I am encountering a memory access issue in my application, which runs on Azure RTOS on a custom STM32F767VIT6‑based target board. The application receives JPEG images from an MQTT broker via the EC200U modem, using USART on the board.
The problem arises when I declare a global array of size 180 KB to store the image. Even though I initialize this array with valid non‑zero content (JPEG image data in hex), the debugger consistently shows all zeros when I attempt to read it.
Interestingly, when I reduce the array size to 100 KB, the behavior is normal — the data is correctly written and read. I am using the ST‑Link 2.0 debugger from STMicroelectronics, and the project is built in STM32CubeIDE.
Since my JPEG images can be as large as 180 KB, I need to resolve this memory limitation. Could you provide detailed guidance on the root cause of this issue and possible solutions? I have attached my workspace in .7z format for reference.
