ESP8266 HTTP Server Side Events and Minimal OTA

Uses BSD Sockets API to listen for incoming connections

Accepts text/event-stream from client and sends event:progress updates to the client.

Uses esp_log_set_putchar to send console log to HTTP client using SSE

Accepts POST for bin file upload. Intended for ESP8266, so it checks the entry address in the first 8 bytes received. Espressif expect you to;

Have OTA partition at 0x10000 and one at 0x110000 (for > 1MB flash sizes)
If it's < 1MB, then use make ota which will compile the app bound for app1 with the modified entry address.
But they haven't modified the CMakeLists.txt file to do the same.

Otherwise, you get this error;

esp_ota_ops: **Important**: The OTA binary link data is error, please refer to document <<ESP8266_RTOS_SDK/examples/system/ota/README.md>> for how to generate OTA binaries

In order to use OTA on 1MB ESP8266, replace lines 96,97 in components/esp8266/CMakeLists.txt from

partition_table_get_partition_info(app_offset "--partition-boot-default" "offset")
partition_table_get_partition_info(app_size "--partition-boot-default" "size")

if (DEFINED PARTITION_NAME)
   partition_table_get_partition_info(app_offset "--partition-name ${PARTITION_NAME}" "offset")
   partition_table_get_partition_info(app_size "--partition-name ${PARTITION_NAME}" "size")
else()
   partition_table_get_partition_info(app_offset "--partition-boot-default" "offset")
   partition_table_get_partition_info(app_size "--partition-boot-default" "size")
endif()
message(STATUS "Using partition located at offset " ${app_offset} " with size " ${app_size})

And in your project's main CmakeLists.txt file (the program that will end up in OTA_1) add the following

set(PARTITION_NAME app1)

where app1 is the label of your OTA_1 partition defined in your partitions csv.

ESP App Description

This code will check the first 8 bytes received to ensure

It has a valid Magic Byte of 0xE9 as the first byte
It has the correct entry address (as described above)

In order for this to work, ESP8266 RTOS SDK had the modifications made in commit 525c34b. However, the linker script has the .rodata .desc being saved in the wrong memory area. For the code to work, the esp_app_desc data must be shifted into the .text section.

Open file components/esp8266/ld/esp8266.project.ld.in and move the following lines from 200 to line 168;

*(.rodata_desc .rodata_desc.*)
*(.rodata_custom_desc .rodata_custom_desc.*)

mriksman/esp88266-sse-ota

ESP8266 HTTP Server Side Events and Minimal OTA

ESP App Description