feat(partition_table): Update partition table script and OTA example

1. APP binary supports 4KB align instead of 64KB align

2. Add options to sdkconfig.defaults:
2.1. using 1MB flash
2.2. use custom partition table "partitions_two_ota.1MB.mini.csv"
2.3. custom partition table base address is 0x4000

3. "make ota flash" using APP1_OFFSET as app downloading address

examples/system/universal_ota/README.md

@@ -16,6 +16,65 @@ In this example, the ESP8266 has 2 images in flash: OTA_0, OTA_1. Each of these
 Flashing the example over serial with "make flash" updates the OTA_0 app image. On first boot, the bootloader loads this OTA_0 app image which then performs an OTA update (triggered in the example code). The update downloads a new image from an http server and saves it into the OTA_1 partition. At this point the example code updates the ota_data partition to indicate the new app partition, and reboots. The bootloader reads ota_data, determines the new OTA image has been selected, and runs it.
 
 
+# Custom partition configuration
+
+If customers want to use their own partition tables with specific partition location. Please see following steps:
+
+## Step 1: Create partition file
+
+Create a partition managment file with "cvs" formate, please refer to "doc/en/api-guides/partition-tables.rst"
+
+## Step 2: Select custom partition mode
+
+1. Select custom partition tables at "menuconfig":
+
+```
+Partition Table  --->
+    Partition Table (XXXXXX)  --->
+        (X) Custom partition table CSV
+```
+
+2. Configurate custom partition location at:
+
+```
+(XXXXXX)Custom partition CSV file
+```
+
+Note: System will add the absolute path of the project to the head of the "Custom partition CSV file" automatically when compling.
+
+3. Configurate patition table location if necessary:
+
+```
+(XXXXXX)Partition table offset address at flash
+```
+
+## Step 3: Configurate application location:
+
+Configurate application location at "mennuconfig" like following base on partition table file.
+
+If you select 1MB flash, application location configuration menu is like following:
+
+```
+Partition Table  --->
+
+    [*] Support to setup partition parameter of APP2
+    (0x5000) App1 offset address 
+    (0x7B000) App1 size by bytes 
+    (0x85000) App2 offset address
+    (0x7b000) App2 size by bytes
+```
+
+If you select 2MB flash and above size, application location configuration menu is like following:
+
+```
+Partition Table  --->
+
+    (0x10000) APP1 partition offset
+    (0xF0000) APP1 partition size(by bytes)
+```
+
+Note: The firmware location information must be same as partition table file. **make ota flash** will only download the app1 at **APP1 partition offset**.
+
 # Workflow
 
 The OTA_workflow.png diagram demonstrates the overall workflow:
@@ -84,6 +143,8 @@ Serial flasher config  --->
         (X) 1 MB
 ```
 
+Configurate the application location information and it must be same as the OTA example's information, how to do refer to **Step 3: Configurate application location** of **Custom partition configuration**.
+
 Save your changes, and type `make` to build the example.
 
 ## Step 4: Flash OTA Example

examples/system/universal_ota/partitions_two_ota.1MB.mini.csv

@@ -0,0 +1,9 @@
+# Name,   Type, SubType, Offset,   Size, Flags
+# Note: if you change the phy_init or app partition offset, make sure to change the offset in Kconfig.projbuild
+# Bootloader is at 0x0000 - 0x4000, total 16KB
+# Partition table is at 0x4000 - 0x5000, total 4KB
+phy_init, data, phy,     0x5000,   0x1000
+ota_0,    0,    ota_0,   0x6000,   0x7A000
+nvs,      data, nvs,     0x80000,  0x4000
+otadata,  data, ota,     0x84000,  0x2000
+ota_1,    0,    ota_1,   0x86000,  0x7A000

examples/system/universal_ota/sdkconfig.defaults

@@ -1,4 +1,12 @@
 # Default sdkconfig parameters to use the ESP8266 OTA
-CONFIG_ESPTOOLPY_FLASHSIZE_2MB=y
-CONFIG_PARTITION_TABLE_TWO_OTA=y
 CONFIG_LWIP_SOCKET_MULTITHREAD=
+
+CONFIG_ESPTOOLPY_FLASHSIZE_1MB=y
+
+CONFIG_PARTITION_TABLE_CUSTOM=y
+CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="partitions_two_ota.1MB.mini.csv"
+CONFIG_PARTITION_TABLE_OFFSET=0x4000
+CONFIG_APP1_OFFSET=0x6000
+CONFIG_APP1_SIZE=0x7A000
+CONFIG_APP2_OFFSET=0x86000
+CONFIG_APP2_SIZE=0x7A000