1.10.1. Mailbox Client HAL API
To use the HAL API, enable altera_safeclib in the BSP Software Package from BSP Editor for Intel® Quartus® Prime Pro Edition software version prior to 21.4. Enter mailbox_client_open() function to start the HAL API. Note that the interrupt connection to the processor is necessary to use the HAL API.
The absolute addressing to the quad SPI memory specifies all the offset-related variables. You must complete the quad SPI operation by calling mailbox_client_flash_open() before any flash operation, and mailbox_client_flash_close() at the end of any flash operation.