The OTA operation as implemented by Broadcom, doens't support updating DCT (it does support loading the factory reset DCT though). However eventually the DCT is just another binary blob that the user can received and store and load. To check how load a DCT, have a look at functions
wiced_dct_restory_factoryreset in WICED/platform/MCU/wiced_dct_internal_common.c
Can Anybody tell what will be the maximum size of binary for OTA??
STM32F205 which is used in Wiced wifi board has 1MB of Flash so is it possible that we can do 1MB of application code using OTA..
Waiting for your reply?
The 1MB flash will hold all the applications that you can boot from. So it will usually inlcude your factory reset application, which is a read only application that you don't every update, but can boot from in case something wrong happens and you lost your current running application (during update for example). There is also the factory reset DCT. which is the default configuration. you main OTA application can come next. I'd say those are the minimum 3 files that you need to store. Other options include adding a read only resource file system, or a WiFi firmware ware image, etc. The sum off sizes of all the files should be less than 1MB.
The Multiapp file system which control all those files in the flash, requires 1 sector (4 K). The rest is for your files.
Hope this answers your question.