)
 	@echo "c++ vtables moved to iram"
+
+flash:
+	@(echo "$(WARN)"; $(CPP) -CC -E -DVTABLES_IN_FLASH $(COMMON).h | grep -v '^#') > $(COMMON)
+	@echo "c++ vtables moved to flash"

tools/sdk/ld/eagle.app.v6.common.ld

@@ -95,6 +95,9 @@ SECTIONS
     *(.ver_number)
     *.c.o( EXCLUDE_FILE (umm_malloc.c.o) .literal*, EXCLUDE_FILE (umm_malloc.c.o) .text* )
     *.cpp.o(.literal*, .text*)
+
+    *(.rodata._ZTV*) /* C++ vtables */
+
     *libc.a:(.literal .text .literal.* .text.*)
     *libm.a:(.literal .text .literal.* .text.*)
     *libgcc.a:_umoddi3.o(.literal .text)
@@ -159,7 +162,7 @@ SECTIONS
     *.cpp.o(.iram.text)
     *.c.o(.iram.text)
 
-    *(.rodata._ZTV*) /* C++ vtables */
+
 
     *(.fini.literal)
     *(.fini)

tools/sdk/ld/eagle.app.v6.common.ld.h

@@ -94,6 +94,9 @@ SECTIONS
     *(.ver_number)
     *.c.o( EXCLUDE_FILE (umm_malloc.c.o) .literal*, EXCLUDE_FILE (umm_malloc.c.o) .text* )
     *.cpp.o(.literal*, .text*)
+#ifdef VTABLES_IN_FLASH
+    *(.rodata._ZTV*) /* C++ vtables */
+#endif
     *libc.a:(.literal .text .literal.* .text.*)
     *libm.a:(.literal .text .literal.* .text.*)
     *libgcc.a:_umoddi3.o(.literal .text)
@@ -167,7 +170,7 @@ SECTIONS
     _etext = .;
   } >iram1_0_seg :iram1_0_phdr
 
-#ifdef VTABLES_IN_IRAM
+#if defined(VTABLES_IN_IRAM) || defined(VTABLES_IN_FLASH)
 #include "eagle.app.v6.common.ld.vtables.h"
 #endif