Merge branch 'feature/bootloader_refactoring_common' into 'master'

bootloader: Refactoring

See merge request idf/esp-idf!2251

docs/en/api-guides/bootloader.rst

@@ -0,0 +1,15 @@
+Bootloader
+=====================
+
+Bootloader performs the following functions:
+
+1. Minimal initial configuration of internal modules;
+2. Select the application partition to boot, based on the partition table and ota_data (if any);
+3. Load this image to RAM (IRAM & DRAM) and transfer management to it.
+
+Bootloader is located at the address `0x1000` in the flash.
+
+Customer bootloader
+---------------------
+The current bootloader implementation allows the customer to override it. To do this, you must copy the folder `/esp-idf/components/bootloader` and then edit `/your_project/components/bootloader/subproject/main/bootloader_main.c`.
+

docs/en/api-guides/index.rst

@@ -13,6 +13,7 @@ API Guides
    Thread Local Storage <thread-local-storage>
    High Level Interrupts <hlinterrupts>
    JTAG Debugging <jtag-debugging/index>
+   Bootloader <bootloader>
    Partition Tables <partition-tables>
    Secure Boot <../security/secure-boot>
    ULP Coprocessor <ulp>