[realtek-ambz2] Fix missing flash API resource lock unit

cores/realtek-ambz2/base/fixups/hal_flash.h

@@ -0,0 +1,13 @@
+/* Copyright (c) Kuba Szczodrzyński 2023-05-31. */
+
+// - flash_api.c and flash_api_ext.c are both compiled in libambz2_sdk.a
+// - the former declares weak functions 'flash_resource_lock' and 'flash_resource_unlock',
+//   while the latter actually implements them
+// - for some reason, the linker resolves the weak functions only,
+//   and doesn't include them in the final binary
+
+#include_next "hal_flash.h"
+
+// try to remove the weak attribute
+#undef __weak
+#define __weak

cores/realtek-ambz2/misc/rtl8710c_ram.ld

@@ -385,5 +385,11 @@ SECTIONS
 	PROVIDE(__sram_end__ = __StackLimit);
 
 	/* Check if data + heap + stack exceeds RAM limit */
-	/* TODO:	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack") */
+	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
+	ASSERT(__bss_start__ >= __ram_code_text_end__, "sram heap will overwrite sram text")
+	ASSERT(__bss_start__ >= __ram_code_rodata_end__, "sram heap will overwrite sram rodata")
+	ASSERT(__bss_start__ >= __data_end__, "sram heap will overwrite sram data")
+	ASSERT(__psram_bss_start__ >= __psram_code_text_end__, "psram heap will overwrite psram text")
+	ASSERT(__psram_bss_start__ >= __psram_code_rodata_end__, "psram heap will overwrite psram rodata")
+	ASSERT(__psram_bss_start__ >= __psram_data_end__, "psram heap will overwrite psram data")
 }