Fix ld symbols import

Avoid linking syscall.c.o object twice and allow using precompiled core

Author: facchinm

platform.txt

@@ -69,7 +69,7 @@ recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.S.flags} -mcpu={b
 recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{archive_file_path}" "{object_file}"
 
 ## Combine gc-sections, archives, and objects
-recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" {compiler.c.elf.flags} -mcpu={build.mcu} "-T{build.variant.path}/{build.ldscript}" "-Wl,-Map,{build.path}/{build.project_name}.map" {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" "-L{build.path}" -lm -lgcc -mthumb -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--warn-section-align -Wl,--warn-unresolved-symbols -Wl,--start-group "{build.path}/core/syscalls.c.o" {object_files} -Wl,--whole-archive  "{build.variant.path}/{build.variant_system_lib}" -Wl,--no-whole-archive "{build.path}/{archive_file}" -Wl,--end-group
+recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" {compiler.c.elf.flags} -mcpu={build.mcu} "-T{build.variant.path}/{build.ldscript}" "-Wl,-Map,{build.path}/{build.project_name}.map" {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" "-L{build.path}" -mthumb -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--warn-section-align -Wl,--warn-unresolved-symbols -Wl,--start-group {object_files} -Wl,--whole-archive  "{build.variant.path}/{build.variant_system_lib}" -Wl,--no-whole-archive "{build.path}/{archive_file}" -Wl,--end-group -lm -lgcc
 
 ## Create eeprom
 recipe.objcopy.eep.pattern=

variants/otto/link-tools/common.inc

@@ -171,6 +171,17 @@ SECTIONS
         _end = __bss_end__;
       } > REGION_BSS
 
+
+    .heap : {
+        __heap_start__ = .;
+        end = __heap_start__;
+        _end = end;
+        __end = end;
+        KEEP(*(.heap))
+        __heap_end__ = .;
+        __HeapLimit = __heap_end__;
+    } > REGION_HEAP
+
     /*
      * Debugging sections
      */

variants/otto/link-tools/flash.ld

@@ -15,6 +15,7 @@ REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
 REGION_ALIAS("REGION_RODATA", rom);
+REGION_ALIAS("REGION_HEAP", ram);
 
 _FLASH_BUILD = 1;
 INCLUDE common.inc

variants/otto/link-tools/jtag.ld

@@ -17,6 +17,7 @@ REGION_ALIAS("REGION_TEXT", rom);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
 REGION_ALIAS("REGION_RODATA", rom);
+REGION_ALIAS("REGION_HEAP", ram);
 
 _FLASH_BUILD = 1;
 INCLUDE common.inc

variants/otto/link-tools/ram.ld

@@ -16,5 +16,6 @@ REGION_ALIAS("REGION_TEXT", ram);
 REGION_ALIAS("REGION_DATA", ram);
 REGION_ALIAS("REGION_BSS", ram);
 REGION_ALIAS("REGION_RODATA", ram);
+REGION_ALIAS("REGION_HEAP", ram);
 
 INCLUDE common.inc