Initial (untested) implementation of config in flash 16kb (#14107)

src/platform/PICO/config_flash.c

@@ -0,0 +1,68 @@
+/*
+ * This file is part of Betaflight.
+ *
+ * Betaflight is free software. You can redistribute this software
+ * and/or modify this software under the terms of the GNU General
+ * Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * Betaflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+
+#include "platform.h"
+#include "drivers/system.h"
+#include "config/config_streamer.h"
+
+#include "hardware/flash.h"
+#include "hardware/sync.h"
+
+#if defined(CONFIG_IN_FLASH)
+
+static uint32_t interrupts;
+
+void configUnlock(void)
+{
+    // NOOP
+}
+
+void configLock(void)
+{
+    // NOOP
+}
+
+void configFlashClearFlags(void)
+{
+    // NOOP
+}
+
+configStreamerResult_e configWriteWord(uintptr_t address, config_streamer_buffer_type_t value)
+{
+    if (address == __config_start) {
+        // Erase the flash sector before writing
+        flash_range_erase(address, FLASH_PAGE_SIZE);
+    }
+
+    STATIC_ASSERT(CONFIG_STREAMER_BUFFER_SIZE == sizeof(uint32_t) * 1,  "CONFIG_STREAMER_BUFFER_SIZE does not match written size");
+
+    // TODO: refactor to stream the entire buffer to flash also possibly avoid disabling interrupts.
+    // Write data to flash
+    // TODO: synchronise second core...
+    uint32_t interrupts = save_and_disable_interrupts();
+    flash_range_program(address, (uint8_t*)&value, sizeof(uint32_t));
+    restore_interrupts(interrupts);
+    return CONFIG_RESULT_SUCCESS;
+}
+
+#endif // CONFIG_IN_FLASH