[core] Provide entire flash as "root" partition

arduino/libretuya/common/main.cpp

@@ -5,6 +5,11 @@
 
 using namespace arduino;
 
+extern "C" {
+#include <fal.h>
+fal_partition_t fal_root_part = NULL;
+}
+
 // Weak empty variant initialization function.
 // May be redefined by variant files.
 void initVariant() __attribute__((weak));
@@ -32,6 +37,10 @@ int main(void) {
 	__libc_init_array();
 	// optionally initialize per-variant code
 	initVariant();
+	// initialize FAL
+	fal_init();
+	// provide root partition
+	fal_root_part = (fal_partition_t)fal_partition_find("root");
 	// start the main task and OS kernel
 	startMainTask();
 

arduino/libretuya/port/flashdb/fal_cfg.h

@@ -2,6 +2,8 @@
 
 #pragma once
 
+#include <fal_def.h>
+
 // Flash device configuration
 extern const struct fal_flash_dev flash0;
 
@@ -23,3 +25,8 @@ extern const struct fal_flash_dev flash0;
 		.offset		= FLASH_##part_upper##_OFFSET, /* partition offset macro as uppercase string */                    \
 		.len		= FLASH_##part_upper##_LENGTH, /* partition length macro as uppercase string */                    \
 	},
+
+/**
+ * @brief Root partition table, representing the entire flash.
+ */
+extern fal_partition_t fal_root_part;

builder/utils/flash.py

@@ -11,6 +11,9 @@ def env_add_flash_layout(env, board):
         defines = {}
         flash_size = 0
         fal_items = ""
+        # add "root" partition
+        fal_items += "FAL_PART_TABLE_ITEM(root, ROOT)"
+        # add all partitions
         for name, layout in flash_layout.items():
             name = name.upper()
             (offset, _, length) = layout.partition("+")
@@ -19,6 +22,10 @@ def env_add_flash_layout(env, board):
             fal_items += f"FAL_PART_TABLE_ITEM({name.lower()}, {name})"
             flash_size = max(flash_size, int(offset, 16) + int(length, 16))
         defines["FLASH_LENGTH"] = flash_size
+        # for "root" partition
+        defines["FLASH_ROOT_OFFSET"] = 0
+        defines["FLASH_ROOT_LENGTH"] = flash_size
+        # add partition table array
         defines["FAL_PART_TABLE"] = "{" + fal_items + "}"
         env.Append(CPPDEFINES=list(defines.items()))
         env.Replace(**defines)